Rural Durham home mixes thoughtful design and passive aims

Architectural technician Philip Newbold of New Bold Design describes how he overcome strict planning rules and a tight budget to build his sensitively designed, super low energy home in an area of outstanding natural beauty.

My wife Joy and I sold our leaky Victorian home in 2008 and started looking for a plot to build our own low-energy house. In 2011, shortly after I was made redundant from a senior associate’s job with a leading architecture practice in the north east, we found a plot in Upper Weardale with what we thought was detailed planning consent. In fact it turned out the planning consent had expired in 2009. The seller had to re-apply, but we finally secured ownership of the plot in January 2012 for £70,000.

The timber frame being erected

I had used some of my redundancy money to train as a passive house consultant and as we now had no significant income, we decided to use all the money we had to build a passive house, so that we would not have any major heating bills in future. We originally planned to build without a mortgage but in the end we needed £65,000 from the Ecology Building Society and £10,000 from the Bank of Mum and Dad just to make the house complete enough to live in. The total build cost so far is around £180,000.

The plot is 345 square metres and the village is in a conservation area on the river Wear. When we opened discussions with the plan- Rural Durham home mixes thoughtful design & passive aims ners on the 15 conditions, we found they were inflexible and not really interested in our aspirations to build a passive house. Thanks to draconian planning restrictions, out went any hope of being able to build a certified passive house. While I had hoped to build a more compact, cubic house, the planners insisted we conform to the Dales cottage vernacular of an L-shaped dwelling plus a lean-to extension.

Our new home is a two-storey detached house of 116 square metres (over two floors) with a non-habitable attic plant room and store. The ground floor comprises an open-plan dining hall and kitchen, lounge, WC, utility room and store. The first floor has a master bedroom, study bedroom, bathroom and WC, guest bedroom with en-suite shower and WC, and linen cupboard. The attic plant room and store houses the 250 litre hot water tank and the MVHR unit.

We started work in March 2012 and moved to a small, rented cottage next door to the plot. It didn’t stop raining (or snowing) for about 10 months, and 2012 turned out to be the wettest summer for 100 years.

Smartply OSB lines the internal face of the timber frame, with the joints sealed with Tescon airtightness tape

We cast the concrete floor slab over 450mm of EPS insulation in June. As the timber frame was erected, I inserted continuous Intello membrane with taped joints around the perimeter of the upper floors and roof in order to ensure good levels of airtightness. All the drain pipes and services penetrations through the floor slab and external walls were fitted with airtight grommets.

The planners had initially insisted on double-glazed, sliding sash windows, but I was able to persuade them to accept triple-glazed, mock-sash, tiltand- turn casements with a U-value of 0.9. By September 2012 the roof structure was watertight, but just as the rain turned to snow, the windows and doors arrived from Lithuania, some weighing up to 70kg each. I applied special airtightness tapes internally and externally to all the frames before getting a local joiner to help install them. The same joiner helped me to line the internal face of the timber frame with Medite Smartply 18mm OSB 3. We then primed and taped the OSB joints with Tescon tape using a heat-gun to dry the joints.

I also taped the joint between the OSB and the ground floor slab. When all the airtightness measures were complete, the blower door test gave a result of 0.59 air changes per hour. Using local stone, the stonemason managed to get the external stonework up to the ground floor window cills before the first serious snow arrived in November. As the coldest and longest winter for 50 years followed the wettest summer, progress on the stonework almost ground to a halt.

The internal OSB was lined with battens to create a 50mm services zone for pipes and wiring. After all the services had been installed, the void was filled with 50mm PUR insulation board before a final lining of 12.5mm plasterboard and skim was added. In spite of incomplete stonework, no stove and no slates on the roof, we moved into the house in February 2013. We then installed a room-sealed wood-burning stove in the lounge with a back boiler that provides up to 8.5kW to hot water in the winter and also heats towel rails in the bathrooms and a heat-leak radiator in the linen cupboard.

After all services had been installed, the void was filled with 50mm PUR insulation board

We have no central heating system beyond the wood burning boiler stove and the house is maintained at a minimum of 20C. Solar thermal panels provide most of the hot water in the summer, topped up with the immersion heater, assisted by the output from our 1.5kW solar PV array.

We discovered that we could not get the feed in tariff for the solar PV until we had an energy performance certificate. But we could not get an EPC until we had a completion certificate from the building control officer. And we could not get the completion certificate until the stove flue, stonework, roof slates, electrics and rainwater goods were finished. This was finally achieved in October 2013, with the EPC giving the house an A rating.

As the house nears completion and we have occupied our new home for over a year, we are beginning to appreciate what all our hard work has achieved. We only need the stove burning on winter evenings and have no other fuel bills apart from electricity which is currently running at £35 a month, excluding the feed in tariff. The silent MVHR system recycles the heat generated inside the house while providing filtered, fresh air. There have been no overheating problems so far.

Despite costing around £250,000, the house is only worth £225,000 according to the Royal Institute of Chartered Surveyors, so building a one-off house like this in the UK is still too expensive. The clever components have to be imported and our workforce is just not good enough. The hybrid heating and hot water system is difficult to control and both solar systems have had technical failures.

A continuous Intello membrane with taped joints around the perimeter of the roof ensures good levels of airtightness

But we have managed to self-build a Band A home to the cusp of passive house and have a warm, comfortable home in which to live and work without any significant heating bills. More importantly, we have proved that it is possible to build a real low-energy home in a conservation area, and an area of outstanding natural beauty (AONB), which fits in with the local architecture while addressing fuel poverty issues head-on. One day, all houses will have to be built like this.

Greendale Cottage was recently awarded the price for best individual new home at the 2014 Northern LABC Building Excellence Awards, and will go forward to November’s national awards in London.

Selected project details

 Design & project management: New Bold Design
Client: Philip & Joy Newbold
Timber frame: Swift Timber Homes
Windows & doors/MVHR: Green Building Store
Airtightness products: Pro Clima
Solar thermal: Baxi
Solar PV: Panasonic
Mechanical contractor: Pure Energy Systems
Airtightness tester: Apex Acoustics
Cellulose Insulation: PYC Insulations
PUR insulation: Quinn-therm
Floor insulation: Springvale
Basalt wall ties: Ancon
Stone cladding: Dunhouse Quarry Co
Wood burning stove: Stoves Online
Towel radiators: Best Bathrooms
Reclaimed roof slates: Reclamation Supplies
Finance: Ecology Building Society

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