Nestled in the North Somerset countryside sits a new timber-frame four-bedroom family home. DHV Architects have created an impressive, highly energy-efficient home with an A-rated EPC, clad with highly durable Brimstone cladding.
Previously occupied by a dilapidated chalet bungalow, the site is on a hillside with expansive views over the Mendip Hills. The house is a south-facing two-storey volume featuring a large open-plan kitchen and dining area on the ground floor, with four bedrooms arranged across the upper level.
The cladding is Brimstone, a thermally modified ash derived from UK woodlands. It is certified to Durability EN350-2 Very Durable (Class 1).
The living areas open onto a patio offering uninterrupted 180º panoramic views from the rolling farmland of the east to glimpses of the Bristol channel to the west.
A single-storey outrigger extends from the western end of the building, reaching out into the landscape while providing acoustic shelter for the terrace from distant road noise. A cantilevered canopy extends over the outrigger’s extensive glazing, offering protection from solar gain and contributing to indoor thermal comfort.
Clad with thermally modified ash
The elevations feature cropped limestone and Brimstone timber cladding – a thermally modified UK ash – supplied by TDUK members Vastern Timber. The limestone and timber are punctuated by brightly coloured render panels.
The client and architect visited a local site, where the builder had used Brimstone cladding, and were impressed with its appearance. The cladding has now been in place for approximately 16 months. Its rich, full colour has weathered only subtly; change in appearance has been minimal.
Energy efficiency and building fabric
Achieving a level of energy efficiency exceeding standard regulatory requirements was a fundamental objective of the design brief. The external walls are formed using timber frame, with a continuous layer of insulation positioned externally to the structural envelope.
The south facade is characterized by a prominent stone chimney and a linear shading pergola above expansive sliding doors.
This insulating layer wraps seamlessly around the floor, walls and roof, contributing significantly to the building’s thermal performance.
The windows are triple-glazed composite units, featuring timber frames with durable aluminium outer casements. Attention was paid to airtightness, with each junction carefully constructed by the contractor to minimise gaps.
A mechanical ventilation system with heat recovery (MVHR) provides continuous fresh air to all habitable spaces. A low carbon heating system (air source heat pump), on-site renewable energy generation (8kW of solar PV panels on the roof) and batteries enable the home to achieve an A-rated EPC.
This article appears in issue 10 of Designing Timber magazine
