Blue Bell Centre
The full case study of the Blue Bell Centre is available to download here.
John Whitehead, Renova Developments Ltd.
Building type, sector and stage
Non-domestic , new build, health, in operation, North West
Air-source heat pumps, under-floor heating, solar thermal, rain water harvesting, health centre
The Blue Bell Centre is a new 2,500 m² health centre for Renova Developments on a busy junction, on a main route into Liverpool. The building was completed in June 2010 via a design build contract, under a Local Investment Financial Trust (LIFT) framework. The main lease is with the Primary Care Trust, whom subsequently sub-let space to four individual General Practices. The ambition from the outset of the scheme was to be one of the first healthcare buildings to achieve a BREEAM Excellent rating, with exemplary low energy use, low operating costs and significant CO2 savings. The design predicted a 20% total energy requirement of an equivalent health care building, saving £30,000 annually on energy costs. The design team started with stringent air tightness target of 5 m3/m2/hr @ 50Pa, in excess of regulatory requirements. High levels of insulation were adopted and reflected in a low predicted heating demand, which led the design team to move away from traditional fossil fuels to electrically driven air source heat pumps. This ultimately resulted in a mechanical strategy that was all electric. The building is mechanically ventilated with heat recovery from exhaust air, with passive ventilation in central atrium. Other sustainable features include solar thermal for domestic hot water, rain water harvesting system for toilets and green roof to increase biodiversity.
Although the air tightness target has been achieved testing at 4.41 m3/m2/hr @ 50Pa, initial energy analysis indicates consumption over twice initial targets, which is supported with a DEC rating of D. A share of this can be attributed to the omission daylight sensing in the lighting system that was initially in the design, resulting in all central space lighting remaining on despite good daylight. A lack of control of the hot water system was another factor; with the backup immersion heaters leading the solar thermal and supplementary heat pump system. This is compounded with the fact the solar thermal array is not optimised in orientation and mounting is flat as opposed to a 30° tilt.
The early stages of the study have already initiated corrective measures, such as alteration of hot water production routine, which is showing beneficial effects on energy consumption. The continuation of the BPE study will provide the best possible opportunity for the scheme to be an exemplar healthcare building in operation and match the high design ambitions.
Key Performance Indicators
|Project cost||£5.7 million|
|Floor area (GIA)||2500 m2|
|Air permeability||4.41 m3/m2/h @ 50Pa|
|Building regs estimate of CO2||13.6 kgCO2/m2/yr|
|EPC rating||B (37)|
|DEC rating||D (98)|
|Measured electricity use||143 kWh/m2/yr*|
|Measured CO2 emissions||79 kgCO2/m2/yr*|
|Total CO2 emissions||208, 975 kgCO2/yr*|
|Occupancy pattern||Full tenancy, 56 staff|
*Estimated from initial meter data (full meter reconciliation to be completed)