Located at the heart of the country Derby is a fast growing and vibrant city with strong historic links with the engineering history of the United Kingdom, although this is a fact well know by locals it is also an unjust reality that the cultural and enterntainment scene of the city has being always laking a well equiped and fit for purpose entertainment venue that matches the ambitions and achievements of the city.
We are proposing the design of a new concert hall - pavillion venue to host culltural and enterteinment events. It will feature the use of sustai-nable, environmentally resilent and innovative measures. The design makes the best use of the site and its potentials, as explained in the masterplan. The location of the pavillion is over the north area of the site and the building orientated for solar and heat gain in the coldest winter days and extensive vitas over the riverside and historic buildings like the Derby Cathedral, Derby City Council Building and the Silk Mill.
The building is raised ten meters from ground level as a buffer area against flooding and to allow the creation of a ‘outdoor theatre’ space for public performances underneath it. The concept of the Derby canal will let the building to have its own water supply with filters powered by solar energy to clean and recycle grey water back to the river. A new hydro-turbine in the proxility of the weir will increase dramatically the availability of renewable energy not only for the building but for the rest of the area.
Materials used in the fabric of the building include bluegreen low-E (e=0.05) glass, fiberglass insulation, metal sheets and wood panels for the interior. A resilent approach to flooding was used to the building structure and interior walls, all components are recyclable, easy to man-tain and replace or demolish.
Benefits from a concert hall pavillion include the fact that the location of the site next to the A52 and to the city centre will reduce energy consu-med by the audience travelling to the theatre, and the proximity of the new bus station and Derby’s train station adds to the convenience of this proposal.
The proposed design maxi-mises the use of the land available on a floodplain site. It will create a new comcep-tual ‘Cultural Quarter’ much needed for the city of Derby.
Attempts to create multipur-pose theatre venues have generally failed to meet all types of different theatrical and acoustic performances in a single room. The propo-sal here is to use technology to vary the acoustics, width and height of areas like the procenium.
The Pavillion is raised from the ground creating a ‘shel-tered venue’ for public performances and cultural events in the warm season. Entensive glazing facades to allow natural light and solar gain as well as an ‘welcoming’ and inviting effect on passersby.
ENERGY ANALYSISFrom the first energy analysis run it was found some key data regarding the buildings impact on running costs and environmental impact, especially in energy use and management. The life cycle electricity use (for a design life of 30 years) was just over 35 million kW/h. The effect of running alternatives on double and finally on triple glazing and increased insulation from 50mm to 100mm on exterior walls resulted on a significant re-duction of the cost to just above 20 million kW/h, 20% less.
Annual energy use is £203, 490 from which 65% (6,394,442MJ) corresponds to fuel comsuption. Fuel counts for more than £100,000 year on running costs, this has to be addressed. HVAC consumes 81% of the total fuel annual use, it is recommended to design pas-sive and sustainable systems on ventilation, heating, and air conditioning to help reduce this figures.
Final run with triple glazing and better insulation resul-ted in reduction of just over 250,000 kW/h in electricity use in HVAC compared with previous runs with single and later double glazing. This potentialy saves £24,000 on electricity consumption.Window conductivity was halved from -800,000 MJ to less than -300,000 MJ on january in the third and last run. This reflects and improvement but further design decisions must be taken.
The lack of substantial thermal mass on the building fabric has a negative effect on monthly heating load analysis results. Infiltration is also remarkably high with about 150,000 MJ a month.Monthly cooling load analysis shows a high level of energy consumption for the period april-september, ventilation systems need to be designed to tackle this situation.
GREEN BUILDING STUDIO / ANALYSISBASE RUN RESULTSInitial design development ideas focused on the curtain wall facades, especially over the south atrium. Knowing that this large glazed walls would compromi-se the thermal performance of the building was a fact and the results of the first run recorded annual energy use of 943,960 kW/h in electricity and 6,394,442 MJ in fuel. This was an improvent from a test run with single glass windows and 50 mm insulation recorded 1,950,167 kW/h electrical and 16,061,550 MJ fuel usage.
Natural ventilation potential meassured in possible electric energy savings of 151,092 kW/h resulting in possible annual electric cost savings of £15,109.Photovoltaic potential is also remarkable, estimated in £22,035 kW/h on annual energy savings.
A final run was requested with a design alternative for the fabric of the building, including a revision of the materials and insulation for roof and walls. The simula-tion below shows the minimum possible thermal per-formace for the type of building proposed. The results of this final run were dramatic with recorded annual CO2 emissions of 131.1 Mg, far away from the 652.9 Mg of the initial tjest run.Electric annualm consumption was 531,607 kW/h and fuel 6,058,210 MJ.
Lifecycle energy was almost halved from 28,318,794 kW to 15,948,222 kW of electricity. Estimated energy and cost summary saw a potential annual energy sa-ving of nearly £50,000 a year and £2,132,048 over the lifecycle (30 years).
GREEN BUILDING STUDIO / ANALYSISBASE RUN RESULTSBasic roof u-value was an ‘almost average’ 0.35 and exterior CMU wall u-value of 0.46. East and west faca-des had a metal panelled wall with u-value of 0.19.Other results included average lighting power density recorded 12.91 W/m2 and reduced to 2.52 W/m2 in the final run. Most readings recorded quality improve-ments at the final run (right had side graph).
FINAL RUN RESULTSGreen building studio tested a alternative design for the buildings fabric and resulted in dramatic reduction in u-values for roof and exterior walls. The new pro-posed roof was the R60 Wood Frame Roof (see detail below) with a staggering u-value of 0.08.Similar situation for the exterior wall with a new recor-ded u-value of 0.12. These changes had a tremendous effect on the final calculations of the building’s perfor-mace.
Photovoltaic potential annual energy production was esti-mated in 22,035 kW and potential cost savigs per year of £2,203,47. This represents only a small fraction of installed panel area:157m2 from a total roof area of 8,515m2. The roof design and angle of the sections could be modified to allow the efficient installation of further more PV panels.
CARBON FOOTPRINT STUDY
According to the results of the study potential energy generated by a roof PV solar panel system (working at high efficiency) could generate a maxi-mum of around 1 million kWh/year with a carbon negative effect of 380 me-tric tons /year of CO2. This alone is not enough to make the building carbon neutral but on the other hand, surplus of energy created in summer can be sold to the national grid to create income.
Alternatives need to be considered including hydro power turbine gene-rated energy. At a cost of around £1.7 million and producing 230 kW/h the Longbridge hydro-turbine is being used to power Derby City Council building. A similar system can be use on the opposite side of the weir just next to the site. In winter and by night time hydro-powered energy can supplement the energy demands of the building, when solar energy is less efficient.
During the first run of the anaysis we found a significant level of carbon emissions in metric tons per year so an assessment of the building fabric concluded in the necesity of increasing insulation thickness from 50mm to 100mm for exterior walls and from low E double glazing to triple glazing panes. This two changes had a dramatic impact on the building performan-ce which is shown in the graphics at the right hand side. Carbon emissions were down from 970 metric tons to 650 metric tons / year and annual energy use (the main contributor on carbon emissions) reduced almost one third from £305,736 to £203,490.
RECOMMENDATIONS:Energy management as a strategy to maximise energy use. Technology can play a part in the design of a ‘smart’ building with computerized interior cli-mate management, use of heat recovery systems for ventilation and natural light features. Intelligent buildings make better use of resources and limit energy waste with a possitive effect on reducing carbon emissions further down.
Solar access analysis showing areas of maximum and mi-nimum solar radiation. Solar roof would benefit from intense solar radiation all year long. Large roof coverage to reduce solar gain in summer and face-ted structure to capture solar rays from all directions.A buffer zone between the ou-ter roof and the main building is recommended to prevent a greenhouse effect on the building.
SUN CAST STUDY /SUMMERGraph showing sun cast analysis on summer’s solstice day, high levels of summer exposure over the roof, the faceted design would harvest solar power in all directions. Protruding roof panels to shade the south, east and west facades, solar gain over the roof could be a problem and additional na-tural ventilation meassures need to be considered to mantain thermal com-fort in summertime when most events are normally held during the evening.
Most elevations remain in shade during the summer months and the su-rrounding canal and commercial areas are not compromised despite the scale of the building. Most shading on the afternoon will fall over St Alk-mund’s Way pass at the north east of the building.
Minimum impact over adjacent public spaces. Only south atrium overexpo-sed, solar shading solutions should be considered. Overall the building is having adequate protection from direct sunlight and glare.
Solar study on the 21th of june at 6pm to show solar penetration over the west elevation and at ground level underneath the building.
SUN CAST STUDY / WINTERMidday on the winter solstice and full exposure on south elevation, some mechanical solar shading systems to be considered. There is intense solar gain on this area but from weaker winter sun. Extensive solar exposure on the ground floor external public space.
13:00pm on the 21th of december, the shadow affects the residential area on the other side of the A52, further analysis needs to be done and alternative form finding for the building, also orientation can be tested and new solar analysis undertaken.
Typical afternoon view over the south elevation, clearly showing intensive solar gain over the interior atrium and around the building. Solar energy sli-ghtly compromised by the low pitch angle of the faceted roof. Building could be brought back to the drawing board for further research on form finding to address issuess of roof pitch form and shading . Nevertheless, solar gain can be welcomed in cold winter days and help to reduce energy use.