Building Design and Performance Critique Ellison Building
Student Number: W11003712 Advance Measurement and Technology Module: BE 0898 Module Tutor: Alan Davies Date: 10th February 2015 Word Count: 2171
Student Number: 11003712
BE0898
Contents 1.0
Introduction........................................................................................................................................II
1.1.1: Ellison Building: .................................................................................................................................II 1.1.2 UK Environmental Targets .................................................................................................................II 2.0 Development Options ............................................................................................................................. IV 2.1.1Leave and Maintain the current building: ........................................................................................ IV 2.1.2 Demolish and replace (new build): .................................................................................................. IV 2.1.3 Refurbish the current building: ........................................................................................................ IV 3.0
External Elemental Recommendations ............................................................................................ VI
3.1.1 Rain Screed over Clad System:......................................................................................................... VI 3.1.2 Case Study – GE Fogg Building (Queen Mary University London) ................................................. VIII 3.1.3 Financial Gain:...................................................................................................................................IX 3.2.1 Windows: ...........................................................................................................................................X 3.2.2 U and R Values: ..................................................................................................................................X 3.2.3 Solar Heat Gain Coefficient & Visible Transmittance .......................................................................XI 3.2.4 Solar Glare:...................................................................................................................................... XII 4.0
Elemental Service Recommendations ............................................................................................ XIII
4.1.1 Boiler: ............................................................................................................................................. XIII 4.1.2 Distribution of Heat: ...................................................................................................................... XIV 4.1.3 Ventilation ...................................................................................................................................... XV 4.1.4 Renewable Energy Resources: ....................................................................................................... XVI 5.0
Conclusion .................................................................................................................................... XVIII
References .................................................................................................................................................. XIX
I
Student Number: 11003712
BE0898
1.0 Introduction This report is a critique of the potential refurbishment of the Ellison blocks on the Northumbria city campus. Ellison is split into 5 different blocks A, B, C, D and E. Each of the blocks is of similar construction of insitu concrete frames typical of the 1950’s and 1960’s construction for multi storey educational buildings.
1.1.1: Ellison Building: As can be seen on figure 1.1 Ellison building is centrally situated within the Northumbria city campus within Newcastle city centre. Ellison is an educational building being occupied by the faculty of Health and Life Sciences, and the faculty of Engineering and Environment (Northumbria University, 2012). Ellison has numerous client requirements, offices for staff, lecture theatres, laboratories, computer labs and open spaces for students to work. The Ellison blocks (except E block which underwent a £995,000 external refurbishment in 2008) all comprise of single glazed aluminium framed windows with some wooden frames in areas, there is not mechanical ventilation except to the labs, the building is heated using gas condensing boilers which are situated in the basement of A block distributed through radiators situated throughout the building.
Figure 1.1 – lay out of Ellison
1.1.2 UK Environmental Targets The UK government targets to reduce 80% of greenhouse gases by 2050 with buildings accounting for 45% of all emissions in the UK (King, 2013). Gold and Martin (1999) suggest II
Student Number: 11003712
BE0898
that 80% of buildings within the UK by 2050 will have already been built and to achieve this target we much look at making the current building stock within the UK more sustainable as well as new builds. With concrete frame buildings been one of the least energy efficient due to the buildings thermal mass and heat exchange. Aesthetically the buildings also look dated even more so since the construction of city campus east it would be in the universities best interests to attract future students to the university.
Figure 1.2 – Demonstrating breakdown on Co2 emissions in UK
III
Student Number: 11003712
BE0898
2.0 Development Options 2.1.1Leave and Maintain the current building: Option one, to leave the current building and continue maintaining would not be an option that should be taken by the university as the buildings life and maintenance cost will only increase as the building ages.
2.1.2 Demolish and replace (new build): Option two to demolish and replace is a viable option although due to the location and logistics of the building this may be difficult. To demolish and rebuild a new building would be a costly and time consuming exercise. According to BCIS (2013) new build project can cost between 10% - 16% more than a refurbishment. With the building being used by numerous academic faculties decanting costs to rehouse these subjects whilst the works where being carried out would also have to be taken into consideration and the disruption to the university as a whole with the building being situated in the middle of campus. With the building being built in the 1950’s and 60’s is their also a high risk of hazardous materials such as asbestos being present which could cause any demolition works to be time consuming and costly to make sure no materials are released into the atmosphere. This could also affect any planning applications or proposal, if they local council believes there could be a high probability of asbestos present that could be disturbed die to construction works they may reject any planning application. Environmentally this will also increase the carbon footprint of the university as all the rubble will need to be disposed and the embodied energy of the existing building is lost which can often make up to 12 -15% of a buildings lifetime energy (D+B facades, 2014).
2.1.3 Refurbish the current building: Option three to refurbish the existing blocks, is the most logical way to deal with the buildings. As mentioned in the previous paragraph primarily it would be the most cost effect measure. The time constraints associated with a building like Ellison would mean that the refurbishment could be done in sections minimising disruptions and secondary relocation costs to the university, either by doing the work by blocks at a time or by refurbishing each floor so that the building could still be used. The building primarily internally serves well for the use that is intended to demolish the building would be a great waste of expense when what the building really needs to make it more sustainable is to improve the thermal mass as is often the case with post war buildings (Atkins, 2013). Gold and Martin (1999) look at the level refurbishment required in a building and list them in 5 different categories minor/cosmetic, services, structural, major and complete. The refurbishment that would be required on Ellison would be major with the majority of the internals left as they are but an extensive refit to the external façade and services this work according to Gold and Martin (1999) should take on average anywhere between 2-12 months for an office development IV
Student Number: 11003712
BE0898
which should not be that much different for an educational building. With Government pressure to reach their 2050 targets and European energy targets to keep such an unstainable building could not see to be good attitude to be taken by an academic institution by refurbishing the building the university may be able to apply for a grant from the Low Carbon Building Programme as the Queen Mary University did for the G. E. Fogg Building (FraserBrownMacKenna Architects, 2012). The rest of the report will focus on what works would most benefit the building in a refurbishment.
V
Student Number: 11003712
BE0898
3.0 External Elemental Recommendations 3.1.1 Rain Screed over Clad System: Poor cladding of a concrete frame building causes the biggest amount of heat loss and condensation in the winter and most of the heat gain and solar glare within the summer months (King, 2013). One of the first things to fail on a cladding system of a building of this age is the gaskets between the old single glazed window frames and cladding system.
Figure 3.1 – Window Seals Ellison A block
This can be seen on figure 3.1 as you can see where the old Aluminium frame has started to rust. This causes air leakages to be taken into the building within the winter months making any heating less sufficient. Bristol City Council (2012) found that heat loss through the external walls of concrete framed residential blocks was in excess of 1KW/m2, current building regulations stipulate that new builds must achieve a minimum of between 0.18kw/m2 – 0.25kw/m2. If a new external cladding system is installed over the current concrete frames. Ash and Lacy (2015) believe that their Ashtech rain screed system can decrease the heat loss to under 0.25kw/m2.
VI
Student Number: 11003712
BE0898
Figure 3.2 Ashtech Rainscreed System
The Benefit of an over cladding systems also means that demolition works can be kept to a minimum, often in these building the build up behind the slate infill panels will consist of a cavity block wall will insulation, it is quite common that this insulation can often been hazardous materials such as asbestos with an over clad system these materials are left un disturbed and contained (D&B Facades, 2014).
Figure 3.3 Showing Infill panels to Ellison A Block
As can be seen on figure 3.3 the current buildings are not the most aesthetically pleasing and do not feature on much university marketing unlike the city campus east buildings. By VII
Student Number: 11003712
BE0898
updating the current buildings the university could look to make the building a feature of the campus, especially with the competition from other Universities in the country for prospective students the University wants to promote a modern and sustainable approach to its campus buildings.
3.1.2 Case Study – GE Fogg Building (Queen Mary University London) The GE Fogg building situated in the city of London is a perfect case study to examine how an old concrete frame building can go from being run down and out dated to being a winner of many sustainable awards.
Figure 3.4 GE Fogg Building Before and After Renovations
The building originally was not sustainable to heat and experienced high solar glare within in the summer months, with the building being situated in the centre of the University and the city of London the logistics meant that a refurbishment was the only option. Like the Ellison building the Fogg contained labs and lecture theatres. An over cladding system was decided upon to increase the thermal mass of the building and to protect the concrete from further carbonation and corrosion. The end project resulted in solar gain being reduced by 20%, and energy demand reductions of 70% which equates to 5kg/m2 of C02 emissions (FraserBrownMacKenna Architects, 2012).
VIII
Student Number: 11003712
BE0898
Figure 3.5 Heating requirements before and after Refurbishment
. To tackle the issue of solar glare and overheating the windows where calculated to allow enough natural lighting into rooms to minimise the need for lighting. The University benefited from a government grant to laminate photovoltaic cells between the glass windows on the south facing elevations with figures estimating that that this alone would reduce the energy consumption by 33% (King, 2013).
3.1.3 Financial Gain: D&B facades (2015) who carried out the over clad refurbishment to Ellison block E outline that any capital expenditure outlaid on the initial refurbishment can be recovered typically in 18 years or less.
Figure 3.6 Ellison E Block
IX
Student Number: 11003712
BE0898
These capital costs are recovered through the savings that the University will earn by reductions of 70 -80% in heating and ventilation costs. The Ashtech rainscreed cladding is also self-cleaning meaning that any maintence costs are also kept to a minimum. One major advantage to the University is that by carrying out an over clad solution the majority of class rooms can still be used by staff and students meaning that the University does not have to consider decanting costs or missing a year intake of students and income to allow the works to proceed.
3.2.1 Windows: The windows current installed around Ellison are all single glazed windows in aluminium frames these current windows will offer both high U values and low R values. When retrofitting the windows these will be installed as part of the external cladding system.
Figure 3.1 typical U & R Values for different windows
3.2.2 U and R Values: As can be seen above in table 3.1 the U values can be decreased significantly by installing double glazed windows the U value is the measure of heat loss through that structure element and calculated on the rate at which heat transfers through one square metre of a structure (Encon Insulation, 2014). The R value is the transmission of heat by that certain material. The windows that would be appropriate for this refurbishment would be double glazed Low – E windows.
X
Student Number: 11003712
BE0898
3.2.3 Solar Heat Gain Coefficient & Visible Transmittance Choosing the correct windows for the building often comes down to a compromise between these two factors. The buildings requirement is key to looking at these decisions. A perfect window system would utilise as much visible transmittance as possible to increase natural lux levels without incurring significant solar gain that requires mechanical ventilation (Efficient Windows Collaborative, 2014).
Figure 3.7 Thermal emissivity coatings Section
Figure 3.7 shows how low-E coatings can be used to maximise visible light transmittance and reflect unwanted infrared solar gain heat. Windows can be tailored to individual climates with Newcastle being located within the north east where temperatures are often low a window with a low U value should be considered. Low-E windows can cost up to 1015% more than standard windows but can reduce energy loss by up to 30-50% (Efficient Windows Collaborative, 2014).
XI
Student Number: 11003712
BE0898
Figure 3.8 East Elevation A Block Ellison
As you can see from figure 3.8 up to 50% of Ellison’s surface area on the east and west elevations are made up of windows with a large glazed curtain wall to the stair cores. This could cause considerable solar heat gain in the summer months hence the need for low-E controlled windows.
3.2.4 Solar Glare: As mentioned earlier around 50% of Elisions elevations are covered with glazing, when you look at the end use of the building as class rooms and lecture theatres this could cause issues in terms of solar glares. When reviewing many of the current lecture theatres being used they often had cheap blinds installed that where constantly closed to prevent solar glare. This then requires any lighting to be provided artificially and no natural light source is utilised increasing the carbon footprint of the building and the University. One solution to this would be to install solar shading or fins to the building that could prevent solar glare, a well-designed solar shading system can reduce solar glare by up to 80%. The angles can also be adjusted in the summer months to allow for more solar heat gain in the colder months (Kingfisher 2014).
Figure 3.9 Example of solar shading required
XII
Student Number: 11003712
BE0898
4.0 Elemental Service Recommendations 4.1.1 Boiler: Currently the majority of Ellison is serviced by 10 gas condensing boilers which are located within the basement of Ellison block A. After reviewing a number of different sustainable energy productions the most sustainable and cost effect plan would be to leave the current gas condensing boilers. A couple of options that may have been considered was to fit a combined heat and power district heating system
Figure 4.1 CHP System
A combined heat and power systems have become more popular especially within new build large scale public sector schemes such as hospitals. A CHP system means and that all energy and heating power is generated on site this is advantageous to new build large projects as it means that the system can supply energy to the entire project and is not dependent on the grid if their where to a be a power cut this is why many new build hospitals have opted for this source of power generation (Chadderton, 2013). A CHP is more sustainable due to how it uses its heat losses, as you can see form figure 4.1 when power is supplied from a power station 60% of the energy produced is lost the majority of these losses occur when the power is being distributed on the grid from the station to end users (Hall, F. Greeno, R., 2013). Ellison would not be suitable for this type of power generation as it is not easily retrofitted to a refurbishment as a large area is needed to XIII
Student Number: 11003712
BE0898
store the generator also the heating systems within Ellison are a radiant system which is one of the reasons that a gas condensed boiler would be the most sustainable.
Figure 4.2 Gas Condensing Boiler Efficiency
As can be seen from figure 4.1 a Gas condensing boiler is between 75 – 95% efficient. Once the external refurbishment has taken place the heating requirements of the building should decrease by around 40-70%. Condensing gas boilers are most efficient when they are being used with low return water temperatures that are being constantly used (Hall and Geeno, 2013). Instead of replacing the current system a proposal to turn the entire Ellison block and even to incorporate Northumberland into a district heating system. District heating systems can often be more sustainable when all the power is generated in one area (Harvey 2006).
4.1.2 Distribution of Heat: Heat pumps are used to distribute the heat from the source, in this case the condensing boilers around the buildings to the where they are emitted the radiators. How well they do this is measured by their coefficient of performance. To make sure that this is as efficient as possible a number of different factors need to be taken into consideration. The size of the radiators is one of these and the optimum temperature at which the systems run is another (Bosch Group 2010). The peak temperatures for radiators according to Bosch group (2010) is between 50-55 degrees. By install installing weather compensating controls into the system XIV
Student Number: 11003712
BE0898
(WCC) the system becomes self-efficient. Often heating is only turned on within buildings when it is needed and just be set to one temperature unless manual changed, not only is this not the most sustainable heating solution it takes time and management from the estate teams by adding an WCC the system consistently monitors the external temperature to set the temperature of the building at a comfortable level for the users (Iso Enery, 2015).
Figure 4.2 – Weather Compensating Controls flow temperature
4.1.3 Ventilation Current within Ellison there is no mechanical ventilation except to some labs that is need for the fume boxes. Most buildings built pre 1970’s where designed to be naturally ventilated, the problems that occurs is that over the years the usage of buildings often changes for example it is understood that computer clusters have started to be placed with Ellison which add unexpected heat gains to the building, these can be seen in figure 4.3.
Figure 4.3 Expected Heat Gains
Retro fitting a centralised ventilation system throughout Ellison would be a difficult task. Buildings built pre 1970’s have floor to ceiling height is restrictions as it was only ever XV
Student Number: 11003712
BE0898
designed for the lighting electrical fittings to be fitted into the ceiling void (Gold and Martin, 1999). The most suitable system to be fitted would be a localised system in a mixed mode use, to uses both natural and mechanical ventilation. A variant refrigerant volume system would be the most suitable as it can be used for spot cooling and placed in rooms such as computer labs which will be subject to high heat gains (Gold and Martin, 199).
4.1.4 Renewable Energy Resources: The introduction of a renewable energy source to the building what not only decrease the carbon foot it could also be a cost effect saving for the University as with the GE Fogg which used a building integrated photovoltaic system by placing photovoltaic cells laminated within its windows and roof lights (FraserBrownMacKenna Architects, 2012). By doing the building generated 30% of its own power requirements.
Figure 4.4 Ellison Building Locations
As can be seen on figure 4.4 Ellison block A main elevation face east and west if you were to fit any IPS system to these elevations you should look at using a IPS solar shading unit, part of the natural ventilation faรงade design is to already install a solar shades if the University looked to upgrade these to the south westerly elevation.
XVI
Student Number: 11003712
BE0898
Figure 4.5 Example of photovoltaic shades
The IPS per square metre should generate around 22 Kwh per annum. One way to reduce the cost of installing photovoltaics is to include them in the windows on the south facing elevations of block B and D as per the GE Fogg Building figure 4.6 shows the costings per metre square to the project to install 120m2 (King, 2013).
Figure 4.6 – Cost per m2 to project GE Fogg project in install photovoltaics
As can be seen if figure 4.6 the university on this occasion received a government funded grant towards installing the IPS. Although the Low Carbon building Programme no longer exists the University could take advantage of the Renewable heat incentive (department of energy and climate change, 2011).
XVII
Student Number: 11003712
BE0898
5.0 Conclusion Upon reviewing the proposed refurbishment to Ellison the University needs to firstly consider what they foresee the building usage in the future before ant changes are made as this could would affect the design of the building. Internally Ellison for fills its building usage requirements so there would not be much need for any refurbishment, the main issues that the University needs to deal with are the thermal mass and insulation problems with the building faรงade. By expending a capital amount now on these changes the University will save in the long term through their energy usage. As a an Educational establishment the University also has a duty to be sustainable and lower its carbon footprint if a refurbishment was to take place the University should look to achieve a BREEAM rating of over very good or better as well as achieving a B+ government energy rating certificate.
XVIII
Student Number: 11003712
BE0898
References Ash & Lacy Building Systems Limited. (2015) Ash Tech rain Screed Cladding. Available at: http://www.ashandlacy.com/ashtech/ (Accessed 02nd February 2015) Bristol City Council (2012) Over-Cladding and thermal insulation of high rise and low rise flats in Bristol. Available at: https://www.bristol.gov.uk/committee/2012/ua/ua000/0726_9.pdf (Accessed 19th January 2015) Chadderton, D (2013) Building Services engineering. 6th edn. Abingdon. Routledge. Department of Energy and Climate Change (2011) Low Carbon Building Programme. Available at: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/48160 /2578-lcb-programme-2006-11-final-report.pdf (Accessed 20th January 2015) D+B Facades (2015) High rise residential refurbishment. Why high quality over cladding? Available at: http://www.dbfacades.com/db_downloads/Why_High-Quality_Overcladding.pdf (Accessed 17th December 2014) D+B Facades (2015) External Refurbishment of Ageing Academic Buildings: Building the Business Case Available at: http://www.dbfacades.com/db_downloads/d+b_Building_the_Business_Case.pdf (Accessed 17th December 2014) Encon Insulation (2014) Thermal Values Explained - A quick guide to U-Values, R-Values & Lambda Values Available at: http://www.encon.co.uk/customer-centre/technical-centre/general/thermal-valuesexplained-quick-guide-u-values-r-values (Accessed 20th December 2014) Efficient Windows Collaborative. (2014) Window Technologies: Low-E Coatings Available at: http://www.efficientwindows.org/lowe.php (Accessed 05th January 2015) FraserBrownMacKenna Architects (2012) Recladding an Occupied Mixed use Academic Building. Available at: XIX
Student Number: 11003712
BE0898
http://www.fbmarchitects.com/pdf/queenmary.pdf (Accessed 19th January 2015) FraserBrownMacKenna Architects. (2012) GE Fogg Building, Queen Mary University London. Available at: http://www.greendotawards.com/submit/upload/2007/large/3-43511_FBM_Architects_-_Green_Dot_Awards_Entry.pdf (Accessed 27th January 2015) Gold, C. and Martin, A (1999) Refurbishment of Concrete Buildings: Structural and Services Options. Available at: https://www.concretecentre.com/pdf/GN_Refurbishment%20of%20Concrete%20Buildi ngs.pdf (Accessed 01st December 2014) Gold, C. and Martin, A (1999). Refurbishment of Concrete Building: The decision to refurbish Available at: https://www.bsria.co.uk/informationmembership/bookshop/publication/refurbishment-of-concrete-buildings-the-decisionto-refurbish/ (Accessed 15th January 2015) Hall, F. Greeno, R. (2013) Building Services Handbook. 7th edn. Abingdon. Routledge. Isoenergy (2014) Weather Compensation for heating controls. Available at: http://www.isoenergy.co.uk/more-information/weather-compensation-for-heatingcontrols (Accessed 12th December 2014) Kingfisher Louvres Limited. (2014) Solar Shading Benefits Available at: http://www.kingfisherlouvres.com/brise_benefits.html (Accessed 05th January 2015) King, D. (2013) Green facelift for concrete buildings. Available at: http://www.ingenia.org.uk/ingenia/articles.aspx?Index=835 (Accessed 20th December 2014) Queen Mary University of London. (2012) Queen Mary wins second award for GE Fogg building. Available at: http://www.qmul.ac.uk/media/news/items/64110.html (Accessed 27th January 2015) XX
Student Number: 11003712
BE0898
Worcester Bosch Group (2010) Product: Green source and green store heat pumps. Available at: http://openenergymonitor.org/emon/sites/default/files/radiator-sizing-for-heatpumps.pdf (Accessed 2nd February 2015) Harvey, D. (2006) A hand book on low energy buildings and district-energy systems. Oxon. Taylor and Francis.
XXI