eco-house-5D-9164Purpose built eco-house built on the Passivhaus or Passive-House methodology requires little additional heating, relying on sunlight and body heat. Photo: ©Graham Riddell Photography High on a hill over-looking the stunning Tweed Valley in the Scottish Borders, sits a remarkable open and spacious building that harvests energy from the surrounding elements, maintaining a constant and even temperature throughout primarily from natural sunlight and radiated body heat from its occupants.

Built in 2010 on land bought from the Forestry Commission, the house became a larger project than the original barn ruin the clients were planning on converting. They employed the skills of a firm of specialist green architects, Gaia Group in Edinburgh who quickly realised the site had more potential and the seeds of a larger project were sown. By utilising a more elevated position than the existing structure, the architects envisioned a unique project, one that would push to the limits of what could be achieved for building an environmentally sound, ecologically friendly, three-bedroom home.

Recommending the Brettstapel concept (after German engineer Julius Natterer), where only wooden dowels are used throughout the construction, avoiding the need for any nails or glue, they could build a Passive House or 'passivhaus' with exceptional airtight properties where most of its heating is generated from the natural elements and body heat of its occupants. The interior climate is evenly circulated by a mechanical heating and ventilation system (MVHR) that draws air into the structure and circulates it throughout before returning the air back outside. In winter some additional internal heating is required (such as a log burner) to heat the incoming cold air which then heats the cold air coming in when it is returned after the recycle process of approximately three hours.

The required standards of construction for such a building are therefore far superior to conventional building methods utilising perfectly sealed, pre-fabricated sections manufactured in Austria and then transported to the site for a six-week construction window. 

The clients were sold on the concept and readily agreed to create not only a beautiful home, but an architectural icon which would go on to win the Scottish Homes award for Architectural Excellence in 2012 and achieved level six in the government's code for sustainable homes – the highest rating there is for energy efficiency.  
 

eco-house-5D-9130The South facing orientation of the house ensures maximum light for solar capture. Photo: ©Graham Riddell Photography eco-house-5D-9162West side elevation looking down over the Tweed Valley with walkway from top floor to the outside and the solar nature panels on the roof.

eco-house-5D-9157The main drive leads up to the North facing entrance. Photo: ©Graham Riddell Photography Occupied since 2011, the owners have to date enjoyed idyllic peace and tranquillity and whilst there were a few initial snags with their hot water storage from the innovative rooftop solar panels, they have otherwise lived trouble-free. The exterior cladding is constructed from untreated European larch, secured from sustainable local forests which when installed were more of an alarming orange colour but which have thankfully settled down to a weathered 'silver' grey and now blends stealthily into the surrounding hillside. The walls are almost a foot thick (250mm) and filled with wood fibre and resin insulation which provides exceptional protection from the elements. The stone work is from local quarries and adds aesthetically to the natural-elements of the design, breaking up the essentially wooden structure to provide contrast and texture to the overall appearance and which blends the entire house back into the surrounding landscape.

The orientation of the building is south facing, ensuring maximum exposure to natural daylight where the roof's solar panel system and the triple glazed windows can perform at their optimum.

eco-house-5D-9145South-facing patio and balcony provide ample space for outside relaxation. Photo: ©Graham Riddell Photography Internally, the living environment is bright and spacious with high quality finishes throughout. The hand-made doors are almost twice the thickness of standard doors and the triple glazed windows seal the elements from the outside. Large areas of glass throughout the design, especially on the south-facing side, ensure heat is transferred into the building, acting like a heater. If too much heat is generated, it can be controlled by electrically controlled external blinds which unlike internal blinds, prevent any heat from entering.

eco-house-7D-9170Heavy, thick oak and spalted beech doors (downstairs), ash and birch upstairs. provide highly effective sound proofing and insulation. Photo: Graham Riddell Photography eco-house-7D-9170Triple Glazing for extra insulation. The ample living space is located downstairs whilst the bedrooms and bathrooms are on the upper floor where extended views out over the landscape can be enjoyed. All interior walls are made from locally sourced European larch, the floors in oak and larch were fitted by local tradesmen. The furnishing detailing was supplied by Ancrum based Real Wood Studios where the sumptuous feel and look of their work adds greatly to the wholly natural effect.

eco-house-7D-9162Hand crafted cupboard doors supplied by Real Wood Studios, Ancrum. Photo: Graham Riddell Photography eco-house-7D-9164Free-floating oak and larch flooring planks are secured with batons and screws. First and foremost, this building is a home. The light and airy feel throughout the interior affords spacious living which is as relaxing as it is appealing. All the rooms have clay-based wall sections which help to control humidity and prevent condensation. They also prevent monotony by adding areas of contrast to the rich wooden interior. The main hall and open plan kitchen have a solid base of Caithness slate, whilst the rest of the house in decked throughout with free-floating oak and larch boards that are secured in place by secured batons, screwed down to hold everything snugly in place. The abundance of insulation under the roof and below ground is over a metre in depth and the walls are about 250mm thick, ensuring heat is retained and the cold cannot penetrate.

eco-house-5D-9115-6Open plan hall with lounge (left) and kitchen leading off. The stairs, and two further study rooms at the rear of shot. Photo: ©Graham Riddell Photography eco-house-5D-9123-24Large lounge area with white clay wall sections and wood burning stove. Photo: ©Graham Riddell Photography eco-house-5D-9119-21Open plan kitchen/diner leads onto patio and has utility at rear. Photo: ©Graham Riddell Photography eco-house-5D-9126Staircase leads to the upper floor with three bedrooms, two bathrooms and a seating area overlooking the balcony. Photo: ©Graham Riddell Photography

eco-house-7D-9158Seating area overlooking the balcony and towards bedroom. Photo: ©Graham Riddell Photography eco-house-5D-9127-29Example bedroom clad in larch wood with views over the valley below. Photo: ©Graham Riddell Photography My overall impression of this magnificent property was one of awe. From the quality feel of the internal fittings to the enviable location in a beautiful part of the Scottish Borders where homes like these should feel welcome. It was as far from the creeping housing estate mentality which is becoming so prevalent in our border towns, as new developments bring city housing estates to our rural landscapes.

It would be great to see more empathic design which embraces the beauty of the natural area by featuring more elements taken from this iconic example.

Graham Riddell

June 2019