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Set in the tiny hamlet of Gorstan in the heart of the Scottish Highlands, Tigh-na-Croit – a fully-certified Passivhaus dwelling built with meticulous attention to detail, and rigorous design and construction – nestles on former crofting land.
The brief to designer HLM was fairly straightforward, but its execution was particularly challenging – to create a quality modern and low energy Passivhaus from which its clients could enjoy their love of outdoor pursuits while also living in an environmentally responsible, lowimpact home.
HLM was determined that the house echo the form of a traditional steading. It proposed a contemporary architectural solution where the scale, proportion, openings, roof pitch and mix of materials are all contextually relevant to the rural landscape.
The house has a generous living space, kitchen and dining room, three bedrooms, utility space, cinema room, sanitary, utility and storage space. The living areas face south, making the most of views, with a small terrace. HLM’s primary challenge was to design a building that would satisfy the high energy efficiency dictated by the Passivhaus standard.
The design signifi cantly reduces energy consumption while ensuring excellent internal comfort conditions throughout the year. It does this with a combination of careful orientation, a compact simple form, high levels of air tightness and a superinsulated building fabric.
The innovation doesn’t end there. A balanced MVHR (mechanical ventilation with heat recovery) system is radically reducing heating bills and providing cleaner, fresher quality indoor air. Hot water is provided from regenerative sources via an air source heat pump with provision for a photovoltaic (PV) system sometime in the future.
Certification was carried out by the Passivhusbyrån in Sweden, a Passivhaus Institute accredited certifier. It confi rmed impressive performance, including; 97 kWh/ sq m/ annum of primary energy demand; 15 kWh/sq m/ annum of heating demand; 13.4 W/sq m of heat load; and an air pressure test after completion certified 0.6h-1 of airtightness.
The primary material for the house is white render, with limited areas of stained timber cladding used at the dining room ‘box’ on the south elevation and small areas to the north and west elevations. Glass also features heavily, allowing the framing of particular views and maximising the potential of passive solar gains as part of the Passivhaus design philosophy.