Yaffle House

Project type: Residential
Project location: Wadhurst, East Sussex, UK

Yaffle House was a new-build house commission. The site was located in the East Sussex village of Wadhurst and was gleaned from the amalgamation of two strips of land between two detached properties, one of which being the clients’. Front and centre of the clients’ brief was to make the new house a low-environmental impact design in terms of construction and operational performance. It was designed towards Passivhaus standards with a thermally efficient building envelope and plenty of on-site energy generation.

Yaffle House is a super low-environmental impact new-build house which anticipates the needs of those wishing to live responsibly in the age of the climate emergency and which creates convivial conditions for life both inside and outside.

Key decisions about placement, orientation and form of the project were critical in this project. The design needed to resolve conflicting constraints of how to optimise beneficial passive solar gains and visual connections of the rear garden whilst avoiding overheating potentials which are always tricky on a south-westerly aspect. The southwest corner of the house is a total sun-catch and adding the pergola turned an inhospitable terrace into a convivial micro-climate whilst also protecting the glazing from low angle summer sun.

Design strategies included:

all-timber frame construction for optimising carbon sequestration;
super-insulated construction with wall, roof and ground floor u-values of between 0.10 and 0.11W/m2ºK;
triple-glazed windows;
super airtight construction;
mechanical ventilation with heat recovery;
meadow grassland covered flat roof;
a timber and steel pergola which can be adapted for summer and winter sun profiles;
4KW photovoltaic solar panels with optimiser and diverter to send excess electrical energy to the hot water storage tank;
ground floor underfloor heating throughout;
a pair of large rainwater butts for garden irrigation;
pre-wired for fitting of electric car charging point.

Design development

Being keen to avoid an interior of bland painted plasterboard surfaces, the interiors included wall and ceiling panels of softwood boards with a muted translucent wood stain to add texture, rhythm and colour. The ground floor was cast with a stunning polished concrete screed which should provide low-maintenance underfloor heated comfort for the life of the building.

The pergola design was arrived at after an exhaustive digital modelling exercise assessing different shading arrangements using software which accurately geolocated the project to reveal the shadow casting effects through the solar calendar.

Ian McKay worked on Yaffle House as ‘Director in Charge’ during his time at BBM Sustainable Design.