Willow Way
Growing the Green Oxford
Background
Context and Masterplan
The West Oxford Masterplan The current site is deing detailed in extension to the existing West Oxford Masterplan (appendix 1). This masterplan was drawn up as part of studio 1 by a team including the author of this plan. The plan identified the strengths and weeknesses of the site and developed a basic plan over a large undeveloped area adjacent to Botley Road, West Oxford (fig 2). Best practice in urban design was followed from sources such as the urban design compendium, responsive environments and shaping neighbourhoods (fig 1).
fig 5; Masterplan
The area was identified as a major flood risk (fig 4) and the requirements of the Oxford flood plan for the site to include a flood relief canal was accounted for (fig 3).
fig 1; Privacy Gradients
fig 3; Site Section with Canal
fig 4; Oxford Flood Risk Assessment
fig2; Site Context
The overall masterplan focused upon the sustainable use of the site. Thia was due to its strategic position in relation to the city and the natural resources available as a greenfield site. Maintaining areas of ecological importance, maximising access to water, optimising solar orientation and establishing a permiable, walkable neighbourhood were the main design actions. The context of this masterplan is the first phase of the larger development, including the community centre and shopping area. It is the highest density area as it is closest to the centre of Oxford and to transport allowing maximum pedestrian, cyclist and public transport use. fig 7; layers of development of the masterplan- Blue, Green, Grey and Built form
Strengths-
Perimeter Blocks, High Density, Plot Diversity, Location, Green Space
Weaknesses-
Community Centre, Corners, Flood Risk
Opportunities-
Improve Community Focus, Strengthen the Sustainability, Provide broad range of housing, Improve water access in Oxford
Threats-
Lack of site use due to conceptual barrier of the park, Political barrier developing on Flood Plain
Masterplan
Development and Specification
fig 6; Phase 1
Design Rationale Sustainablity
As part of the larger masterplan sustainability was highllighted as an important focus for design. Though the political and economic context of the development has changed the possibility of a sustainable development on this site is as strong if not stronger. The changes in the property market and the economic situation makes a home which eliminates the need for expenses such as a car, dramaticly reduces energy bills and provides a pleasent living environment an ever greater comodity. Acheiving sustainability requires a systems approach, with the overall picture being observed at the same time as specific design. The elements which influence design at this level of masterplan are highlighted in fig 8. These elements were used to form design aims which can guide the development and form a part of the rationale. Each design aim is broken down into a design action, a single part which directly influences the design in a described way. fig 8; Masterplan Sustainability
Design Aim 1;
Design Aim 2;
Design Aim 3;
Design Aim 4;
Design Aim 5;
Sun
Passive Solar Orientation and Design 1.1 Energy Production See Energy 3.2 Light for Growth- Productive Spaces 1.2
Water
Flood Managment Plan 2.1 Water Efficiency 2.2 Solar Water Heating See Energy 3.3
Energy
Reduce Transport Energy Energy Production Efficiency
Nature
Ecology Plan 4.1 Aquatic Ecology Protection 4.2 Productive Spaces See Sun 1.2
Materials
Waste Managment Material Sourcing Co-operative Ownership
3.1 3.2 3.3
5.1 5.2 5.3
Design Aim 1 Use the Sun
All energy on the earth originates in the sun. It is absorbed and transformed through plants and annimals to form the resources and materials around us. The fossil fuels our society relies on have undergone a process over throusands of years. To be more efficient however we can source our energy, heat and light in a different way- directly from the sunlight we receive every day. Design Aim 1 involves using this efficient, free energy in a resilient way to heat and light our buildings and produce food for our own energy.
Passive Solar Orientation and Design 1.1 Energy Production See Energy 3.2 Light for Growth- Productive Spaces 1.2
Strategy Maximising solar access of the facades and roof lines to allow for passive gain
The design strategies for building benefiting from passive gain are many and varied. Changes in fenestration, materials, colour and angles are all acceptible and many different strategies may be used on site. The affect upon the urban design masterplan is in street orientation and facade guidelines
which will permit these strategies to be adopted through different archetectural designs.
Design Action 1.1
Passive Solar Orientation and Design
Precedents
Milanfiori Development, Milan, Italy Honeycomb Apartments, Slovenia ICON solarhouse, Minesota
Implementation
Spacing between houses was modified to allow the south facing facades light access even in midwinter as shown below. The streets are oriented south south west, less than 30 degrees from due south. Facade design should maximise fenestration on the south face. The community hub is layered to maximise solar access.
Design Point 1.1 Maximise Passive Heat Gain through fenestration, overhangs and materials according to best practice.
Strategy Using shade analysis to locate the productive areas in the public realm. Urban Orchard Public Growing Space Wild Edible Landscaping
Implementation
Precedents
Guerilas of Love, Nottingham Middlesborough Environment City Brooklyn Urban Farm Union Street Urban Orchard
Areas with the maximum daylight access are highlighted. These are key locations for edible and air filtering plants highlighted below.
fig 12; Areas of Edible Production
Plants for Productive Areas
Trees; Malus Domestica (Apple), , Prunus Family (Peach, Plum, Damson),
Design Point 1.2
Shrubs; Rosa Canina (Rosehip), Ribes Family (Blackcurrent, Gooseberry) Rubes Family (Raspberry, Loganberry)
Maintain places highlighted on the plan for productive plants suggested in the guidance.
Herbs; Acinos Arvensis (Basil), Foeniculum vulgare (Fennel), Lavandula x intermedia (Lavender), Mentha spicata (Spearmint), Origanum vulgare (Oregano) fig...; Air Filtering Plants
Design Action 1.2 Light for Growth
Design Aim 2
Water Water Everywhere
Water is essential for life. Recently however climate change and unsustainable development has led to water being a threat to livelyhoods and housing. The sustainable use of water and restoring natural water cycles assist in mitigating these circumstance. The development will restore these functions and assist in mitigating local flood events in spite of it being development on a flood plain. Strategies for absorbing, storing and slowing down rapid or persistant rainfall while ensuring the efficient use of water within homes to reduce stress on water treatment and storage will all be examined under Design Aim 2.
Flood Managment Plan 2.1 Water Efficiency 2.2 Solar Water Heating See Energy 3.3
Strategy
Minimise hard surface on site and allow for absorbtion of 100 year floods.
Implementation
Design Action 2.1 Flood Management Plan
The flood managment plan for the site follows best practice for sustainable urban drainage systems (SUDS) by including infiltration areas (green space) retention areas (beneeth boardwalks) and permeable paving. The canals on site retain nearly 4000 litres of water at low flood times however as a flood control measure this can multiply by half before the retention areas beneeth boardwalks becomes necesary. The inclusion of green roofs and rain collection systems also reduces the pressure on the flood system in times of sudden water events.
Precedents
Upton, UK Elvetham Heath, Hampshire Riverside Place, Stamford
Design Point 2.1
Flood plain space will be maintained as much as possible and all hard surfaces consist of permiable surfaces or have a collection system in place.
Strategy
Reduce water use in the development through efficiency measures.
Precedents
Cloughjordan Ecovillage, Tipperary, Ireland Bedzed, London
Design Point 2.2 Implement water efficiency protocol through water reuse and storage facilities.
Implementation Water efficiency can be increased through reduction of uses and reuse of water. The reuse of water is known as a grey water system. The water entering a building fromt he mains is processed to a standard of cleanliness for drinking, this is higher than the requirements for other activities such as washing clothing, dishes or flushing toilets. Grey water systems use this fact to use water twice- the first time from showers and sinks and the second time through washing machines, toilets etc. The efficiency can be further increased by sending the water (excluding toilet water) to storage for use in the garden etc. At an urban design scale this effects the design by increasing the garden sizes needed for underground storage tanks.
Design Action 2.2
Water Efficiency
Design Aim 3 Energy
Design Aim 3s purpose is to reduce the environmental impact of both our buildings and lifestyles by efficient use of energy. The energy use of a building is focused upon space heating and lighting. The reduced heating load of passive gain houses combined with a stratgic energy plan for the site will assist in lower impact housing however the impact of lifestyle is equally as important. Day to day our energy used outside of buildings is mostly dedicated to transport. This fact combined with the location of the site in close proximity of the city centre makes a tansport plan an essential part of achieving long term energy savings onsite.
Reduce Transport Energy Energy Production Efficiency
3.1 3.2 3.3
Implementation
Strategy
Encourage journeys by low energy methods
Reducing car use and facilitating journeys for pedestrians and cyclists is supported by a high degree of permiability onsite. The connected street plan allows choice in the routed and a variety of experience. This is highly restricted for car users as motorised access to the site is discouraged through the paving, lack of parking and reduced permeability at canal crossings and on north south streets. The required width for
the access of rubbish collection and emergency vehicles is available on all canal streets however the lack of marking or verticle elements will clearly define the area as pedestrian dominated. In addition to this a car club with mainly hybrid or electric vehicles will have designated spaces on the site to discourage car ownership. Some parking will be available at additional fees in the community centre. Strategies for
Design Point 3.1
Encourage non motorised transport through and off site by reducing motorised permeability and providing cycle facilities.
Design Action 3.1 Reduce transport energy
encouraging bicycle use include secure indoor storage in each household, shopping trailers available at shops such as those offered by waitrose. Public cycle parking should also be widespread.
Precedents Geos Net Zero, Colerado Bedzed, London Freiberg, Germany
Strategy Use the natural resources of the site to produce energy and heat.
Implementation
Renewable energy sources are abundant on the site. Wind, water and sun are all possible with varying degrees of efficiency. Due to the strict protection on the oxford skyline wind is unlikely to be allowed on site. The presence of many water sources gives potential for microhydro generation however the lack of a gradient on site would make it inefficient. The resource which is most abundent and efficient in this case is solar. Energy generation from the sun occurs in 3 ways, directly through photovoltaic cells, or solar panels as they are know, indirectly through the heat of the sun warming the soil (ground source heat pump) or water (solar water heaters) or indirectly through the use of plants for energy, known as biomass. On the larger site there are potential spaces for biomass generation however in this phase as the densest area of the development it is greatly reduced. The solar panels as a power generation method is applicable in this phase. In order to optimise the solar panels roof angle is an important factor. All the roof lines will be oriented east-west to provide a south face and avoid uneccesary scaffolding. The south face should be angled within 30 degrees of the latitude of the site. This leads to a distinctive roof line within the development which could also become a point of legibility within the development.
Precedents
Selwyn Street, Oldham, UK Fujisang, Japan Solar City, Canada St Helens, UK
Design Point 3.2 Orient roof lines east-west and angle the south roof face at 40 to 60 degrees to optimise solar panel application.
Design Action 3.2
Energy Production
n
Strategy
Optimise energy efficiency on site through building materials, structure and construction methods and systems buildings.
Implementation
Energy efficiency within the construction phase and in the finished building reduces the overall environmental footprint of the building. Methods for energy efficiency can be broken down into to categories- construction and lifetime. Efficiency during construction has financial and temporal benefits, allowing shorter development times, lower risks and more rapid return on investment. This can be acheived in a number of ways including prefabrication, modular construction
Precedents
Smartcity Developments Beehive, Slovenia KT2, Archexpo Bedzed, London
Design Action 3.3 Increase Efficiency
The lifetime energy efficiency of the building method must also be considered, a rapid construction which is of poor quality and low lifetime efficiency would not decrease the environmental footprint and vice versa. The energy efficiency can be measured using the compound U values of building materials and accounting for design factors.
Design Point 3.3
Preference will be given to building techniques which increase the efficiency of construction while producing a quality, energy efficient building.
Design Aim 4 Nature
Integrating nature into urban areas provides many benefits. As a green field site the area is currently supporting many different wildlife types and providing local benefits as a recreation space. The development will decrease the groundcover of natural areas however the biodiversity and suplementary benefits may be maintained. Design Aim 4 focuses on integrating the development with ecology in ways which may benefit both humans and wildlife.
Ecology Plan 4.1 Aquatic Ecology Protection 4.2 Productive Spaces See Sun 1.2
Strategy
Living Wall
Providing habitats to mitigate the natural destruction of development on the site and to maintain the benefits of nature.
Implementation
The ecological survey of the site completed for the large scale masterplan identified key areas of ecology to be maintained, one of whoch forms a corner of phase 1. This bridleway is an important local resource, provides a rural recreatiion in proximity to the urban centre and acts as an informal community meeting place. As such the area is reserved as a woodland walk. Within the urbanised area of the site the oportunities for wildlife integration are varied. The provision
Design Action 4.1 Ecology Plan
Wildlife Walk
Potential Green Roof Areas Gardens Public Planting
of green roof space acts as a habitat for hardy flora species and birds, Gardens can act as wildlife reserves and studies have shown may have greater biodiversity than rural lands, Public planting allows oportunities for native plants as well as the edible productive landscapes designated under design action 1.2. Finally a living wall along the interface between the wildlife walk and built formwill offer bird and bat boxes as well as planting.
Living Wall
Precedents
Wildlife Walk
Milton Keynes GI Plan, UK Middlesborough Environment City NYC Green Infrastructure Plan, NYC Bankside Urban Forest
Design Point 4.1
Maximise oportunities for wildlife through designed street planting, green roofs and the sensitive landscaping of the wildlife walk Green Roof
Strategy Use infiltration areas to filter water and prevent polution of watercourses on site.
Implementation
Precedents
Upton, UK Elvetham Heath, Hampshire Riverside Place, Stamford
The methods highlighted for flood prevention on site are combined in protecting the natural watercourses on and adjacent to the site. Part of this strategy also requires as much of the watercours as possible to have natural, soft verge sides to allow the biological filtration of the water.
Design Point 4.2
Prevent environmental polution to the watercourses on site using natural filtration systems through infiltration areas and natural sided canals.
Design Action 4.2
Aquatic Ecology Protection
Design Aim 5 Materials
The materials we use to produce our dwellings have a huge impact upon our environment. Recent developments in project managment requirements mean the full lifecycle of buildings is being taken account of however the sources of materials is still a concern. The materials which are used in a community once the construction is finished is also a concern for the ongoing sustainability of an area. Integrating closed loop systems onsite, reducing consumption and encouraging reuse are all positive ways of optimising our resources and contributing to a sustainable community. These are the purposes of Design Aim 5.
Waste Managment Material Sourcing Co-operative Ownership
5.1 5.2 5.3
Strategy Promoting waste reduction on site by facilitating easy waste managment
Precedents
Preloved. UK Sunflower Recycling, Dublin Ditmus Park, Brooklyn
Implementation Waste managment is a major issue, with the average person in the UK producing 600kg a year. Many strategies can be ancouraged onsite for waste. The integrated front storage areas highlighted in design action 3.1 creates an oportunity for waste storage in building without unsanitary build ups within the dwelling. Internal chutes for seperate waste streams would reduce bariers to sorting recycling caused by lack of space or ease of system. Composting could be encouraged on plot but food waste could also be collected on site for composting in allotments. Custom built cycle trailers have been developed for this in Brooklyn . Waste collection in the public realm can be encouraged through solar compacting bins which can take dry or wet waste and dont require underground storage or regular collection.
Design Action 5.1 Waste Managment Plan
Design Point 5.1
Install solar compacting bins in the public realm and allow internal waste seperation in residences through dry waste chutes and compost/food waste collection
Strategy Sustainable sourcing of material, locally if possible.
Precedents
Cradle to Cradle Certs FSC Wood Accoya Buildings Interface flor
Implementation Materials sourced for use on the site should be analysed under a sustainability framework such as the natural step or cradle to cradle. The products suggested for use in the public space plan are accoya wood for the boardwalks and Sureset permeable paving for hard cover areas.
Design Point 5.2 Source local sustainably certified materials as much as possible.
Design Action 5.2
Materials Sourcing Guidance
Precedents
Strategy Using cooperative ownership and membership lease system for little used or ocasional items.
Implementation Cooperative ownership systems are not new, public libraries being one of the oldest examples. Extending this concept to items such as household tools which are rarely used or cars and bicyces which are required only for a small proportion of our time will decrease the need for ownership of these items and make them more efficient. Car Club spaces are to be located on each block. Shared bike systems with a variety of bike types such as cargo bikes or trailer rental will be installed at the community plaza and major junctions. A small retail unit will be set aside on a reduced rent for a community cooperative for other household items such as electrical goods and gardening tools.
Design Action 5.3 Ownership Coop
Bike Coop, SFPIRG and other Unis Tool Coop, Fort Collins, Co Public Libraries Barclays Bike, London Car Clubs
Design Point 5.3 Design areas for cooperatives and libraries to oporate on site for house and garden tools, bicycle accessories and repairs etc.
Design Inspiration Motif
Willow Weaving
Coppice Catkin
Weeping
Material Street
Building
Detail
Furniture
Art
Shape
Texture
Colour
Motif Willow
Realising the Design Actions Step 1- Site Layout
Design Point 3.1Restricted access for motor vehicles but not pedestrians Design Point 4.1Protected wildlife walk for ecology
Design Point 1.1 and 3.2Solar orientation of streets and roofs
Design Point 3.1 and 4.2Storage Spaces to the front Design Point 3.1Limited Parking for car club
Design Point 2.1Permiable surfacing to reduce flooding
Realising the Design Actions Step 2- Roof Plan
The solar roof area is optimised for colection of solar radiation by the angle of the eaves and orientation towards the south west.
Accessible or Green roof area is alocated for the provision of recreation space on apartment blocks or nature spaces on houses.
All roof lines are oriented East-West in order to maximise the south facing for solar gain- either for energy production as in Design Action 3.2 or for passive gain as in Design Action 1.1.
Bringing it all Together Step 3- Street Design
Integrating all the design actions into a coherant street design.
Main Square- Facades The blocks surrounding the urban square have ground floor flexible use units which are intended for retail but may also have office use. The second, third and fourth floors are residential with all access directly from the plaza.
Main SquareFeature
Water
Shalow stepped design for easy interaction with water. Changing water level in response to on site canal levels.
Main Square
Canal Streets-Street inspiration and materials The use of varying materials and shapes in the streets to provide different spaces for different functions. Wooden boardwalk to emphasise the water on site and allow overhangs to the canal or mooring spaces at each house, Hard surface for the required access by motorised vehicles but also to provide recreation,, transport and play space.
Canal StreetsFacade and Front Garden The integration nature into the street and allowing greater sense of ownership in the public space is encouraged using front gardens and raised planters.
Canal Streets
Walkway Streets-Street inspiration and materials The walkway streets are smaller, more residential and intimate in character than the canal streets. They have no motorised vehicle access but are short, no more than 30 meters from a stopping point or car club space. The materials reflect this by the reduction of hard surface and the dominance of wooden boardwalk and planting.
Walkway Streets
Delivering Sustainability Certifying
Competing Sustainable Accreditation Programs Name
LEED for Neighbourhood Development
BREEAM Living Communities Buildings Challenge
Natural Step Framework
Code for Sustainable Homes
Begun by the US Green Building Council, LEED ND is the premier accreditation sought worldwide. It functions on a marking system under a number of criteria and ratings come in Silver, Gold or Platinum.
Developed in response to the Code for Sustainable Homes in the UK BREAM is focused upon building efficiency but has a section for BREEAM Communities.
Writen by the Cascadia Green Building Council the Living Buildings Accrediatation is known as the most robust and diffucult sustainability accreditation currently available. It accounts for development at all scales
Summary of Relevant Criteria
Smart Location Neighbourhood Pattern and Design, Green Infrastructure. See Appendix 3.
Site Water Materials Equity Beauty Energy Health
Is the design compliant? Why?
Yes
climate and energy place shaping community ecology transport resources business building See Appendix 3 Yes
The Natural Step iss not a framework secifically for development or buildings but a model for creating sustainable systems in complex situations. Used over many industries and situations its accreditation progam is open but follows basic principles Human Need Natural Degredation Unnatural Accumulation Local Materials
No
Yes
Code for Sustainable Homes was developed by the UK government as a route towards a sustainable built environment. With increasing levels of requirements to allow for a sttep change in building regualtions towards low impact housing. Energy/CO2 Water Materials Surface Water Run-off Waste Pollution Health and well-being Management Ecology Yes
The design falls well within the accreditation criteria provided robust community consultation takes place.
Building on a green field site is immediate removal from the accreditation system
Provided the masterplan is followed the development should fall within the natural step framework.
Explanation of the Accreditation Program
The design is highly compliant except in its location on a green field, floodplain site which is accredited for by the canals and suds and its proximity to the city centre.
None of the design criteria impeade the ability of each plot to fulfil code for sustainable homes standard 6 and the solar roof and passive gain plans contribute to complience.
Delivering Sustainability Financially
Delivering Sustainability Going full circle
Strengths-
Weaknesses-
OpportunitiesThreats-
Sustained Perimeter Blocks, High Density, Plot Diversity, Location, Green Space
Community Centre, Corners, Flood Risk,
Improve Community Focus, Strengthen the Sustainability, Provide broad range of housing, Improve water access in Oxford
Lack of site use due to conceptual barrier of the park, Political barrier developing on Flood Plain
Maintained Maintained Increased Maintained Maintained
Worked arround Built form improved with the inclusion of a plaza Corners were investigated and best practice implemented Flood Risk is mitigated by the canals, suds and green roofs
Obtained
The central location of the site provides a community resource and The focus on sustainability has provided a robust environmental and economic plan for the site Variety of housing types and sizes with a large preportion of affordable is planned onsite The canal treatment allows for access to the water through the boardwalk and as a recreational facility
Taken account of
Recomend that the landscaping of the park allows ofr community interaction and strong desire lines The development of the canal to relieve flooding through botley road is currently unfunded, this development would provide half of the infastructure and would act as a temporary measure.
Appendix 1 Design Guidance
Design Point 1.1
Design Point 3.1
Maximise Passive Heat Gain through fenestration, overhangs and materials according to best practice.
Encourage non motorised transport through and off site by reducing motorised permeability and providing cycle facilities.
Design Point 1.2
Design Point 3.2
Maintain places highlighted on the plan for productive plants suggested in the guidance.
Design Point 2.1 Flood plain space will be maintained as much as possible and all hard surfaces consist of permiable surfaces or have a collection system in place.
Design Point 2.2 Implement water efficiency protocol through water reuse and storage facilities.
Orient roof lines east-west and angle the south roof face at 40 to 60 degrees to optimise solar panel application.
Design Point 3.3 Preference will be given to building techniques which increase the efficiency of construction while producing a quality, energy efficient building.
Design Point 4.1
Maximise oportunities for wildlife through designed street planting, green roofs and the sensitive landscaping of the wildlife walk
Design Point 4.2 Prevent environmental polution to the watercourses on site using natural filtration systems through infiltration areas and natural sided canals.
Design Point 5.1
Install solar compacting bins in the public realm and alow internal waste seperation in residences through dry waste shoots and compost/food waste collection
Design Point 5.2 Source local sustainably certified materials as much as possible.
Design Point 5.3 Design areas for cooperatives and libraries to oporate on site for house and garden tools, bicycle accessories and repairs etc.
Appendix 2 Overall Masterplan
Appendix 3
Environmental Accreditation Criteria