The Tea Cosy Effect

Reflecting on our sustainability philosophy..............

Is it really 17 years ago the little Eco House in Wichelo Place in Brighton was completed, achieving a BRE ‘Excellent’ rating in energy saving and carbon reduction ? (and later winning the Daily Telegraph Eco House of the year, a Sussex Heritage Trust Award and numerous others).

In a time when the net zero focus is on everyone’s radar, and reflecting on our eco house from yesteryear, our approach to sustainability still remains relevant, not as an add-on but as integral to the design process, utilising passive design principles and strategies from project inception. We call this ‘the tea cosy effect’ and for us this includes:

•High levels of thermal insulation and air tightness with limited cold bridging to the external envelope (the tea cosy) // •High level of internal thermal mass (the tea pot and tea). Solid floors rather than timber, solid partitions rather than timber stud and a ‘solid’ inner face of external walls. Internal thermal mass regulates internal temperatures (a cave has a constant internal temperature no matter the season).

Other passive design measures also play their part:

•Orientation– South facing main glazed façades to increase winter warming through solar gain and limiting north facing glazing to reduce heat loss in the winter. // •Solar shading–shielding south and west facing glazing to reduce solar gain in the summer. // •Natural ventilation to achieve summer cooling. We believe homes should be naturally ventilated to provide summer cooling (energy consuming ‘air conditioning’ has no place in good design). During the early design phase we undertake thermal modelling of the proposal to simulate how the building will perform during different seasons and design the size of opening windows and roof lights to ensure the building achieves sufficient air movement for occupancy ventilation and overheating mitigation.

Getting these simple passive design principles right at the early design stage significantly reduces the ‘active’ sustainability measures required to reduce energy consumption of the home. We also believe that a good ‘sustainable’ building does not have to shout out about it by having every bit of technology ‘on display’.

Comparing two case studies from our portfolio, there are of course significant aesthetic differences between the Wichelo Place house and the Beach House at Shoreham (completed last year), but our underlying sustainability philosophy remains the same now as it did 20 years ago. In terms of construction materials, the main difference between the two projects is the former was built utilising timber frame for the external walls whereas for the latter we specified ICF blocks made from recycled timber pallets and (now readily available) cement free concrete is pumped into the ICF blocks and used for screeds and foundations. Locally coppiced sweet chestnut remains one of our favourite cladding materials.