Whitehill Bordon Sustainability Strategy Overarching Sustainability, Energy, Waste and Climate Change Adaptation
East Hampshire District Council October 2009
Prepared by: ................................................ Giorgia Franco Senior Consultant Sarah Bryant Consultant Helen Pearce Senior Consultant Georgia Arnott Principal Consultant
Approved by: ................................................. Rob Shaw Associate Director Ben Smith Associate Director
Whitehill Bordon Sustainability Strategy Rev No 1 2
Comments
Date 19/03/09 24/09/09
Draft Draft v2
The Johnson Building, 77 Hatton Garden, London, EC1N 8JS Telephone: 020 7645 2000 Fax: 020 7645 2099 Website: http://www.fabermaunsell.com Job No 60048490
Date Created 17/01/09
This document has been prepared by AECOM Limited (“AECOM”) for the sole use of our client (the “Client”) and in accordance with generally accepted consultancy principles, the budget for fees and the terms of reference agreed between AECOM and the Client. Any information provided by third parties and referred to herein has not been checked or verified by AECOM, unless otherwise expressly stated in the document. No third party may rely upon this document without the prior and express written agreement of AECOM. f:\sdg\jobs\whitehall-bordon masterplan\05 working files\stage 6\report\090924 draft sustainability strategy.doc
Executive Summary AECOM was commissioned by East Hampshire District Council to support the development of a sustainable masterplan for the Whitehill Bordon Eco-Town by developing the energy, waste and climate change adaptation strategies for the site. As the masterplan developed it became apparent that a wider outlook was required to ensure that the proposals were developed with consideration for more than just infrastructure and design changes. This was in order to acknowledge the vital role that behavioural change and lifestyle changes have in delivering sustainable development. The first section of this report aims to provide an overview of how different aspects of our daily lives impact on the environment and contribute to our carbon footprint. It then provides some examples of what measures can be taken to reducing our impacts and how different measures compare with each other in terms of CO2 savings. The aim of this exercise was to set a list of priority measures that should be tackled first to facilitate maximum CO2 reductions from the outset. The following sections of this report pick up on some of the measures with the greatest CO2 saving potential and outline the proposed strategy for low or zero carbon energy use, waste management and climate change adaptation at the Eco-Town. The strategies have been developed after assessing the opportunities and constraints present within and around the masterplan site boundary and can be summarised as follows: Energy •
Existing homes will be retrofitted with energy efficiency measures and new homes (and non-domestic buildings) will be designed to have highly energy efficient specifications;
•
High density and non-domestic part of the development will be served by a biomass combined heat and power system coupled with a district heating network;
•
The low density part will be served by block by block biomass boilers; solar photovoltaics panels will be installed across the site for renewable electricity generation.
Waste •
Waste generation will be reduced and recycling rates will be increased via a series of initiatives aimed at tackling residents’ behaviour;
•
Recyclable waste will be transferred to the Alton Material Recovery Facility (MRF), where it is prepared and transferred for recycling;
•
Organic waste will be composted at source where possible (e.g. houses with gardens) or at a central location on site. If further investigation proves it to be viable, food waste may be used for energy generation via off-site anaerobic digestion;
•
Residual waste will be taken off site for centralised electricity generation.
Climate change adaptation •
66% of site surface area will be permeable (e.g. Green Loop, green roofs, permeable paving etc);
•
Sustainable drainage systems (SuDS) will be incorporated throughout the site and no building will take place on high flood risk areas;
•
Water demand will be limited by effective sanitary ware specifications and implementation of grey and rain water recycling;
•
Risk of overheating will be limited by careful building design and effective landscaping.
Table of Contents
Executive Summary .................................................................................................................... 2 1
Achieving Sustainable Development ............................................................................ 2 1.1 Why sustainable development is important for Whitehill Bordon ......................... 2 1.2 Whitehill Bordon’s carbon footprint ....................................................................... 2 1.3 Top 10 sustainability proposals ............................................................................ 4 1.4 Detailed strategies .............................................................................................. 11
2
Energy Strategy ............................................................................................................. 13 2.1 Energy and Carbon Objectives ........................................................................... 13 2.2 Existing infrastructure ......................................................................................... 13 2.3 Existing energy demands and supply ................................................................. 13 2.4 Opportunities for existing development .............................................................. 15 2.5 Opportunities from new development ................................................................. 19 2.6 Options – appraised using rules of thumb .......................................................... 21 2.7 Proposals and delivery implications.................................................................... 25 2.8 Next steps ........................................................................................................... 25
3
Waste strategy ............................................................................................................... 28 3.1 Waste strategy Objectives .................................................................................. 28 3.2 Existing waste management arrangements and facilities................................... 28 3.3 Likely waste arisings ........................................................................................... 29 3.4 Options - appraised using the rules of thumb ..................................................... 30 3.5 Proposals and delivery implications.................................................................... 37 3.6 Next steps ........................................................................................................... 37
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Climate Change Adaptation ......................................................................................... 39 4.1 Climate change adaptation objectives ................................................................ 39 4.2 Climate change adaptation options .................................................................... 40 4.3 Proposals and delivery implications.................................................................... 48 4.4 Next steps ........................................................................................................... 49
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Conclusions ................................................................................................................... 51 5.1 Energy ................................................................................................................. 51 5.2 Waste .................................................................................................................. 51 5.3 Climate change adaptation ................................................................................. 52 5.4 Next steps ........................................................................................................... 52
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Appendices .................................................................................................................... 54
Achieving Sustainable Development
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1 Achieving Sustainable Development
1.1 Why sustainable development is important for Whitehill Bordon It is now internationally agreed that human activity is having a lasting impact on our planet. Since the industrial revolution, our increasing consumption of fossil fuels has caused the concentration of greenhouse gases in our atmosphere to radically increase, with increasingly apparent effect on the climate. At the same time the increasing population and increasing consumption of natural resources mean that the closed system that is our planet will not be able to support our current lifestyles for much longer. It is therefore necessary for our lifestyles to change by reducing the resources we consume and moving towards the use of renewable sources of energy. The extension of a town presents a great opportunity to facilitate this lifestyle change as suitable infrastructure can be put in place for the use of renewable energy and services can be introduced to help residents make more environmentally conscious choices in their daily lives (e.g. use public transport, buy locally sourced food etc.). The development of new neighbourhoods also allows for measures to be integrated into the design that will make it easier for us to adapt to the now inevitably changing climate. The UK Government has set itself very high targets for reductions in CO2 emissions, which are the biggest cause of climate change, and it is very aware of the potential for CO2 savings that can be achieved in new building and urban development. The Government has selected four proposed Eco-towns to be at the forefront of sustainable development and has produced a planning policy statement setting out the sustainability targets that these eco-towns will meet. Whitehill Bordon is one of the Government’s selected eco-towns and East Hampshire District Council (EHDC) has set its own aspirations for the town in their Green Town Vision document. Hence sustainable development is the over-arching principle that has driven the development of the masterplan. The aim of the masterplanning process was to test the deliverability of the national eco-towns targets set by the Government and the Green Town Vision aspirations, whilst developing additional targets to capitalise on specific local opportunities.
1.2 Whitehill Bordon’s carbon footprint In order to assess how Whitehill Bordon will be performing against other towns and whether it will be exemplar, it is important to understand its current impacts on the environment. One method of assessing the environmental impacts of a person/town/country is to calculate its carbon footprint, which basically associates CO2 emissions to all actions, products and goods consumed. The carbon footprint of the average UK resident is approximately 10-11tCO2/year. Figure 1 shows how these CO2 emissions can be typically associated with different every day activities. The methodology used by the Carbon Trust to calculate the footprint takes the total CO2 emissions from the UK and divides it by the population, this way attributing to each person an equal share of the CO2 emissions from central goods and services that are being used by everyone.
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Figure 1: UK average carbon footprint per capita (source: Carbon Trust)
If we focus on the geographical area of Whitehill Bordon, the carbon footprint specific to the town today is likely to be quite different from the national average. For example it will probably have a higher proportion relating to commuting due to the lack of a rail link or good public transport, but it could be that the aviation proportion is smaller because there may not be so many business trips requiring air travel. The “other government” section would most likely be bigger because of the presence of the MoD, but the hygiene and health would probably be smaller because the local hospital is not a major, fully equipped facility. It has not been possible to calculate a bespoke carbon footprint for Whitehill Bordon at this stage, due to the extensive amount of information required to carry out a carbon footprint exercise. Nevertheless Figure 1 is helpful to understand the relative contribution of various aspects of our daily lives. In order to ensure that Whitehill Bordon develops as a low carbon community as per the Green Town Vision, major interventions will be required on all fronts; some of these can be delivered by the masterplan, others are in the control of the town’s inhabitants, but there are also some measures that have to take place at a national level (e.g. decarbonising the National Grid, as stated in The UK Low Carbon Transition Plan1, by investing in nuclear, increasing large scale renewable installations and investing in carbon capture and storage) . Starting from the breakdown of UK CO2 emissions shown in Figure 1 we have considered a variety of measures that could be implemented to reduce Whitehill Bordon’s carbon footprint. Table 1 classifies these measures according to which area of our daily life they apply to and it indicates where the responsibility for their implementation would lie.
1
http://www.decc.gov.uk/en/content/cms/publications/lc_trans_plan/lc_trans_plan.aspx
3
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Outside of WB’s control (i.e. requires national intervention)
WB masterplan & infrastructure
WB inhabitants via behavioural change
Household and space heating
Build new buildings to have zero emissions; retrofit existing buildings with energy efficiency improvements; install local renewable energy technologies
Reduce thermostat temperature by 1°C; use energy efficient light bulbs; do not leave appliances on standby or on when not in use; ban plastic bags
Hygiene and health
Provide local medical facilities in low impact buildings (e.g. high BREEAM score); provide facilities to incentivise walking and cycling; provide allotments to grow local organic food
Use local medical facilities; have showers instead of baths; wash clothes at 30°C; use low impact cleaning and washing products
Improve resource efficiency (e.g. energy, water) of hospitals and clinics
Communications
Provide broadband to facilitate home working; provide facilities for community uses
Work from home sometimes to reduce commuting
Improve efficiency of communication systems (e.g. broadband, satellites)
Education
Build new schools to have zero emissions; retrofit existing schools with energy efficiency improvements; facilitate walking/cycling/taking the bus to school; make schools exemplar projects promoting “green” living
Walk or cycle to school; include “green” activities in the curriculum; involve parents as well as children to maximise education potential
Other government
Council owned buildings to lead by example in low consumption
Aviation
Provide easy connections to local amenity and vacation sites; provide good communications to reduce need for business trips
Reduce air travel or replace with rail or car; offset emissions from air travel
Recreation and leisure
Improve recreation facilities in the area; provide green spaces
Choose low impact activities (e.g. cycling over go-carting, archery over laser quest)
Clothing and footwear
Provide affordable premises for small local businesses (e.g. craft workshops, charity shops)
Buy locally; buy low impact products
Regulate packaging and manufacturing; support and promote low impact products
Food and catering
Avoid sending food waste to landfill; provide allotments, private gardens and farmers’ market
Reduce food wastage; have a vegetable patch in the garden; buy local food; lobby for reduced packaging
Regulate packaging and carbon footprint of food; regulate agricultural practice
Commuting
Public transport link; cycle lanes; pedestrian areas; connectivity to other regions
Modal shift from private car to walking, cycling, public transport; car clubs; ecodriving; electric cars
Promote large scale renewables and nuclear (i.e. decarbonise the National Grid); make government buildings more energy efficient
Improve fuel efficiency; improve aircraft design
Table 1: CO2 saving measures and their applicability
1.3 Top 10 sustainability proposals The measures listed in Table 1 have very different cost and CO2 savings associated with them; not all of these are easily quantifiable, however we have attempted to do this for a number of
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them, to show the relative contribution that each can make to reduce the carbon footprint of Whitehill Bordon. The results of our calculations in terms of predicted CO2 savings and their relation to the UK average carbon footprint are given in Table 2 and Table 3. % saving against UK average per capita footprint
Assumptions
2,000
Making all new Zero carbon new buildings zero carbon buildings (domestic and with biomass CHP and solar PV non-domestic)
Improving wall, roof and window insulation and installing solar water heating to all existing dwellings
Measure
Description
Running cost saving
Cost per tonne of CO2 saved
0.7%
Based on actual generation of 2MW turbine on the M4
n/a unless run as a community turbine. "Green tariffs" are generally more expensive than standard tariffs
medium/low
16,000
5.6%
AECOM calculations
n/a
high
11,500
4.0%
AECOM calculations
£35-£240/dwelling/year = up to £1.5 million across WB
medium/high
Discount on Council Tax?
low
n/a
medium/low
tonnes of CO2 saved per year
Notes
Whitehill Bordon masterplan & infrastructure
2MW wind turbine
Retrofitting energy efficiency to existing housing
Installing a 2MW wind turbine on HCC land
Composting and/or AD Not sending food facilities to ensure that waste to landfill no food waste is sent to decompose in a landfill
1,700
0.6%
Use the concrete to be removed from MoD land to produce aggregates for construction
2,400
0.8%
Reuse of concrete from demolition
This measure also National data from the avoids some domestic Climate Change transport emissions Committee (CCC) from taking waste to report: "Building a low landfill, this has not carbon economy" been quantified scaled down for WB CO2 savings from reuse This measure also of aggregate from avoids emissions from WRAP report on transport due to the recycling. Assumed reduction in distance 2400kg/m° concrete density and an average travelled to collect and deliver the aggregates thickness of concrete on site of 2m
Table 2: CO2 savings, assumptions and likely cost of various infrastructure measures
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Description
tonnes of CO2 saved per year
Whitehill Bordon inhabitants via behavioural change Run campaign to convince WB residents Wash at 30° 200 instead of 40° to wash their clothes at 30° rather than 40° Increasing rail and bus passenger km by 50% Modal shift in 950 and doubling cycle km transport (both replacing car travel)
6
% saving against UK average per capita footprint
Assumptions
0.1%
0.3%
Eco-driving uptake
Run campaign and provide free lessons in eco-driving (to save CO2 and money)
1,900
0.7%
Reduce thermostat temperature by 1°
Run campaign to convince WB residents to set their thermostats 1° lower in winter
2,100
0.7%
Running cost saving
Cost per tonne of CO2 saved
Carbon Trust and Tesco carbon footprinting study
Minor reduction in electricity bills
low
National data from the CCC report scaled down for WB
Depends on cost of rail and buses. Can save money for single car users. Cycling more saves petrol money
medium
typically save £50 per year per car (assuming fuel at £1.18/litre)
low
typically save £65 per household per year (ref: EST)
low
n/a
low
CCC report - average percentage fuel saving per car; assumed a 2008 Ford Focus 1.6L petrol car for every two WB inhabitants and average annual milage 7133 miles/year (ref: Office of National Statistics) Energy Saving Trust predicted savings per home, applied to existing housing in WB
Notes
Getting local residents Banning plastic and businesses involved bags in eliminating the use of plastic bags in the town
150
0.1%
Based on DEFRA data about CO2 savings per bag. Assumes each person uses 4 bags per week
Reducing the amount of food that goes to landfill by educating people only to buy what they need
700
0.2%
National data from WRAP "Love food, hate waste" scaled down for WB
on average £430/family/year = £2.8 million across WB
low
5.7%
www.co2calc.co.uk comparison of different modes of transport
International rail travel generally more expensive than low cost flights so no cost benefit
low
WRAP report: Environmental benefits of recycling - indicative This measure also emission rates from n/a for residents or avoids some domestic landfilling various possible discount on transport emissions recyclable materials Council Tax; AECOM calculations on from taking waste to Council saves on landfill landfill, this has not predicted WB waste tax been quantified arisings AECOM assumption that 80% of all waste is recyclable
low
Reducing food wastage
Replace a return flight to Europe (London to Reduce air travel Malaga) per person per year with a train journey to the same destination
Run campaigns and provide incentives (e.g. Council Tax rebates) to Achieve 80% ensure that 100% of waste recycling recyclable waste is sent rate to Alton MRF and not to landfill or energy from waste facility
16,200
2,300
0.8%
Table 3: CO2 savings, assumptions and likely cost of various behavioural change measures
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Figure 2: Relative CO2 savings from different measures (*) Against a base case assuming that the new buildings would be built to today’s Building Regulations, with no energy saving improvements.
Figure 2 clearly shows that certain measures both in terms of infrastructure and behavioural change, have greater potential than others, which has helped us to set a list of priority measures to achieve maximum savings. However it should be noted that every contribution helps towards achieving the challenging carbon reduction targets that have been set for the town, therefore ideally all measures should be promoted. Furthermore it should be remembered that many of the measures listed above have benefits that are not necessarily quantified in terms of CO2 reductions but are nonetheless important contributors to a sustainable town. For example not sending food waste to landfill and banning plastic bags will reduce the need for landfill sites therefore limiting the space requirements and pollution risk associated with them. Eco-driving uptake will allow cars to last longer therefore reducing the need to build new ones. As a result of this CO2 saving comparison the following 5 measures are considered to be top priorities to achieve CO2 reductions at Whitehill Bordon: 1. Zero carbon new buildings The Eco-towns PPS requires all buildings to have zero carbon emissions, furthermore national policy is already in place requiring new schools to be zero carbon from 2016 and there are also proposals to require non-domestic buildings to be zero carbon by 2019. Whitehill Bordon will be one of the first large developments to implement the zero carbon policy for all new buildings. It is proposed that this will be achieved by developing a district heating network powered by a biomass combined heat and power (CHP) engine that will generate heat and electricity for the site. To ensure the economic viability of the district network, areas of low density development and buildings far removed from the main area of development (e.g. leisure hub) will most likely be served by localised solutions such as building by building biomass boilers.
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Given the presence of the Forestry Commission’s HQ and the large areas of woodland in the vicinity of the town, it is expected that it will be possible to source the biomass to power the CHP system locally, therefore ensuring low transport and management emissions and local job creation. It is most likely that in order to achieve zero carbon for all buildings, significant amounts of solar photovoltaics panels will also have to be installed on the roofs of buildings. If a suitable location is found for a medium or large scale wind turbine within the development, this will be used as a more cost effective way than PV to meet some of the shortfall in savings required to ensure that the zero carbon target is met. See section 2.4 for further details. 2. Retrofitting energy efficiency to existing housing A vital part of ensuring an integrated approach to the regeneration of Whitehill Bordon is to ensure that the fabric of buildings to be retained is improved by retrofitting energy efficiency measures. Connecting existing buildings to the proposed district heating network may be viable in some instances, but it is unlikely to be possible for the majority of the existing housing due to the high capital cost associated with retrofitting a district heating network. Where connection to the network is not viable, it is proposed to reduce heat loss by improving the thermal performance of the walls, roofs and windows of existing homes. It is also proposed that boilers more than ten years old be replaced and all homes with roofs of suitable orientation will be fitted with solar water heating systems. Energy efficiency retrofit is also proposed for non-domestic buildings, although in this case the focus will be on replacement of building services as this is expected to be more cost effective than fabric improvement. This retrofit exercise has the potential to reduce the CO2 emissions from existing housing by over 40%; it will also provide significant running cost savings for the residents and will increase awareness of energy efficiency and renewable energy technologies. It is proposed that grant funding will be available from the Local Authority to encourage uptake of retrofitting measures. It should be noted that a large proportion of CO2 emissions in existing and new homes are due to appliance use (e.g. washing machines, TVs, computers, play stations etc). There is a great potential for reducing CO2 emissions by educating people to use their appliances efficiently and to be conscious in their choice of appliances to avoid unnecessary energy consumption. 3. Reduce air travel Reducing personal air travel is one of the most effective changes in behaviour that the inhabitants of Whitehill Bordon can make to reduce their carbon footprint. It is proposed that an awareness campaign is launched and incentives are put in place to promote a modal shift from air to rail or road national and international travel. A vital part of making the modal shift successful will be to provide an effective rail/light rail link to the town connecting it to the national and international rail network. Other initiatives could include promoting local holiday destinations instead of cheap deals abroad and issuing discount vouchers for rail travel. For the plane journeys that cannot be avoided, an offsetting fund could be set up specific to Whitehill Bordon with the money re-invested into CO2 savings measures within the community (e.g. retrofit of energy efficiency in existing buildings, invest in a wind farm off site and reinvest revenue in the town’s community facilities). 4. Achieve 80% waste recycling rate East Hampshire District Council currently have a recycling rate for dry waste in excess of 32%, which puts it in the top 20 district councils in the country. This success is attributable to Project Integra and the Alton Materials Recovery Facility (MRF), which is a state of the art waste sorting facility 15km from Whitehill Bordon. The presence of this facility means that it should be
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possible to increase the recycling rate and therefore reduce CO2 emissions at a relatively low cost. A new awareness campaign as part of the eco-town launch coupled with some incentives (e.g. Council Tax rebates) has the potential to significantly increase the recycling rate, therefore helping the Council meet its recycling targets and reducing Whitehill Bordon’s CO2 emissions. It has currently been assumed that even if all recyclable waste were recycled successfully, the recycling rate would only be 80% due to a 20% of non-recyclable materials. This remaining fraction could be reduced via campaigns and lobbying to supermarkets and other retailers to ensure that all unavoidable packaging is made of recyclable materials. It should be noted that improving the way garden and food waste is dealt with also has a great CO2 saving potential as decomposing green waste emits methane, which is a much more powerful greenhouse gas than CO2. The awareness campaign should promote home composting (e.g. giving away compost bins); furthermore a central composting facility is proposed for homes and non-domestic buildings that do not have the space to accommodate private facilities. Anaerobic digestion (AD) is another effective method of treating organic waste. It is commonly used within sewage treatment works and energy is often recovered from the process. The sewage works facility currently serving Bordon does not use anaerobic digestion due to the limited size of the facility. As the extension of the town progresses and the need to extend the facility arises, the feasibility of using AD with energy recovery will be evaluated including the potential of also using food waste to feed the system. 5. Reuse concrete from demolition
Although buildings will be retained and reused wherever possible, the extension and regeneration of Whitehill Bordon will involve the demolition of various buildings and existing infrastructure on the MoD land. This presents a great opportunity for converting the concrete from demolition into aggregates for the new buildings, roads etc. This will be done with due care to avoid dust generation and other negative impacts on the local residents. Concrete production is a very energy intensive process, therefore recycling existing concrete has a great CO2 reducing potential; doing so locally has the added advantage of avoiding emissions from transporting materials around the country. Reusing concrete from demolition will be only one aspect of the site waste management plan that will be in place for the duration of the project. Other measures proposed relating to minimising the impact of construction and demolition include the use of local materials (e.g. timber from Forestry Commission land) and the production of building elements locally.
In addition to the 5 items listed above, there are other measures with considerable environmental benefit that are proposed for Whitehill Bordon even if the savings associated with them are not easily quantifiable in terms of CO2 savings. These include the following:
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Improve facilities to achieve a modal shift in transport away from the private car Providing a rail/light rail link as well as improving walking and cycling facilities will enable Whitehill Bordon inhabitants to significantly reduce their CO2 emissions relating to domestic transport. The savings achieved will depend on how successful and long term the model shift is; the 950tCO2/year shown in Figure 2 is a conservative estimate. There is potential for this saving to be higher. Grow and consume food locally Growing and purchasing food locally has the potential to significantly reduce the carbon footprint of Whitehill Bordon for a number of reasons: food miles are avoided; growing on a small scale is less energy, water and fertiliser intensive than large scale farming; the energy and resource requirements of packaging are avoided; growing your own and buying locally produced food has the potential to reduce the amount of food wasted by bulk buying. Furthermore growing and buying food locally can provide considerable savings on residents’ food bills. In order to promote local food production, gardens and allotments will be provided as part of the masterplan, a farmers’ market will be integrated in the new town centre, schools will run community allotments and promotional campaigns will be run by East Hampshire District Council. Achieve net water neutrality Water treatment is a very energy intensive process meaning that considerable CO2 savings can be achieved by ensuring that potable water is only used when the high quality is required (e.g. drinking, cooking), while non-potable water is used for lower grade uses (e.g. watering plants, flushing toilets, washing clothes). This will be achieved by specifying water efficient sanitary ware and appliances and by integrating rainwater and greywater recycling in the development. The MoD site has a groundwater source that will most likely be maintained for future development at Whitehill Bordon (pending on licensing agreement from the Environment Agency) with no impact on water availability in the wider region. Furthermore specification of plants that require little water in public green spaces are proposed to reduce the need for irrigation water. More detailed information of opportunities and proposals associated with reductions in water consumption are provided in the Outline Water Cycle Study carried out by Halcrow (March 2009).
Finally, for a truly sustainable approach to the masterplan it is important to introduce measures that will ensure the development can function successfully as climate change becomes more apparent. The following measures are proposed as part of the climate change adaptation strategy: Sustainable drainage systems (SuDS) Climate change will bring more extreme weather events more frequently, this means that the risk of flooding will progressively increase. In order to mitigate this issue, it is proposed to design SuDS into the masterplan. These systems allow quick absorption of rainwater and slow excess runoff during storm events, therefore reducing the risk of flooding. Furthermore, depending on the type of system chosen, they have the potential to increase biodiversity and reduce summer overheating (by improving evapo-transpiration).
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Linked green roofs and other green infrastructure The provision of linked green roofs and other green infrastructure (e.g. Green Loop, Suitable Alternative Natural Green Spaces) will reduce summer overheating (which will become more common with the changing climate), help reduce flood risk, enhance local biodiversity and provide a pleasanter and more liveable urban environment.
1.4 Detailed strategies As sustainability is the overarching theme in the development of the Whitehill Bordon mastrplan, more details about the proposals discussed above can be found in various technical documents. Energy use, waste management and climate change adaptation are covered in this report. Transport proposals are detailed in the transport strategy carried out by Alan Baxter & Associates and issues relating to water are discussed in the water strategy carried out by Halcrow.
Energy Strategy
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2 Energy Strategy
2.1 Energy and Carbon Objectives The targets set by the Eco-Towns Planning Policy Statement (PPS) and the East Hampshire Green Town Vision were reviewed and the following were set as objectives while developing the Whitehill Bordon masterplan: •
Aspiration for the whole town to have a carbon neutral footprint by 2036;
•
Over a year the net CO2 emissions from all energy use within the buildings on the development are zero or below;
•
Aspiration for all new construction to be carbon neutral;
•
All new homes to be zero carbon as per PPS definition;
•
Achieve Code for Sustainable Homes level 4 in all dwellings as a minimum; Include real time energy monitoring systems; Demonstrate high levels of energy efficiency in the fabric of the building, having regard to proposals for standards to be incorporated into changes to the Building Regulations between now and 2016; Achieve carbon reductions (from space heating, hot water and fixed lighting) of at least 70% relative to current Building Regulations (Part L 2006);
• •
• •
Retrofit energy efficiency measures to all existing homes.
The Green Town Vision sets a number of higher targets than the ones outlined above (e.g. achieving Code Level 6 in all new homes, retrofitting all existing homes to PassivHaus standards). There is currently a lack of supporting evidence to suggest that these targets are technically and financially achievable. Detailed financial and technical analysis will be required at a later stage in development to assess whether the targets set by the Green Town Vision can be achieved in practice.
2.2 Existing infrastructure The existing town is served by standard grid electricity and the local supplier is Scottish and Southern Electric. The Whitehill Bordon baseline report states that there is sufficient electrical capacity on site to accommodate a further 4,000 dwellings, however any more dwellings may require an additional substation and major upgrade works. A preliminary assessment of utility drawings covering the MoD site showed the presence of an electrical substation located to the north of the site, in the south western corner of the playing fields to the west of Louisburg Barracks and a major substation located in the town centre, just south of the community centre (Martinique House). Most buildings are currently heated by natural gas via the national distribution network and the position statement predicts no problems or excessive costs associated with extending the gas grid, if required.
2.3 Existing energy demands and supply In order to estimate the potential for energy and CO2 savings in the part of the town that will be retained, an assessment of the current energy demands was carried out. At this stage the assessment was only done on dwellings due to the limited information available on the current and predicted commercial uses on the site. The following sources of information were used to assess the number, mix and age of the existing housing currently present in Whitehill Bordon:
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•
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The “house tenure mix recommendations” provided by East Hampshire District Council dated 16/06/08 was used to establish the predicted number of existing housing by 2009 to be 6,404 dwellings. The “Housing Statistics 2008” (CLG document) was used to establish the split by house type for the South East region. Type of accommodation (end of March 2006) semidetached terrace purpose converted mobile detached house house built flat flat home house 29% 28% 25% 12% 4% 1%
•
•
not self contained 1%
It was understood from the design team that the vast majority of existing housing in Whitehill Bordon was built during the 1960s, ‘70s and ‘80s, with a small proportion of older early 20th century properties. The latest (2006) English House Condition Survey (EHCS) was used to obtain the average floor area for different unit types. Floor area (m²) end terrace 86 mid terrace 79 small terraced house 59 medium/large terraced house 94 all terrace 83 semi-detached 91 detached house 146 bungalow 76 converted flat 65 pb flat, low rise 55 pb flat, high rise 65 Dwelling type
•
The EHCS was also used to assess the type of heating fuel most commonly used in the South East of England. heating system central heating 89.4%
•
•
storage heating 7.2%
fixed room heating 3.1%
fuel type portable heating only 0.3%
gas fired system 87.8%
oil fired system 2.6%
solid fuel electrical fired system system 0.6%
9.0%
As part of a nation-wide study for DECC on the heat use in the existing housing stock, AECOM has developed a model that looks at 42 different types of dwellings, of different ages and heated by different fuels. The model uses information from the EHCS to develop SAP models for all unit types and calculate their energy demands; furthermore the model assumes that some energy efficiency improvements would have been retrofitted to at least some existing buildings since they had been built. Three most representative dwelling types and average estimated U-values were taken from the AECOM model and used to develop a SAP model for each dwelling type. As the AECOM model did not look at detached houses, a typical new detached house layout was used, but the energy efficiency levels of an old house (taken from the AECOM model) were applied to obtain a more realistic energy demand for an existing detached house. The 4 SAP models developed were then used to extrapolate the total energy demands and CO2 emissions associated with the existing dwellings.
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Assumptions The following housing split and floor areas were assumed and applied to a total of 6,404 dwellings. semiterrace detached flat detached house house house Percentage of total 30% 28% 25% 17% Floor area (m²) 146 91 83 55 A series of assumptions were made on the likely thermal envelope characteristics of homes of the ages applicable to Bordon. As nearly 90% of housing in the South East of England is served by gas central heating, all 4 dwellings were assumed to be heated by gas. The following parameters were used to develop the SAP models for the base case unit types: units Floor Area Age Air permeability Door u-value Windows u-value Walls u-value Roof u-value Floor u-value Thermal bridging Cylinder volume Cylinder insulation Heating fuel Boiler type Boiler efficiency Secondary heating
m2 m³/m² @50Pa W/m²K W/m²K W/m²K W/m²K W/m²K m³ mm
Detached House 152 1919-1975 15 3 2.87 1.40 0.35 0.51 0.15 150 25 gas standard 85% flueless gas
Semidetached 84 1919-1975 15 3 2.87 1.40 0.35 0.51 0.15 150 25 gas standard 85% flueless gas
Terrace
Flat
85 1919-1975 15 3 2.87 1.40 0.35 0.51 0.15 150 25 gas standard 85% flueless gas
55 post 1975 15 3 2.82 0.68 0.29 0.35 0.15 120 25 gas standard 85% no
CO2 emissions The data from the 4 models was used to extrapolate energy demands and CO2 emissions for all 6,404 existing dwellings giving a predicted total of approximately 37,500 tonnes of CO2 per year.
2.4 Opportunities for existing development There are various opportunities available to reduce the CO2 emissions from existing development, for example: •
Retrofitting energy efficiency measures
•
Retrofitting building integrated renewable energy technologies
•
Connecting to a district heating network powered by a central low or zero carbon generator (e.g. gas CHP, biomass CHP, biomass boilers)
•
Using large scale renewable technologies (e.g. wind) off site to offset the CO2 emissions from the existing homes
Having produced 4 SAP models for typical house types representative of the existing stock, a number of energy efficiency and renewable energy retrofit improvements were applied to the models to establish the likely energy and CO2 savings. The savings achievable in the 4 representative unit types were then used to extrapolate the energy and CO2 savings achieved by the various energy efficiency measures proposed.
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The following energy efficiency improvements were considered: • Reduce roof U-value from 0.35 to 0.16 (i.e. increase loft insulation) • Reduce wall U-value from 1.4 to 0.5 (and 0.35 for the flat) (i.e. increase insulation in cavity and/or externally) • Reduce window U-value from 2.8 to 2.2 (i.e. replace windows for good double glazing) • Replace the existing boiler with a 90% efficient condensing boiler and retrofit TRVs (thermostatic radiator valves) • Install a solar water heating system in each dwelling, including the replacement of the hot water tank. Assumed flat plate panel of 4m2 for houses and 3m2 for flats installed on a 30°pitch with a south-east or south west orientation (i.e. not optimal). • Change the heating system to be fuelled by biomass (individual boilers for houses, communal system for flats)
Figure 3: Examples of possible retrofitting measures to existing homes (source ZEDFactory) These improvements were selected because they are relatively easy to retrofit to existing buildings. The changes were applied and the results of the model compared to the base case independently, i.e. the savings calculated for changing the boiler do not include the benefits provided by improving the U-values. This was done in order to quantify the savings for each measure assuming that only one would be implemented per dwelling; however it would be possible to combine most of these measures in the same dwelling to achieve greater savings. CO2 savings Table 4 gives the total energy use and CO2 emissions for the different unit types and for the whole site. The figures are then updated accounting for the different improvements proposed. The CO2 savings against the base case have then be calculated.
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Retrofit improvements for existing housing Total electricity consumption (kWh/year) Total gas consumption (kWh/year) Total CO2 emissions (kg CO2) Total electricity consumption (kWh/year) Total gas consumption (kWh/year) Total CO2 emissions (kg CO2)
17
Detached House
SemiTerrace detached Base case 4,930 4,170 3,754 33,209 21,228 16,804 8,523 5,878 4,844 Roof U-value from 0.35 to 0.16 4,930 4,170 3,754 32,379 20,688 16,276 8,362 5,773 4,742
Flat
All existing residential
3,240 6,553 2,639
26,484,527 135,902,679 37,541,590
3,231 6,469 2,619
26,475,315 62,206,393 36,858,871
1%
2%
3,191 6,065 2,523
26,431,417 105,625,334 31,645,372
4%
16%
3,217 6,325 2,585
26,459,654 132,086,221 36,790,701
2%
2%
3,183 5,802 2,469
26,422,191 123,418,342 35,093,323
6%
6%
7%
3,827 15,344 4,592
3,328 5,269 2,427
26,983,651 125,796,726 35,791,666
5% for flat) 3,710 15,944 1,964
8%
5%
2,980 5,179 1,387
25,959,751 129,051,488 14,181,302
59%
47%
62%
% CO2 savings against base case
2% 2% 2% Walls U-value from 1.4 to 0.5 (0.35 for flat) Total electricity consumption (kWh/year) 4,930 4,170 3,754 Total gas consumption (kWh/year) 24,500 16,648 13,803 6,833 4,989 4,262 Total CO2 emissions (kg CO2)
% CO2 savings against base case Total electricity consumption (kWh/year) Total gas consumption (kWh/year) Total CO2 emissions (kg CO2)
20% 15% 12% Windows U-value from 2.8 to 2.2 4,930 4,170 3,754 32,467 20,589 16,182 8,379 5,754 4,723
% CO2 savings against base case
2% 2% 2% 90% efficient condensing boiler + TRVs Total electricity consumption (kWh/year) 4,930 4,170 3,754 Total gas consumption (kWh/year) 30,200 19,346 15,236 7,939 5,513 4,540 Total CO2 emissions (kg CO2)
% CO2 savings against base case Total electricity consumption (kWh/year) Total gas consumption (kWh/year) Total CO2 emissions (kg CO2)
7% 6% Solar water heating 5,002 4,251 31,394 19,620 8,201 5,600
% CO2 savings against base case
4% 5% Biomass (single for houses, communal Total electricity consumption (kWh/year) 4,886 4,121 Total biomass consumption (kWh/year) 31,944 20,365 2,861 2,248 Total CO2 emissions (kg CO2)
% CO2 savings against base case
66%
62%
Table 4: Modelled CO2 savings from energy efficiency improvements and renewables. As mentioned above, the savings are calculated individually. If more than one measure were implemented within the same SAP model, the savings would be slightly different from the sum of the savings given above; this is due to the interactions between measures, e.g. improving Uvalues reduces the need for space heating so the effect of replacing the boiler with a more efficient one would be reduced. At this stage however, the savings given above have been combined to give an indicative figure of the CO2 savings that could be achieved if a variety of measures were retrofitted to the existing dwellings across the site. The analysis carried out on the existing housing stock at Whitehill Bordon shows that individual measures can provide savings from 2% to up to 62% across the domestic element of the site. Furthermore if all existing dwellings could be retrofitted with U-value improvements, upgrade of gas boilers and introduction of solar water heating, approximately 11,000 tonnes of CO2 could be saved. It should however be noted that not all measures discussed here can be retrofitted to all units. This is due to cost but also to the physical characteristics of the individual buildings. For example solar water heating is only suited to dwellings with a south facing roof (or other suitable surface for panel installation); however homes with different physical characteristics could for example be retrofitted with new gas boilers or, even better, biomass heating.
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Figure 4: Example of upgrade of south facing terrace on Apollo Drive (source ZEDFactory) The cost of retrofitting these different measures varies significantly, and so do the running cost savings for occupants. A cost benefit analysis has not been carried out for the measures at this stage, but given below is a qualitative assessment of the likely retrofit costs and running cost savings for the various measures considered. Measure
Retrofit cost
Roof U-value
low
Running cost savings low
Walls U-value
medium/high
medium/high
Window U-value
medium
low
New gas boiler Solar water
medium
medium
medium
medium
Biomass
high
low
An important issue to note in the context of the whole Whitehill Bordon development, is that retrofitting energy efficiency measures and renewables to existing homes has the potential to save as much CO2 as would be offset from making all new homes zero carbon (when measured against a base case of homes built to Building Regulations 2006). The graph below in fact shows how savings on the existing stock could be approximately equivalent to the predicted CO2 emissions from the up to 5500 proposed new homes built to 2006 Building Regulations standards. Furthermore setting up schemes for upgrading existing housing presents a great opportunity to engage existing residents to benefit from the development before the new infrastructure is in place. Energy efficiency retrofit presents a great opportunity to educate people about saving energy and promotes behavioural change.
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Figure 5: Comparison of CO2 emissions from new and existing housing and potential savings from efficiency retrofit (*) Base case of housing built to 2006 Building Regulations
2.5 Opportunities from new development The preferred strategy to achieve a zero carbon new development on site is to use a combination of the following: •
Passive design (e.g. north-south orientation, thermal mass, solar shading) and advanced energy efficiency in the specifications of building fabric, services and appliances to reduce energy demands as much as possible.
•
A central biomass CHP system connected to a district heating network to the high density part of the development (including the high density housing and commercial space).
•
Where the development is low density (below 50 dwellings per hectare), the blocks or terraces of houses would not be connected to the district network, but would be served by smaller biomass boilers.
•
The shortfall in CO2 savings would have to be met by solar PV panels installed on a high proportion of roof space.
Further work is required to investigate how a successful woodfuel supply chain can be set up to serve Whitehill Bordon. Further work will also be required to assess financial delivery mechanisms for PV to make the most of the recently announced Feed-In Tariffs. Other technologies could be integrated within the strategy but are likely to provide relatively small contributions to the overall CO2 savings required. Wind Wind turbines can provide a highly visible symbol of renewable energy and the eco-town ethos. However to function effectively a large turbine requires a large area of open land, a good wind resource, and an exclusion zone to residential properties (up to 400m for a 2MW turbine). Land surrounding turbines can be used for recreation, with some restrictions. With this in mind, the land at Standford Grange offers some potential for a wind turbine, however the wind resource here is modest and further investigation may show that it is not sufficient to make the installation of a large wind turbine cost effective. Potential effects of the turbine on the use of
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the Standford Grange land for recreation would also require careful evaluation before such a proposal could be recommended. Alternatively it may be possible to install a smaller turbine in the employment area proposed for the north of the site, where it could be a statement for sustainability visible to people entering the town from the north.
Figure 6: Possible wind turbine locations. The potential of other sites on or in the vicinity of the development can be investigated, however it should be noted that if the turbine is not on site it may not be possible to claim the CO2 savings towards achieving the zero carbon target. On the other hand, it should be possible to claim the savings for the retained element of the town. A number of more detailed studies would be required to assess the viability of wind and address any possible site constraints (e.g. monitoring of wind resource, consultation relating to aviation interference, impacts on biodiversity, noise etc.) It is worth noting that installing a wind turbine on site would reduce the requirement for installing PV but would not mean that biomass CHP can be avoided.
The following technologies have been considered but are thought to have limited potential for implementation within the Whitehill Bordon eco-town, therefore at this stage they are not part of our preferred strategy.
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Solar water heating This technology is not thought to be a realistic option as part of the new development because it competes for the same heat demand provided by biomass boilers or biomass CHP. It however presents a valuable opportunity to reduce the existing development’s CO2 emissions as a retrofit solution for the retained houses, where these have a suitable roof orientation and central heating system. Ground Source Heat Pumps (GSHPs) This technology is unlikely to play a role in the proposed energy strategy. CO2 savings are low relative to cost and proposed changes to the Building Regulations are likely to impact on demonstrable CO2 savings. Furthermore running costs for residents would rise as heat pumps are powered by electricity, which is considerably more expensive than gas. In the event that due to their location some commercial buildings cannot be connected to the district heating network, GSHPs may be a viable option. The high cooling demand of some types of commercial buildings means that the viability of GSHPs (which provide both heating and cooling) increases significantly as the technology becomes more cost effective as well as providing higher CO2 savings. Initial site investigations suggest that there is an easily accessible aquifer under the development that could be a source for open loop heat pumps. This option will only be investigated in the event that the biomass strategy outlined above cannot be brought forward. There would be very limited spatial implications from using ground source heat pumps (plant rooms to contain the pump and connections to ground loop); however this technology would only be able to provide a very small contribution to the zero carbon targets. Energy from waste Initial investigations suggest that not enough waste will be produced to make energy from waste generation via anaerobic digestion viable on site. There is however high potential for waste to be collected from the site and used for biogas generation off-site for the use of a local industry and maybe even the Eco-Town, if enough is generated. Further detail on this opportunity is provided in the waste strategy.
2.6 Options – appraised using rules of thumb Preliminary analysis was carried out to establish energy demands from the proposed development and how different masterplan scenarios would affect the energy strategy options. Given below are design and spatial implications connecting to the options considered.
AECOM
Density split 1
Irrelevant
2
High density units – 1815 Low density units – 3685 Commercial floor area 140,000
Whitehill Bordon Sustainability Strategy
Zero carbon Energy Strategy Passive design and energy efficiency of building fabric, services and appliances To be applied as a first measure to reduce energy demand, before any of the strategies below is applied
- Biomass CHP and district network for high density and commercial space - Block by block (10-20 units) biomass boilers for low density - PV panels on both high and low density development
Images
Eccleshall Biomass Power plant (photo courtesy of Eccleshall Biomass Ltd)
22
Land Take (m2)
Design Implications
Minimal increment in unit dimensions to accommodate better insulated walls Increment in space surrounding units to accommodate sun space where possible
Masterplan layout to accommodate south facing roofs as far as possible Standard unit sizes to be increased to take into account improved building fabric
N/A
- 10,000m2 for the energy centre, fuel store and space for lorry movement - 20m2 Plant room and small store for each block/terrace - 20m2 PV panels per dwelling
- High density element and commercial uses would have to be clustered together to minimise district heating pipe runs (keep cost and heat losses down) - Energy centre would have to be easily accessible by frequent large delivery trucks (probably 2 x 90m3 lorries per day) - Plant rooms in low density element would have to be accessible by smaller delivery trucks - PV will probably have to
Communal heating systems start being economically viable at densities above 60 dwellings/ha and become more energy and cost efficient the higher the density. At densities below 60 dwellings/ha block by block or individual building solutions are more appropriate. Note: different density levels will affect the cost of the solution but not the ability to achieve CO2 savings.
Cut-off
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go on both domestic and commercial roofs. Although compatible with green roofs, PV will have implications for the use of roof spaces. PV installation on roof 3
High density units – 3685 Low density units – 1815 Commercial floor area 70,000
Strategy would not change from above
- CHP engine would be slightly smaller but land take likely to remain the same (10,000m2) - PV requirement would be reduced to approximately 17m2 (but there would be less roof space available due to higher unit density)
Same as above
4
Either of above
If high density and commercial cannot be clustered together, it is possible to have small biomass CHP engines to serve 30-50 units however these would need their own fuel store and easy access. Having a lot of them dotted around the
- Each plant would need approximately 100m2.(and 6m high + a flue) - Commercial units could need one generator (and plant room) each, depending on what the use and energy demands are.
- Frequent solid fuel deliveries to each plant would significantly increase traffic - There may be noise issues with having the generators near residential development
Image of 100kWe
The size of the CHP is mainly determined by the load from the commercial element. This scenario with reduced commercial space is close to the cutoff below which doing biomass CHP is unlikely to be viable. Further investigation will determine whether it is going to be viable to reduce the CHP size further.
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site would be a less efficient use of space than a central plant. 5
Either of above
24
biomass CHP from Talbotts website (http://www.talbotts.co.uk/ BG1000leaflet.pdf)
1.5-2MW large wind turbine. This could reduce the need for PV but not significantly change the strategy outlined above
Table 5: Masterplan implications of energy strategy
Up to 400m radius exclusion zone (50ha) for a 2MW turbine. Would be less the smaller the size of turbine. Part of the exclusion zone could probably be used for SANGS or other purposes
The site should be selected based on best wind resource, but it is unlikely that a suitable location could be found on site without significantly limiting the masterplan.
A much smaller turbine (15kW) could be used and would fit more easily on site; the energy contribution would be very low, but its primary purpose would be as a statement of the town’s green credentials rather than a CO2 saving measure.
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2.7 2.7.1
2.7.2
25
Proposals and delivery implications
Proposals: • Existing buildings will be retrofitted with energy efficiency improvements and renewable energy technologies. New buildings will be designed with high energy efficiency standards, exceeding current Building Regulations requirements. •
The new high density development will be served by a biomass fuelled CHP connected to a district heating network. The energy centre will be located to the north of the development in the employment area to minimise visual impact and facilitate fuel deliveries.
•
The low density part of new development will be served by biomass boilers in individual buildings.
•
Where viable existing buildings will be connected to the district heating network.
•
Solar PV will be installed on the roofs of most buildings to generate renewable electricity.
•
A wind turbine may be installed if a suitable location is found on or off site.
Delivery implications: • Meeting the targets for a zero carbon town will have significant financial implications. Funding arrangements to deliver these targets will need to be investigated as part of the viability strategy.
2.8
•
To put things into perspective, achieving zero carbon on the new development is likely to cost £20-25k per dwelling. Ongoing work will have to ascertain whether developers will have to pay for all of this or whether suitable packages can be developed to enable home owners and or third parties to contribute. It is likely that an energy services company (ESCo) will have to be involved to deliver the zero carbon energy strategy. Furthermore other mechanisms such as eco-mortgages may be required to allow the residents to get involved.
•
An even greater challenge is presented by financing improvements for existing housing. Meeting the targets for improved energy efficiency is going to be very costly and may not be technically possible in all cases. Expecting the existing residents to pay for all of the improvements is not feasible; however it would be appropriate to expect the homeowner to contribute to a certain extent. Funding should be provided to incentivise home owners in investing in energy efficiency improvements to their homes.
•
Phasing will have an impact on how the energy strategy will be delivered.
•
Generating electricity and heat on site via a CHP system will have the practical and financial advantage that there will be no need for increasing the capacity of the existing electrical and gas infrastructure on site to serve the new dwellings.
•
Next steps The predicted energy demands from the site should be reviewed on a regular basis as the masterplan becomes more detailed to ensure that the proposed strategy is still capable of meeting the objectives.
•
Periodical review of the energy strategy should take account of any progress in the proposals for development of an anaerobic digester by Tower Brick and Tiles Ltd (see waste section for more details).
•
Once the masterplan is defined a detailed investigation should go into the potential for the installation of a wind turbine connected to the site.
•
Contact Energy Services Companies (ESCos) and enter discussions on the likely practical and financial arrangements for delivering and managing the district heating
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system. It may also be possible to enter discussions with ESCos regarding delivery of extensive amounts of solar PV finding ways of taking advantage of Feed-In Tariffs. •
Development briefs should require developers to install energy monitoring systems and EHDC should set up a suitable mechanisms to collect and analyse the data. Monitoring and analysing energy data can be the first step towards eventually calculating and monitoring the town’s carbon footprint.
•
Detailed utility studies will have to be carried out for the individual development packages to ensure that there are no existing constraints to the delivery of the final energy strategy.
Waste Strategy
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3 Waste strategy
3.1 Waste strategy Objectives High level objectives have been formed for the waste management strategy for Whitehill Bordon following a review of: the Green Town Vision, Eco-towns Planning Policy Statement, local and regional planning and waste policy, the Eco-towns Waste Worksheet2 and initial review of waste treatment options for the site. The objectives are as follows: •
Towards zero waste to landfill – with effort focused on waste minimisation and re-use;
•
View waste as a resource – recover value from waste generated within Whitehill Bordon and the local wider community;
•
Closed-loop system – aim for waste generated on site to be treated on site;
•
Co-management of municipal, commercial and industrial waste – seek to achieve coordinated waste management for all uses on site, so the aim of towards zero waste extends to commercial and industrial waste;
•
Behaviour change – work towards a cultural change such that the waste hierarchy (reduce, reuse, recycle) principles are embedded in all aspects of life and work and there is a real ownership of waste; and
•
Average annual waste growth per capita in Whitehill Bordon to be 0.5% compared to the UK annual average increase in waste arisings of 2.5%.
3.2 Existing waste management arrangements and facilities An initial review has been undertaken to establish how waste is currently managed in the Whitehill Bordon area. Key findings are set out below: Domestic waste Domestic waste in East Hampshire is managed through “Project Integra”3 which is an integrated waste management strategy adopted by the 14 district councils of Hampshire; Hampshire County Council; and the private waste contractor Veolia. A review of the Integra website and discussions with East Hampshire District Council reveals that domestic waste in the Whitehill Bordon area is currently managed as follows:
2
3
•
Paper and cardboard; cans; and plastic bottles are collected fortnightly via kerbside collection. These wastes are taken to the Alton Materials Recovery Facility (MRF) (discussed further below). Materials here are sorted, bulked and bailed and then sent on for reprocessing elsewhere in the UK or overseas, wherever there is the demand or market;
•
Glass - is collected from the kerbside every 4 weeks and is taken to Basingstoke as there is currently no storage facility at Alton. There are however plans to retrofit the Alton MRF to accept glass;
•
Residual waste is collected from the kerbside on alternative weeks from the recyclables and is taken to the Energy from Waste (EfW) facility in Portsmouth. Hampshire has a total of three energy from waste facilities the other two being Chineham, near Basingstoke and Marchwood, near Southampton. Together they are reported to
http://www.tcpa.org.uk/press_files/pressreleases_2008/20081202_ET_Waste.pdf http://www.integra.org.uk
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process 420,000 tonnes of waste each year, generating enough electricity to power 37,000 homes4; •
Green waste - EHDC offers a fortnightly garden waste collection service for an annual charge of £25.00 for the first licence (and £12.50 for any subsequent licences). There are three composting sites within Hampshire: Chilbolton (south of Andover); Down End (Fareham); and Little Bushy Warren (Basingstoke). Discussion with EHDC indicated that Hampshire is not strongly in favour of collection of green waste due to distances it has to be transported. They are however supportive of home composting.
Alton Materials Recovery Facility The Alton MRF opened in 2004 and is reported to be one of the most advanced in Europe5. Newspapers, magazines, plastic bottles, tins and cans are collected. These materials are segregated, baled up and sent to private companies for recycling. As stated above there are plans to retrofit Alton to cater for glass collection. Initial discussions with the Alton MRF site manager and EHDC indicates that recyclable waste from Whitehill Bordon Eco-town would be sent to the Alton MRF, which has capacity to take the recyclables. This will require agreement with Hampshire County Council. Household Waste Recycling Centre There is an existing household waste recycling centre (HWRC) located on Station Road, which takes the following wastes: glass; cans and metal; clothes; paper; car; furniture; oil; fridges and freezers; green waste and plastic bottles. Commercial / Industrial waste Trade refuse collections are not provided as part of the Council Tax or National Non-Domestic Rates in Hampshire. Businesses and commercial organisations are responsible for arranging proper disposal of their waste under Defra's Duty of Care. Contact details are provided on EHDC website of local commercial refuse collection companies. Waste water The Bordon Sewage Treatment Works (STW) is located just north of Bordon, between the A325 and the village of Lindford. The sludge produced during the treatment process is currently being transported by road to the Farnham Sewage Works. Thames Water, who runs the site, predicts that the facilities will have to be extended to accommodate the increase in population from the Eco-Town. It is currently thought that there is sufficient space on site to increase capacity without requiring a new site, however this can only be confirmed at a later stage. A foul water pumping station is located slightly to the west of the Louisburg Barracks to the north of the playing fields. This pumping station will have to be retained.
3.3 Likely waste arisings The predicted waste arisings for all land uses in Whitehill Bordon have been estimated for the anticipated operational year of 2023. These estimates have been made assuming a maximum of 5500 new dwellings and 7000 jobs and an annual increase in waste of 2.5% a year up to 2023; this is detailed in Table 6 below.
4 5
http://www.integra.org.uk/ERF.html http://www.veolia-finance.com/press-release-73.html
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Totals for all Land uses
2023 Tonnes/ year for all uses
Waste stream Paper and card
6,658
Glass
650
Metal
685
Plastics
1,830
Organics
3,929
Other
2,096
Total
15,847
Table 6: Whitehill Bordon predicted waste arisings for all land uses (2023) The total predicted waste arisings for Whitehill Bordon is 15,847 tonnes / year of which approximately 70% is estimated to arise from domestic uses. The strategy to date has therefore focused on domestic waste. As information on the expected non-domestic uses becomes available the waste strategy will be expanded to address commercial and industrial waste. The breakdown of the predicted waste arisings by waste type is illustrated by Figure 7 below:
Other 13% Paper and card 42%
Organics 25%
Plastics 12%
Glass 4% Metal 4%
Figure 7: Whitehill Bordon predicted waste arisings (%) for all land uses (2023) 3.4 Options - appraised using the rules of thumb For the purposes of the Whitehill Bordon Eco-town waste management will be considered in the following five stages: •
Storage – both in individual households and communally prior to collection;
•
Collection – from the place of production/storage to a central location;
•
Transfer – of collected wastes delivered to the central location for further processing or treatment;
•
Treatment – e.g. sorting of materials at a material recovery facility, gasification, anaerobic digestion, incineration, etc;
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•
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Final disposal – of non-recyclable elements of the waste streams or by products of above treatment stages to landfill.
It should be noted that some technologies straddle a number of these stages. For example, a vacuum collection system would cover aspects of storage, collection and transfer of wastes. To date the waste management strategy has focused on reviewing the treatment stage. This is because treatment options tend to have the largest space implications, which need to be considered in the developing masterplan. Consideration has also been given to those elements of waste collection and transfer that have space implications. Detailed consideration has not been given to the final disposal stage as this is assumed to be dealt with offsite. The aim of the strategy will be to reduce as far as possible the level of waste that requires final disposal. The options that have been appraised for the site together with advantages and disadvantages are set out in Table 7 at the end of this section. A summary of the key waste management options for Whitehill Bordon are presented below: Storage Temporary storage of wastes both internally and externally to buildings is required prior to waste being collected. Further consideration will be given to the storage requirements at detailed design stage and minimum provisions would be outlined in any development briefs or design guides provided to developers to ensure ease of segregation into the four waste streams collected by the in East Hampshire. The minimum space requirements for waste streams will need to be in line with the Code for Sustainable Homes (CSH) for domestic buildings and with BREEAM requirements for the commercial and industrial buildings. Collection The options for collection of waste are as follows: •
Vacuum collection system;
•
Road-based collection;
•
Food waste disposers, i.e. collection of food via a macerator built into the kitchen sink and linked to the foul water system.
The system currently favoured for Whitehill Bordon is road collection due to the associated lower energy intensity of this option and the compatibility with existing waste collection systems in the area. Transfer The conventional method of waste transfer is by road, using heavy vehicles. This is the method currently used by Hampshire County Council and it is expected to remain the case in future. Transfer of recyclable and residual waste is anticipated to be direct to a treatment facility off site. There may be opportunity to use a rail link to transfer waste, however this would only be worth considering if the rail line could be designed to connect the treatment facility to the site. The impact of transfer to treatment facilities on and off site could potentially be reduced with the implementation of electric or biofuel powered vehicles. Treatment The preferred treatment option for each of the waste streams generated on site are illustrated by Figure 8 and is followed by a brief discussion of each option.
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Energy from Waste mostly incinerated
Recycled – Alton Materials Recovery Facility
Other 13%
Composting - on site and / or locally
Paper and card 42%
Organics 25%
Anaerobic digestion - close to site Plastics 12%
Glass 4% Metal 4%
Recycled – Alton MRF
Recycled – Alton MRF
Figure 8: Whitehill Bordon predicted waste arisings (%) for all land uses (2023) and preferred treatment options Materials Recovery Facility It is intended that recyclable wastes will be treated by the Alton MRF, which is approximately 15 km by road from the existing Bordon town centre. Given that initial research indicates that the Alton MRF has capacity and is in close proximity to Whitehill Bordon, it is not considered that an additional new MRF is required for the Eco-town. Composting Within the low density areas of Whitehill Bordon home composting of garden and food waste by residents will be encouraged, therefore avoiding the need for transfer. A central composting facility is also proposed to treat within the town the green and food waste from buildings that do not have the space to accommodate individual compost bins. The compost generated would then be used on site for landscaping or be sold to local gardeners. In addition to the organic waste arisings predicted above there is likely to be seasonal generation of landscaping green waste, which would also be treated on site through compositing. Anaerobic digestion Anaerobic digestion is an effective way of dealing with organic food waste with the added advantage of generating energy through the process (in the form of biogas). Initial investigations suggest that Whitehill Bordon will not generate sufficient food waste to make the installation of an anaerobic digester economically viable, however some opportunities are available for diverting the food waste from the town that cannot be composted at point of use to be digested off site. Local brickworks supplier Tower Brick and Tiles Ltd (TBT) have expressed interest in taking the food waste generated by Whitehill Bordon. TBT are putting together proposals to develop a biogas digester at their brickworks (which is located 3.3 miles from the existing Bordon town centre) and use the biogas to fire their kilns. Whilst the intention is to develop this facility within the next two years, before any substantial development is likely to take place at Whitehill
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Bordon, TBT intend to take 3500 tonnes of kitchen waste a year from Waverley, Surrey. The circa 2000 tonnes / year of waste from Whitehill Bordon would be a more local source of waste for this facility. TBT have plans to extend their operations in the future and have expressed an interest in obtaining additional biogas supplies to match their anticipated growth. If the anaerobic digester taken forward by TBT is of sufficient size, there may even be opportunity for biogas to be used as a low carbon fuel source to the Eco-Town; however the viability and benefit of this can only be assessed at a later stage when both the masterplan and TBT’s proposals will be better defined. Food wastes and slurry are compatible materials for treatment in a biogas digester giving potential for collaboration with the wider local farming community. In addition the fertiliser and soil improver produced could provide benefit to the local farming community. Initial discussion with neighbouring Blackmoor Estates confirms that they currently produce roughly 5000 tonnes of cow slurry a year and are considering anaerobic digestion as means to treat this waste. The Estate may be interested in receiving food waste from the town to increase their biogas yield and energy generation. Another opportunity that will need to be investigated at a later stage would be to transfer the food waste to the town’s sewage treatment works via food disposal units. Here the waste could be digested together with the sludge generated from the sewage treatment process. The potential of this option will have to be discussed with Thames Water, who runs the Bordon Sewage Treatment Works, at a more detailed design stage In any case it is predicted that any energy generated from the biogas would be fed back into the sewage treatment and AD process.
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Waste type/s
a
Vacuum collection systems
All excluding: - glass; and - cardboard - bulky items
b
Road collection
All
c
Food waste disposers
Food
d
Materials Recovery Facility
All
e
AD plant - Scale 1 processes WB waste only
f
AD plant - Scale 2 commercial scale accepting waste from off site.
- The biodegradable element of waste generated from on site plus off site waste from Hampshire - Potential to supplement with sewage sludge (not investigated here) - Potential to supplement with slurry from neighbouring farms The biodegradable element of generated waste.
Treatment
Transfer
Collection
On site options Technology
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Space requirement (approx) Terminal station footprint approx. 800 square metres
Internal and external waste storage requirements N/A
Not investigated due to close proximity of the Alton MRF Approx. 7,500 square metres
Approx. 20,000+ square metres
Advantages
Disadvantages
- Eliminates on street bins and creates clean and tidy streetscape - Reduces need for storage space inside residences - Incumbent system in Hampshire and therefore well tested - Very flexible and easy to extend to new areas of development - Ready made transport mechanism - Reduces need for storage space inside residences - An on site MRF could provide jobs on site.
- Large energy requirement - Requires education of users and risk of malfunction due to improper use - Not suited to all waste streams - Results in increased heavy traffic on roadways - Potentially noisy and dirty operations - Potentially energy and water intensive. - Perceived risks of blockages and odours - Unlikely to be required as service provision would be provided by local authority using Alton MRF.
- Local closed loop - i.e. waste generated on site treated on site - Produces biogas which could feed into energy strategy - The digestate can be separated into a solid soil conditioner and a liquid fertiliser use for local farmers - Job creation
- Possible community resistance - Additional collection arrangements for biodegradable waste - Not enough waste generated to be economically viable
- Economical in terms of scale - Potential surplus energy to feed site or biogas of interest to local brickworks - Local job creation
- Site space required - Possible community resistance - Additional collection arrangements needed for biodegradable waste
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g
Sewage Treatment Works on site
Food waste
TBC
h
Gasification plant - Scale 1 processes WB waste only
Approx. 10,000 square metres
j
Gasification plant - Scale 2 commercial scale accepting waste from off site.
Process residual waste (i.e. should seek to remove all recyclables in line with waste hierarchy) but potentially could be extended to all waste. All
k
Composting - windrow on site - Scale 1 processes WB waste only
l
Composting - windrow on site - Scale 2 commercial scale accepting waste from off site.
Green waste / garden derived waste / landscaping waste (grass clippings etc)
Green waste / garden derived waste / agricultural waste
Local closed loop - i.e. waste generated on site treated on site - Potentially could be met by extension of the existing Bordon STW - Local closed loop - Feed syngas to local energy centre
- Site space required - Possible community resistance - Additional collection arrangements for biodegradable waste
Approx. 20,000+ square metres
- Economical in terms of scale - Feed syngas to local energy centre - Job creation
From approx 4000 square metres excluding potentially landscaping waste.
- Local closed loop for this waste stream - Jobs on site - Compost demand by fruit farms and other agricultural uses in the local area.
- Too small to be economically viable - Possible community resistance - If recyclable wastes not removed would not be in line with the waste hierarchy. - Home composting by residents will be recommended in the low density areas, potentially reducing green waste supply on site - Potential environmental issues associated with composting are odours, noise and leachate control - Possible community resistance.
NOTE: Landscaping wastes arisings not included in this calculation. Approx 15,000 square meters (limited only by space and waste availability).
-
- Jobs on site - Compost demand by fruit farms and other agricultural uses in the local area
- Too small to be economically viable - Possible community resistance - If recyclable wastes not removed would not be in line with the waste hierarchy.
- Discussion with EHDC detailed that take up of green waste collection has not been strong in the district - Environmental issues and possible community resistance
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m
n
Composting - in vessel on site - Scale 1 processes WB waste only.
Composting - in vessel on site - Scale 2 commercial scale accepting waste from off site.
Off-site Treatment
Off site solutions o Composting
Garden, kitchen, and organic waste (can include cardboard and meat related kitchen waste)
Garden, kitchen, and organic waste (can include cardboard and meat related kitchen waste)
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From approx 4000 square metres excluding potentially landscaping waste. NOTE: Landscaping wastes arisings not included in this calculation. Approx 15,000 square meters (limited only by space and waste availability).
- Less space intensive than windrow - Lower risk of potential environmental issues - Jobs on site - Compost demand by agricultural uses in the local area
- Animal By-products Regulation issues if all kitchen waste accepted - Still residual environmental issues will require consideration - Possible community resistance.
-
- Discussion with EHDC detailed that take up of green waste collection has not been strong in the district - Environmental issues and possible community resistance
Less space intensive than windrow - Lower risk of potential environmental issues - Jobs on site - Compost demand by agricultural uses in the local area
Garden, kitchen, and organic waste (can include cardboard and meat related kitchen waste)
n/a
- No spatial implications on masterplan - No community resistance
Not closed loop
p
AD
Food waste and/or sewage sludge and/or slurry.
n/a
- No spatial implications on masterplan - No community resistance
Not closed loop
q
Alton MRF
All domestic waste excluding glass and green waste.
n/a
- Alton MRF has capacity - Local treatment - Compatible with existing waste collection
Further investigation is required to assess where the commercial waste would be treated.
Table 7: Whitehill Bordon Waste Management Option Appraisal
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3.5 3.5.1
3.5.2
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Proposals and delivery implications
Proposals • Dry recyclables will be taken to the Alton MRF facility for sorting and recycling. •
Transfer of waste will be by road, with electric or biofuel powered vehicles.
•
Organic waste will be composted at source wherever possible (i.e. houses, flats and businesses with sufficient outdoor space).
•
Food waste that cannot be composted at source will be digested off site. It will be used either by neighbouring businesses with digesters for energy generation, or transferred to the sewage treatment works via food disposal units for co-digestion with sewage sludge. This would generate energy to feed back into the STW process, which would reduce the CO2 emissions associated with water treatment.
•
Green waste not composted at point of use will be composted in a central facility located to the north of the site. The compost generated will be used for landscaping purposes in the area or sold to local gardeners.
•
Residual waste that cannot be recycled or treated on site will be reduced by a series of behavioural change campaigns tackling recycling uptake and consumer choices (e.g. grow your own food, shop at the farmers’ market rather than the supermarket etc.). Any remaining residual waste will be taken to the energy from waste facility to generate electricity.
Delivery Implications • Crucial to delivery of the waste management strategy on site will be agreement with HCC and EHDC.
3.6
•
Achieving the co-management of municipal, commercial and industrial waste is necessary to ensure the objectives identified above are not only met by the residential element of the scheme.
•
Incentive schemes and education of the site users is necessary to achieve behaviour change. This way waste generation will be reduced and waste will be treated as a resource. Furthermore people will feel ownership and responsibility for their waste.
•
Next steps Once the masterplan is defined the design team will have to enter discussions with the waste management departments of HCC and EHDC to ensure that any proposals for onsite treatment fit well with the Council’s waste management plans.
•
As the design progresses the design team should keep contact with Tower Brick and Tiles Ltd to ensure that any opportunities for waste management and potentially energy generation are pursued. TBT are currently developing an anaerobic digester on their site and could potentially take organic waste from the Eco-Town and maybe even provide the town with energy from waste.
•
Once the masterplan is defined HCC and EHDC should enter discussions with Thames Water to assess the viability of introducing food waste disposers to the development therefore treating food waste via the sewage treatment work process and co-digestion.
•
EHDC and HCC should investigate a way to ensure that commercial waste management in the town works towards achieving the same targets as domestic waste. This could be done by providing a centralised advice centre to guide commercial waste generators towards waste management techniques that complement the domestic waste strategy. Alternatively the Council could enter in partnership with a private commercial waste management company to ensure that they are the preferred service provider by local businesses and that their methods are in line with the Council’s aspirations.
Climate Change Adaptation
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4 Climate Change Adaptation
4.1 Climate change adaptation objectives The following objectives have been identified for climate change adaptation at Whitehill Bordon. They are taken from the Green Town Vision and current planning policy applicable to the location and to Eco-towns. Although it does not refer to climate change adaptation directly, the Green Town Vision includes the following targets for the site, which would contribute to building adaptive capacity: •
All Special Protection Areas will be protected and risk to them will be mitigated by providing Suitable Alternative Natural Green Spaces
•
Land will be set aside for new public open space
•
40% of the town will be green space, including public and private realms
•
Water neutrality – the new town will not exceed current water usage
The Eco-towns PPS includes requirements for developments to be built that are resilient to a changing climate, taking into account landform, layout, building orientation, massing, avoidance of solar gain in the summer (PPS1 supplement on Planning and Climate Change) – and taking into account the risk of flooding (PPS25). As a general requirement, it states that: “Developments should be designed to take account of the climate they are likely to experience, using, for example, the most recent climate change scenarios available from the UK Climate Change Impacts Programme. Eco-towns should deliver a high quality local environment and meet the standards on water, flooding, green infrastructure and biodiversity set out in this PPS, taking into account a changing climate for these, as well incorporating wider best practice on tackling overheating and impacts of a changing climate for the natural and built environment.” The Eco-towns PPS provides further detail on policy in several areas relevant to climate change adaptation, as set out in Table 8.
Policy Area Flooding
Water Green infrastructure
Requirements Eco-towns should not increase the risk of flooding elsewhere and should use opportunities to address and reduce existing flooding problems. Where possible the built-up areas of an eco-town (including housing, other public buildings and infrastructure should be fully within Flood Zone 1 - the lowest risk. Flood Zone 2 areas can serve as open spaces and informal recreational areas whilst there should be no built-up development in Flood Zone 3, with the exception of water-compatible development and, where absolutely necessary, essential infrastructure). Eco-towns should: • Incorporate the measures in the water cycle study for improving water quality and managing surface water to prevent surface water flooding; and • Incorporate sustainable drainage systems (SuDS) and, except where this is not feasible, as identified within a relevant Surface Water Management Plan, avoid connection of surface water run-off into sewers. Eco-towns in areas of serious water stress should aspire to water neutrality, i.e. achieving development without increasing overall water use across a wider area. 40% of the eco-town’s total area should be allocated to green space, of which at least half should be public and consist of a network of well managed, high quality green/open spaces which are linked to the wider countryside.
Table 8: Eco-town planning policy requirements for issues related to climate change adaptation The draft South East Plan contains a policy (CC2) on climate change. In respect of adaptation it states:
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“Adaptation to risks and opportunities will be achieved through: •
Guiding strategic development to locations offering greater protection from impacts such as flooding, erosion, storms, water shortages and subsidence;
•
Ensuring new and existing building stock is more resilient to climate change impacts;
•
Incorporating sustainable drainage measures and high standards of water efficiency in new and existing building stock;
•
Increasing flood storage capacity and developing sustainable new water resources;
•
Ensuring that opportunities and options for sustainable flood management and migration of habitats and species are not foreclosed.”
Full details of the risks and implications of climate change that are behind the above targets can be found in Appendix A.
4.2 Climate change adaptation options A number of adaptation options are described below. There is a focus on measures which require consideration at the masterplanning stage, though some attention is given to detailed design issues such as building form and orientation too. 4.2.1
Green roofs and other permeable surfaces In addition to improving drainage and reducing run-off, green roofs and other permeable surfaces play an important role in managing high air temperatures. This is due to the cooling effect caused by evaporation of water absorbed by the surface and evapo-transpiration by living plants. Research into ways of preparing for climate change through strategic planning and urban design has been conducted for the ASCCUE project, using Greater Manchester as a case study. A key finding of this study was that maximum surface temperatures in high density urban areas were 12.8oC higher than in town parks, and 6.2oC higher than in low density urban areas. This difference, an example of the urban heat island (UHI) effect, is expected to be exacerbated by climate change. This effect was found to be linked to the proportion of permeable surface area, which in the study was assumed to be around 31% in high density urban areas and 66% in low density urban areas. Increasing the area of permeable surface in high density areas using trees, green roofs and permeable paving was found to have a cooling effect, with the potential to maintain temperatures at or below current levels for all future emissions scenarios. Reducing green space on the other had a significant impact and left urban areas vulnerable to overheating. A similar but less pronounced effect can be seen with rates of water run-off. To provide sufficient adaptive capacity to maintain internal and external temperatures at today’s levels across all UKCIP climate scenarios up to the 2080s, the following threshold is recommended for the site: Adaptation objective Maintain thermal comfort
Threshold 66% of the surface area of each development plot should be permeable to water
The cooling effect of permeable surfaces can be achieved by including dedicated green or blue open space, or by integrating them with buildings or paved areas. A hierarchy of available options for achieving the threshold area is shown below (Figure 9); surfaces at the top generally have a higher permeability and greater spatial implications than those at the bottom. It is important to apply this hierarchy at the optioneering stage to ensure maximum adaptive capacity is targeted. However, a degree of flexibility is also required to ensure that greater adaptive capacity can be achieved over time.
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Green and blue open spaces Increasing spatial implications
Pocket parks, gardens and SUDs
Tree-lined avenues
Green roofs
Green walls and permeable paving
Figure 9: Hierarchy of permeable surfaces The diagram does not necessarily indicate which measure is most suited to managing high temperatures or surface water run-off, though there is a degree of correlation with permeability. Generally, green roofs and green walls are more suited to higher densities, where available space is marginal. In addition to providing effective cooling through evapo-transpiration, tree-lined avenues provide shaded connectivity, protection from high winds and wider benefits for biodiversity and the character of the public realm. The wider advantages and disadvantages of each option should be considered against the specific location that the measure is proposed for. Integration with other adaptive measures should also be considered. The corresponding area of permeable surface required in each development site is shown in Table 9. Site 1 2 3 4 5a 5b 6
Quebec Barracks Community Centre Playing Fields Prince Philip Barracks Technical Area The Croft (Hogmoor) Hogmoor Inclosure Total: Development:
7a 7b 9 11 12a 12b
Louisberg Barracks Louisberg Playing Fields Cricket Ground Sewage Works Area HCC Land Eveley Wood
Table 9: Permeable surface area required
Total area (ha) 3.4 2 12.3 15.3 36.6 7.2
Permeable area (ha) 2.24 1.32 8.12 10.10 24.16 4.75
66.7 10.47 21.2 5.7 24.4 22.4 45.7 13.6
6.91 14.00 3.76 16.10 14.78 30.16 8.98
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An illustration of how this proportion of permeable surface area could be achieved in low and high density areas is provided in Figure 10.
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Figure 10: Illustration of high proportion of permeable surfaces in low and high density areas 4.2.2
Sustainable Drainage Systems (SuDS) SuDS can be incorporated to collect run-off water, providing temporary storage and enhancing infiltration into the ground. In addition to reducing flood risk, they can help to replenish groundwater levels and improve water quality by trapping and breaking down pollutants. Effective design of SuDS can also provide amenity benefits and passive cooling. The opportunities and constraints associated with SuDS are detailed in the water cycle study carried out by Halcrow. The inclusion of a high proportion of permeable surfaces, as described in the previous section, will contribute to source control of run-off flows. An initial assessment has been made of the SuDS storage volumes required for site control in each development site. The calculation was undertaken for several levels of surface permeability. The figures summarised in Table 10 assume an average of 66% of the surface area in each site is permeable to water, as recommended above. The storage volumes would be required in addition to any attenuation provided by green roofs, permeable paving, parks and gardens and other green or blue space already accounted for. The storage volumes have been increased by 30% to allow for the effects of climate change on rainfall duration and intensity, as per the requirements of PPS25. Initial estimates in the water cycle study indicate that 15% of the development areas (either within each development area or green corridors in the vicinity of the developments) need to be reserved for wetlands, swales, ponds, infiltration basins, etc. This is to ensure that sufficient space is allocated for attenuation storage and/or infiltration to greenfield runoff. The water cycle study recognises the importance of ‘green SuDS’, stating they are the preferred approach compared to hard engineered infiltration systems. However, it is necessary to ensure sufficient adaptive capacity across the site. In order to meet the shortfall between 15% and 66% permeability other green infrastructure should be incorporated.
Site 1 2 3 4 5a 5b 6
Quebec Barracks Community Centre Playing Fields Prince Philip Barracks Technical Area The Croft (Hogmoor) Hogmoor Inclosure
7a 7b 9 11 12a 12b
Total: Development: Louisberg Barracks Louisberg Playing Fields Cricket Ground Sewage Works Area HCC Land Eveley Wood
Total storage volume (m3) 230 135 1,930 1,145 3,080 1,125
Total land take, assuming 1.5m depth (m2) 153 90 1,287 763 2,053 750
1,640 1,605 890 3,810 3,035 6,230 -
1,093 1,070 593 2,540 2,023 4,153 -
Table 10: SuDS storage volumes Figure 11 shows suitable locations for SuDS features to provide the storage volumes quoted above, based on the direction of the fall of the land in each sub-catchment area. The locations are flexible, provided that the land falls in the correct direction. The map also provides figures for storage volumes corresponding to surface permeability values of 25% - 45%, which are more typical of medium to high density developments. The map shows the site control features as ponds, however alternative configurations are available which may provide a better fit with other masterplan objectives including the proposals for landscaping.
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Figure 11: Illustration of potential SuDS features
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It is understood that much of the site has permeable soil which is suitable for infiltration. However, the design of the SuDS features will need to take into account potential risks to water quality associated with ground contamination, particularly as the local water supply depends on abstraction of water from the underlying aquifers. Initial advice from Halcrow indicates that infiltration may not be possible in the zone surrounding the St Lucia MoD borehole and the Quebec artisan well. Infiltration SuDS for highway and parking areas usually require additional safeguards such as seal-trapped gullies or oil/grit separators and the use of borehole soakaways will require Environment Agency agreement. 4.2.3
Avoiding Development on Flood Plains Where possible the built-up areas of the eco-town (including housing, other public buildings and infrastructure) should be fully within Flood Zone 1 ( the lowest risk). Flood Zone 2 areas can serve as open spaces and informal recreational areas whilst there should be no built-up development in Flood Zone 3, with the exception of water-compatible development and, where absolutely necessary, essential infrastructure. The Strategic Flood Risk Assessment for East Hampshire notes that “Fluvial floodplains run along the west and east borders of Bordon and Whitehill – development so far has largely allowed space for this so further development should avoid encroaching on the floodplain. There have been some incidents of groundwater flooding and the groundwater emergence maps indicate a risk of groundwater flooding.” The following map (Figure 12), extracted from the Strategic Flood Risk Assessment, highlights the flood risk zones identified in the Whitehill Bordon area.
4.2.4
Designing for Water Efficiency Whitehill Bordon is located in the region served by South East Water, which has been classified by the Environment Agency as an area of serious water stress. South East Water’s web site states that better use needs to be made of existing water sources and new sources need to be developed, or there is a risk of a shortfall in water availability by 2015/16. This shortfall could be exacerbated by climate change, as the predicted hotter, drier summers could result in increasing demand for water and more frequent droughts. The existing water supply for the town is entirely from local groundwater sources. Increasing the density of development of the site could lead to increased water stress without intervention. However, it is understood that a well and borehole currently used by the MoD, together with improved water efficiency in the existing town, could supply sufficient water for the new development. The Green Town Vision sets a target of water neutrality for Whitehill Bordon, which it defines as water use in the future town being no greater than current levels. Achieving this target will require water efficiency to be designed into the built environment and the landscaping and management plans. Both greywater recycling and rainwater harvesting will be required, with some (sub-surface) space required for storage. In the case of rainwater harvesting, this can be compatible with SuDS. The type of tree or other green infrastructure that is planted should be suited to the local conditions and they should not require artificial irrigation beyond their initial stages of development. Putting the right tree in the right place is imperative to ensure ongoing adaptive benefit; it is also important to ensure that the right buildings and spaces are designed and built to accommodate them for the longer term.
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Figure 12: Strategic Flood Risk Assessment map for Whitehill Bordon 4.2.5
Managing the Impacts on Ground Stability The geology and hydrogeology of the proposed development sites has been reviewed, using available British Geological Survey (BGS) mapping data. The following sequence of drift and solid strata was identified:
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Alluvium Head Deposits
Drift deposits
River Terrace Deposits Folkestone Formation (Lower Greensand Group) Sandgate Formation (Lower Greensand Group)
Solid deposits
The 1:50,000 scale BGS geological mapping notes the Folkestone Formation to comprise fine to coarse grained sands and weakly cemented Sandstone. The Sandgate Formation comprises a number of more variable units with sand and sandstone members as well as mudstone and siltstone members. Generally solid deposits outcrop below most study areas, with only two areas to the east, namely the HCC plot of land (Area 12b) and the MoD Greenfield land (Area 11) underlain by Drift Deposits. The study area lies on two major aquifers, which can contain a significant quantity of groundwater for abstraction. These are the Folkestone Formation and the River Terrace Deposits, where it overlies permeable Folkestone Formation and Sandgate Formation strata. In relation to ground stability, the main risks lie some distance beyond the eastern boundary of the potential development sites, where historical instability is noted on the BGS mapping. Within the northernmost part of the study area the mapping indicates one area (Area 11) with limited Head Deposits that appear to follow dry valley alignments. These strata may be cohesive and susceptible to moisture content change, however their extent is limited and the general topography does not suggest steep slopes. The study areas are considered to be at a low risk of significant and widespread ground stability issues as a result of climate change. Future work may be required to confirm ground stability conditions, including borehole sampling. This is currently assumed to be beyond the scope of the masterplanning process, but may need to be undertaken in support of future development of specific sites.
4.2.6
Building Design It is important to ensure that buildings are of an appropriate thermal mass for the intended use and that potential for natural ventilation, vegetation and water drainage are maximised. Building materials, window size, building orientation, the use of narrow plan (encouraging natural ventilation) and solar protection (internal or external shading) are important measures which can be combined to help control the internal temperature of a building. Buildings aligned correctly (road width, height of building) can reduce the possibility of wind tunnels but encourage a gentle cooling breeze. Developments which rely mainly on natural ventilation may not be suitable along roads with heavy traffic. These adaptive measures do not have major spatial implications for the masterplan, but should be considered when developing examples of typical building and place typologies. It will be important to include more detailed requirements in any design codes that are developed in the future.
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Figure 13: Building Design: Examples of external shading6
4.3 4.3.1
4.3.2
Proposals and delivery implications
Proposals: • 66% of the surface area of each development site should be permeable to water. Permeable surfaces should be relatively evenly distributed across each development site, as the cooling effect is most effective on a micro-scale. •
Appropriate use of adaptation options described in Appendix A to minimise the identified climate risks.
•
Incorporate SuDS features to provide the recommended storage volumes as a minimum.
•
Avoid development in the flood risk areas shown.
•
Design water efficiency into the built environment and landscaping, including the existing town. This will be achieved by installing water efficient sanitary ware in new buildings and retrofitting water saving measures in existing buildings. White goods should be specified to be water efficient and greywater recycling systems will be designed into new buildings to reduce internal water use. Rainwater collection will be provided to all buildings to ensure that rainwater is used instead of potable water for low grade external uses such as irrigation.
•
Assess localised risk following ground investigations. In areas where a stability risk is identified: - Strengthen retaining structures - Use flexible construction - Use SuDS and other methods of soil moisture control - Use vegetation to stabilise slopes - Re-grade land if landslip is an issue
Delivery implications • The recommendations given above will have to be reviewed as the masterplan becomes more detailed and they will have to be introduced as requirements in development briefs to ensure that they are not ignored at detailed design stage. 6
Image description (clockwise): Chiswick Park, London © David J Osborn, External shading on the façade of buildings. Shaded balconies which increase the amount of private space where private gardens are not available. Retrofitted external shading. Rich Mix Cinema, East London. Shutters might be appropriate for residential units.
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4.4
•
49
Next steps The design team should periodically review the masterplan as more detail is introduced to ensure that the target level of permeable surface is maintained.
•
Once the masterplan is defined, a detailed SuDS study should be carried out to determine the most appropriate SuDS techniques to be used across the site. At the moment the storage volumes are only shown as ponds but it is likely that better ways of integrating SuDS can be found following a detailed assessment.
•
Commission a detailed water strategy to ensure that the opportunities and constraints highlighted in the Halcrow Outline Water Cycle Study become effective measures and develop hand in hand with the masterplan.
Conclusions
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5 Conclusions
5.1 Energy New buildings (both domestic and non-domestic) will be designed to have energy efficient envelopes and, where appliances are provided, these will be specified to have low energy consumption (e.g. A+ rated fridges, washing machines etc.). These measures will ensure that the energy demand associated with the new buildings is reduced compared to standard buildings. The new buildings in the high density areas of the masterplan will be heated by a district heating system powered by a biomass fuelled combined heat and power (CHP) engine. As well as heat, the engine will produce electricity that will be used locally, therefore avoiding the high distribution losses associated with the standard approach of centralised electricity generation. It is proposed that the energy centre will be located in the employment area to the north of the site, therefore reducing visual impact and facilitating access for fuel delivery. The system will be managed by an Energy Services Company (ESCo), who will be responsible for operation, maintenance and billing arrangements. In low density areas, where it is not financially viable to extend the district heating network, biomass boilers will be used for heating individual buildings. In order to meet the zero carbon definition stated in the Eco-Towns PPS, the district heating system will be supplemented by the installation of solar photovoltaic panels (PV) on the roof of most buildings to generate renewable electricity. The existing buildings in Whitehill Bordon that will be retained will also benefit with the introduction of a series of retrofitting measures to improve their energy performance and reduce their running costs. Connecting existing buildings to the proposed district heating network is going to be very costly and unlikely to be viable in most cases, however this option will be considered for buildings where it is likely to be cost effective. Preliminary investigations suggest that there may be the potential to install a medium size wind turbine on site to boost the on-site renewable energy generation and reduce the need for PV panels, which have a higher capital cost. The Hampshire County Council land to the south of Lindford village is the only area sufficiently free from buildings to be suitable for a large wind turbine (2MW, 120m high to the tip). The employment area proposed to the north of the site may however accommodate a small/medium turbine, depending on the detailed layout of the area.
5.2 Waste In order to make it easy for Whitehill Bordon’s inhabitants to dispose of waste in the most effective way, all new buildings will be provided with suitable facilities for the storage of waste at point of generation. Homes will be provided with internal and external bins for segregating different waste streams, non-domestic buildings will also be provided with sufficient space to accommodate waste segregation. All houses with garden will be provided with compost bins so that organic waste (i.e. food and garden waste) can be disposed of where it is generated without needing to be transported elsewhere. Flats and non-domestic buildings will also be provided with the space for storing organic waste, although it is predicted that the waste will have to be treated elsewhere. The household waste recycling centre will be relocated in the employment area to the north of the site and it will be extended to include a facility for exchanging and possibly repairing items, therefore diverting from landfill or treatment items that could be reused. With the exception of organic waste to be composted in the gardens of houses, the majority of waste generated in the town will have to be collected from the points of generation and transported to the treatment/disposal facilities. A rail link would not provide sufficient flexibility for this purpose therefore the transfer will have to be carried out by road. To minimise the
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environmental impact and nuisance of this process, it is proposed that where possible electric vehicles will be used. In the case of food waste from flats, the installation of food disposal units in the kitchen sink would allow for transfer of waste via the foul water treatment network rather than by road. Installing food disposal units is only a viable option if a strategy is in place for treating food waste combined with sewage waste. The potential of this option will be reviewed with Thames Water at a later stage. With regards to the treatment of waste, dry recyclable streams (e.g. paper, plastic, metal, glass) will continue being recycled via the Alton MRF facility, as this is a successful system that has put East Hampshire in the top 20 Councils in the UK with the highest recycling rates. Where on site composting of organic waste is not possible, it is proposed that food waste is collected for anaerobic digestion (AD) and biogas generation off site. It is proposed that garden and other green waste that cannot be composted at source is transferred to a central composting facility located to the north of the site in the employment area. The compost generated will then be used for the maintenance of the town’s green spaces and/or sold to local gardeners. The residual waste that cannot be recycled or treated on site is currently being burned for energy generation at the energy from waste facility in Portsmouth. This is proposed to remain the case for the Eco-Town, however the target is to progressively reduce the amount of residual waste generated by increasing the uptake of recycling and other lifestyle changes. The generation of construction waste during the demolition and construction phase will also be tackled by retaining as many buildings as possible and reusing some for transition uses. Materials from demolition will be reused in construction where possible and otherwise recycled off site.
5.3 Climate change adaptation No new development will take place in the flood plain around the river and measures will be implemented to minimise flood risk from increasingly frequent storm events. The aim is for 66% of development area to be permeable, to allow easy rainwater infiltration. This will be achieved by maintaining large areas of green space such as gardens and the Green Loop; using permeable paving for cycle paths, pavements and other suitable hard standing areas; and introducing green roofs throughout the site. Sustainable drainage systems (SuDS) will be integrated throughout the development site in the form of wetlands, ponds, swales, infiltration basins etc. to ensure that surface water runoff is slowed down and water is diverted rather than cause overflows in the sewer system. The location of the SuDS will be established when a more detailed plan is developed for the site. Retro-fitting of SuDS to retained parts of the town will be difficult due to space limitations, however green and permeable surfaces will be increased wherever possible. In designing individual buildings the risk of overheating in summer will be taken into account by facilitating natural ventilation, maximising buildings with optimum orientation, introducing shading measures such as shutters or careful landscaping. The use of vegetation within the built environment will also minimise the risk of the urban heat island effect by making the most of the cooling effect of evapo-transpiration from vegetation. The risk of water shortages will be reduced by minimising the demand for water from efficiency measures (see water section) and by the integration of SuDS, which maximise the water retained in local groundwater reservoirs by avoiding surface water being diverted away from the site via the sewer system.
5.4 Next steps Please note that the proposals set out in this document are based on very early stage assessments of what the energy requirements and waste generation of the proposed development are likely to be. As the masterplan progresses and changes in density and layout take place, the proposals could be significantly affected. Because of this it is vital that the proposals keep being reviewed as the masterplan process progresses.
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As the scheme is refined further detailed study will be required to establish the feasibility of all proposals discussed in this document. The guidance provided in this document will remain important as the scheme progresses and it is vital that the spatial implications of the proposals are considered throughout the process. In particular the following needs to be considered: -
Space for a centralised energy centre accessible by biomass fuel deliveries needs to be maintained;
-
Following further investigation, potentially the exclusion zone for a wind turbine needs to be safeguarded;
-
Low density homes need to have sufficient space for solid fuel storage;
-
Space needs to be safeguarded to relocate the household waste recycling centre;
-
Homes should have sufficient space to accommodate recyclable waste storage and onsite composting;
-
As the masterplan develops, the amount of permeable surface area should be constantly reviewed to ensure that the site is in line to achieve the 66%;
-
Following a detailed SuDS assessment, space for SuDS in suitable locations should be safeguarded.
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6 Appendices
Appendix A - Climate Change impacts and risks Our climate is changing. Recently observed trends indicate that climate change is already taking place, including higher average temperatures, more frequent and severe extreme weather events, melting snow and ice, and rising sea levels. Research suggests that climate change will continue throughout this century, with worsening global and localised effects. Because the potential consequences are both severe and widespread, there is an urgent need to adapt our lifestyles and the built environment to cope. Climate science is complex, and uncertainty remains as to what the consequences will be, how quickly change will occur and where the effects will be most keenly felt. The UK Climate Impact Programme (UKCIP) climate scenarios are projections of the changes that could occur across the country at different times over the coming century and for low and high emissions trajectories. The UKCIP02 findings for the South East of England are summarised in the first two columns of Table 11, alongside a list of the potential risks they pose. The population, built environment and natural environment of Whitehill Bordon will have varying degrees of vulnerability to the impacts of climate change. Construction of the new areas of Whitehill Bordon provides an opportunity to incorporate adaptation in the layout and design of the buildings and spaces. The existing parts of the town may be more vulnerable due to age and varying standards of construction, and retrofitting is likely to be costly. This does not make it any less important. In addition, different sections of the population have different adaptive capacity due to various socio-economic factors. For example, young babies and children and elderly people are particularly vulnerable to the effects of heat. Some specific comments on the vulnerability of the town to the various risks posed are set out in the fourth column of Table 11. An initial assessment has been made of the level of risk posed by the various climate change impacts, resulting in ratings of low, medium or high. These are also provided in Table 11, together with a list of adaptation measures that either need to be incorporated into the masterplan or addressed in the design of the new developments at a later stage.
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Climate Change Impact
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Confidence Level
Risk Scenario
Vulnerability
Risk Rating 2020
Indoor discomfort overall
Increased temperature
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High Living and work space
Sleeping space Outdoor discomfort overall
Due to the urban heat island (UHI) effect, higher temperatures may be experienced in buildings in higher density areas of the site, particularly at night. This can affect the feasibility of passive cooling strategies which may rely on cooling the structure of the building overnight using cooler night time air. If temperatures are not successfully managed then occupiers may resort to mechanical cooling with consequences for the energy strategy and carbon reduction. People expect to have greater control of thermal comfort in the indoor environment than outdoors, so are less flexible. Offices, schools and other locations with high daytime occupancy likely to be most vulnerable. Buildings with high internal gains (e.g. offices and highly glazed buildings) may already be affected by overheating and will find it more difficult to adapt to higher temperatures without mechanical cooling. Existing buildings may be more affected as cooling systems may not be designed to cope with higher temperatures. Passive cooling strategies may be less feasible. Discomfort experienced may be more severe in sleeping spaces, where typical comfort temperatures are lower. Higher temperatures will make exposed spaces unpleasant during longer periods of the summer, although a greater range of temperatures is
MODERATE
MODERATE
Adaptation measures
2080
•
Passive ventilation and cooling
•
Orientate street grain to control solar gains and support natural ventilation
•
Locate naturally ventilated buildings away from noise and pollution sources and close to green or blue space
•
Encourage narrow plan buildings and avoid single aspect units
•
Plant large canopy trees to shade and incorporate green roofs and/or walls
•
Private outdoor space with shading
•
Building integrated shading
•
Shaded connectivity, using trees, trellises and other shading
HIGH
HIGH
MODERATE
HIGH
MODERATE
HIGH
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tolerated outdoors. Exposure to direct sunlight is likely to exacerbate perception of thermal discomfort Parks and open spaces
Less vulnerable than the urban environment due to cooling effect of green space. People using the area for sporting activities may be more affected.
Roads, cycling routes and footpaths
Higher risk of thermal discomfort. Large areas of impermeable hard surfaces store heat and there is less of a cooling effect from evapo-transpiration and evaporation than would result from permeable surfaces such as green open spaces. Thermal discomfort could be exacerbated by physical activity such as cycling. Potential disruption to transport networks in extreme and prolonged heat, affecting road surfaces.
Public transport
High occupancy, especially at peak hours, will exacerbate overheating and perception of discomfort. Potential disruption to transport networks in extreme heat, affecting road surfaces and rails (if applicable).
LOW
MODERATE
MODERATE
MODERATE
•
Green grid and integrated SuDS network
•
Permeable surfaces
•
Provide shaded seating areas and drinking fountains
•
Permeable paving on residential distribution roads subject to light traffic
•
Shading from tree canopies or alternative green or built infrastructure
•
Adopt materials and construction techniques for infrastructure which are more resilient to high temperatures
•
Incorporate shading and reflective surfaces, e.g. roofs painted reflective but antiglare paints
•
Ensure adequate ventilation
•
Encourage alternative modes of transport, especially walking and cycling
•
Adopt materials and construction techniques for infrastructure which are more resilient to high temperatures
HIGH
HIGH
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Water shortage overall
Decrease in summer rainfall
Medium
For drinking
For nonpotable uses
The site is in an area of serious water stress, which may be worsened by droughts. Increasing the density of development of the site could lead to increased water stress without intervention. However, it is currently understood that a well and borehole currently used by the MoD, together with improved water efficiency in the existing town, could supply sufficient water for the new development. Availability of water for drinking is not expected to be affected, but there may be more demand for drinking water in hotter weather. Using alternative local water sources to the mains supply, e.g. harvested rainwater, is more difficult and potentially expensive for potable uses because a higher standard of treatment is required, so the mains supply is expected to be prioritised for this use.
In cases of drought, availability of water for nonpotable uses may be restricted.
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LOW
LOW
LOW
•
Use mechanical ventilation as a last resort
•
Improve water efficiency
•
Greywater recycling
•
Rainwater storage for nonpotable uses, including irrigation
•
Adopt materials and construction techniques for infrastructure which are more resilient to high temperatures
•
SuDS to recharge aquifers and filter pollutants
•
Efficient use of water
•
Non-potable water main to supply homes and businesses
•
Rainwater storage for nonpotable uses, including irrigation
•
Greywater recycling
MODERATE
LOW
MODERATE
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For irrigation
Decreased water quality
Increase in winter rainfall and intensity
High
Storm water drainage and flooding damage
Degradation and failure of drainage infrastructure
During a drought, this is traditionally one of the first uses of mains water to be restricted, through hosepipe bans. But, irrigation is necessary to maintain beneficial effects of green infrastructure including cooling.
Incidents of groundwater pollution may occur following prolonged dry periods, when first rainfall washes away dust and other pollutants. Impact on drinking water supply will depend on the water treatment works’ capacity to cope. The Strategic Flood Risk Assessment for East Hampshire notes that there is a risk of fluvial flooding in the immediate vicinity of the River Wey and Deadwater Stream, which run through the town. There is a risk of groundwater flooding in several locations. Floods could be more frequent and more severe as a result of climate change. To ensure drainage capacity is not exceeded, surface water run-off must be restricted to that of the existing site. Climate change is expected to increase run-off rates at times, which will require
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MODERATE
LOW
MODERATE
MODERATE
HIGH
•
SuDS to recharge aquifers and filter pollutants
•
More efficient irrigation techniques
•
Rainwater storage for nonpotable uses, including irrigation
•
Greywater recycling
•
SuDS to recharge aquifers and filter pollutants
•
Xeriscaping is an option where irrigation cannot be guaranteed
•
SuDS to recharge aquifers and filter pollutants
•
Source control of pollution
•
Avoid building in high risk areas
•
Permeable surfaces
•
SuDS to provide temporary storage and restrict run-off rates
•
SuDS to encourage drainage and provide storage
MODERATE
HIGH
HIGH
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Increase in strong winds in winter
Reduction in soil moisture content
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additional run-off storage capacity to enable this target to be achieved. Although the scenarios have low levels of certainty in this area, the effects of strong winds might be exacerbated by tall buildings in high density areas. Existing building stock may be more vulnerable to storm damage.
Low
High
Degradation and failure of foundations of buildings
Table 11: Climate change impacts and risks
Depending on the topography of the site and the ground conditions, climate change may have an impact on ground stability, in particular the risk of subsidence, heave or landslide. An initial review of available British Geological Survey (BGS) mapping data suggests that there is a low risk of significant and widespread ground stability issues in the study area.
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LOW
LOW
MODERATE
LOW
•
Avoid creating unnecessary wind canyons
•
Assess local risk following ground investigation
•
In areas where a stability risk is identified: - Strengthen structures - Use flexible construction - Use SuDS and control soil moisture - Use vegetation to stabilise slopes or re-grade land