XCO2 Energy was appointed as the M&E design consultants for this exemplary building for sustainability and low carbon design in Raypark, Redbridge. The building is set to be a community building in the centre of Raypark consisting of a café, office and meeting space, music room and exhibition space.

Working with Sarah Wigglesworth Architects from the outset, XCO2 Energy provided environmental design guidance which helped influence the building design to address the specific site conditions and make best use of the free available energy in the local environment. All recommendations were analysed using environmental modelling software, and each one was optimised for cost, energy saving, comfort and CO2 reduction.

The thermal performance of the timber framed construction exceeds the requirements of Part L building regulations by more than half, and the use of robust detail greatly increases air tightness. The north-lit, profiled roof allows for diffused light without excessive solar gains. The resulting south-facing roof surfaces provide an ideal angle for the solar thermal array. The roof form also incorporates mechanical rooflights, which work as the high level extracts for the stack effect by drawing cool air in through low level windows in this mixed mode ventilation strategy. The passive cooling strategy is complemented by the use of high thermal mass partitions and floor coupled with night-time ventilation.

Negating the need for artificial cooling was achieved through the installation of an Earth Pipe ventilation system, providing supplementary free cooling and heating of ventilation air. The high moisture content of the soil made this system an ideal choice for the site. A heat recovery after the earth pipes produce a secondary heat exchange, recovering heat from the exhausted stale air. The tempered fresh air is then fed into the space via a displacement ventilation, removing stale air and odours at source and helping promote the stack effect in the building during mixed mode operation.

The daylighting design delivers an even distribution of light throughout the space and reduce the need for artificial lighting. Daylight should be adequate for 70% of the opening hours of the building, and artificial lighting utilising presence indicators and daylight dimming control should meet the lighting requirements for the remainder.

Solar thermal evacuated tubes generate 50% of the annual hot water demand. A biomass pellet boiler provides space heating and the remainder of the domestic hot water demand, with pellets sourced from Northern Ireland. Air quality in the park will not be affected by the biomass boiler due to the exposure of the site and the low population density making the location favourable for solid biomass fuels.

XCO2 Energy will be carrying out detailed post occupancy evaluation of the building after completion. This will provide the team and client with valuable information on the true benefit of all environmental proposals, and also feed information back to further improve our design process.