In preparation for the building work we researched and set up an environmental preference schedule to help make conscious decisions in terms of sustainable selection of materials.
From a Design perspective we worked to knit together the existing physical charm and integrity of the buildings together with our needs and the energetic and environmental impacts to produce a practical and sensitive outcome.
During the Groundworks we reused as much hardcore and concrete as possible, crushing on site and minimised use of PVC in drains using almost entirely clay pipes; Chlorine from PVC being one of the worst greenhouse gases. With the wall construction we re-used bricks from a local demolition rather than using new and used lime mortar in the new build. The internal blocks used included a high proportion of recycled aggregate. In the ecoCafé, half of the walls are traditionally lime plastered.
Regards Heating and cooling, we used relatively high levels of insulation to achieve the following target U values: Roof 0.15W/m2, Walls 0.25W/m2 and floor 0.20W/m2, which are better than current building regulations.
After considerable discussion and compromise we reluctantly ended up using for practical and cost reasons 150mm of Kingspan seconds in the roof and more happily 140mm of woodfibre bats on the south walls.
Underfloor heating was installed in the ecoCafé to be heated by a Talbotts biomass boiler fed by chopped willow from short term rotation willow coppice grown on the farm.
We kept a reasonable thermal mass within the building by putting some of the insulation on the outside of the original barn. Thermal mass is required to reducing temperature fluctuations though the day that can happen in a building that is internally insulated. This together with night ventilation, which consists of low level vents on the North side and opening roof lights to create a chimney effect which can be opened when temperatures are cooler at night, will aid temperature control and cooling. We included wind lobbies on both main entrances to minimise heat loss from drafts and air changes maximisinge internal comfort.
The Timber was all sourced from FSC or managed forests and some, for instance the Douglas Fir ceiling is English grown. FSC stands for Forest Stewardship Council which is one of the main accreditation bodies that ensure that wood has come from a sustainable source. See www.fsc.org. The floors in the EcoCafe and WholeHealth were cut from reclaimed beams – the oak we were told from some old log cabins!Timber requiring treatment was treated with Borax based material rather than more conventional treatments as it is considered the least harmful.
With the Decoration we principally used Auro paints as they have some of the highest environmental credentials available. They are now available for sale within the ecoCafé where we are pleased to be their regional agents.
Finally, the lighting utilises principally low energy bulbs with minimal use of halogen bulbs, and maximum use of natural lighting wherever possible with roof windows and light tubes in the toilets.