CREATE Centre (http://www.createbristol.org/) is one half of a re-purposed tobacco warehouse built in 1908, that now provides office space for Bristol City Council, as well as numerous organisations working in the field of sustainable development. In addition, there is event & exhibition space, a café and a demonstration ecohome. The council’s Environmental Performance team is based within the building, and is part of the Bristol City Council Energy Service.
Features relating to energy include:
• The only Display Energy Certificate (DEC) “A-rated” building in the Bristol City Council estate
• Automatic meter readers for electricity and gas providing on-line half-hourly data
• Comprehensive Building Energy Management System allowing for weather compensation, zoned multiple occupancy temperatures and hours of operation
• Solar thermal panels providing hot water for the café
The building falls within the Bristol City Council EMAS system so is part of a corporate target to reduce carbon emissions by 3% year-on-year. Overall energy consumption has slightly reduced over four years – see Table 1 – Energy consumption reductions at CREATE Building, 2010 – 2014
Table 1: Energy consumption reductions at CREATE Building, 2010 – 2014
During that period there was a significant increase in the number of building tenants. Energy/ carbon intensity per tenant has nearly halved, representing a significant performance improvement – see Table 2.
Table 2: Energy intensity reductions per full time equivalent employee at CREATE Building, 2010 - 2014
Energy intensity per m2 has also improved – see Table above.
Table 3: Energy intensity reductions per m2 floorspace at CREATE Building, 2010 - 2014
Carbon emissions reductions are shown in Table 4.
Table 4: Greenhouse gas emission reductions per full time equivalent employee and m2 floorspace at CREATE Building, 2010 - 2014
The improvement in energy use per FTE was largely due to increased occupancy. The energy intensity improvements were otherwise due to a number of factors. The AMR and BEMS data was analysed to identify hours of operation, and relate it to known occupancy in different areas of the building. Bristol was able to reduce temperature and heating hours of operation (based on occupancy) without reducing staff comfort. “Observers” were recruited from each floor of the building to report on comfort at marginal times e.g. early in the morning and late in the evening.
Also, a programme of insulation including window seals and insulation of all heating and hot water pipes, saving an estimated 15 tCO2eq per year and solar thermal and solar PV were installed.
There is more detail below which demonstrate the methodologies mentioned in the Description section. Table 5 shows an example primary energy and consumption energy.
Table 5: Energy use and primary energy use (data from CREATE Building, Bristol City Council, UK)
Screenshots of half-hourly electricity and gas usage from a building management system control panel are shown in Figure 1.
Figure 1: Electricity and gas footprint reports from building management system control panel, CREATE Building, Bristol City Council (Ransom, 2014).
These screenshots signal in real time when energy use is becoming high and this can then be immediately investigated.
An example of annual degree day normalisation for heating, using the equation:
Annual total heating energy used/annual total degree day figure x degree days 20 year average
is shown in Table 6.
Table 6: Gas consumption and gas consumption weather corrected at CREATE Building, Bristol City Council (Ransom, 2014).
