SIPs home aims to be off-grid exemplar for sustainable development in Northumberland

“Whilst the project is still partly an experiment, our objective is to minimise the impact of our build on the environment by using renewable/recyclable materials as well as relying solely on solar and wind energy for power.” Peter Mouncey.

After spending much of his working life considering how to embed sustainability into other people’s lives, architect Peter, together with his partner Diana decided to leave Newcastle city living behind to build a brand new, sustainable bungalow in the beautiful Northumberland countryside.

With one eye on retirement and a dream to create a home and lifestyle that fully embraces sustainability, the couple set about looking for a plot or conversion opportunity that would allow them to build an experimental off-grid home that will be seen as an exemplar for sustainable development in rural Northumberland.

Eventually finding the perfect rural plot within open countryside, on an elevated north facing slope that overlooks Hadrian’s Wall, the couple’s 1.5 storey, four bed home is halfway between Newcastle and Carlisle on land that was formally for summer grazing.

After researching construction options for this ambitious self build and looking back at projects previously designed and constructed by work colleagues, building with Structural Insulated Panels (SIPs) seemed to be the best way to achieve both the degree of airtightness and speed of build required. Peter was keen to reduce the risk of the timeline being disrupted by bad autumn/winter weather.

Set just outside the Northumberland National Park and UNESCO World Heritage site boundaries, where new developments would not normally be permitted, the couple were fortunate in being able to rely on an historic planning permission for the principle of the development on the site. They worked closely with the local planning authority (LPA) to agree an appropriate approach to the scale and appearance of the new design within the context of the open countryside and buffer zones to the protected landscape.

Self building in this exceptionally rural location was always going to have its challenges for construction and deliveries but the off-site precision engineering of SIPs meant it was the ideal build solution for this project.

With the plot only accessible via one single track road with a difficult 90° turn going up the hill, the large articulated lorry deliveries which carried the SIPs panels had to be offloaded at the bottom of the track and then taken by flat trailer, towed by a pickup truck, onto the site. This would not have been possible with traditional methods of construction.

Taking design inspiration from sustainable projects Peter had previously worked on together with his contemporary interpretation of the local vernacular buildings, the couple’s new home has 300m2 of internal living floorspace plus a 50m2 garage.

“Having become used to the generous proportions of the rooms in our Georgian terraced house, we were keen that the rooms in our new home were of similar scale” said Peter.

The couple’s SIPs self build, now known as Westfield, is built using 142mm Kingspan TEK panels and makes the most of the design flexibility provided by SIPs. It has double height living spaces, mezzanine levels and a room in the roof to promote an overall impression of spaciousness.

Peter and Diana’s new home gives them fantastic views of Hadrian’s Wall and the surrounding countryside, so the couple have tried to frame key views through windows and with internal layout. A major influence on the layout was to maximise the south facing glazing for both light and passive solar heating. They have added an oriel window which offers expansive and impressive views across the Northumberland landscape and beautifully connects the inside and out. A real WOW factor for visitors.

They have created an airtight building envelope with triple glazed windows and renewal energy sources including an MVHR system, 6.4kW of solar panels plus a 3kW wind turbine with a lithium battery to smooth out the differences between supply and demand for power. All of which are powered on site. The new SIPS home also has a freestanding 3kW bio-ethanol stove which burns the waste product from sugar beet processing and only emits a small amount of CO2 / H2O - so low that there is no need to vent outside.

By utilising smart monitoring technology, the clients measure and attain their low energy targets, compiling the information in order to share with people with similar nett zero ambitions. Recent data showed that in one day they avoided 14kg of CO2, the equivalent of planting 1 tree.

With an impressive set of SAP results, (EPC rating of A and an air tightness test of 0.6m3/hour/m2 at 50Pa) Westfield is testament to building with SIPs. In fact, the test results were so good that the test had to be done twice to validate the results!

The house has a 32.5° pitch VMZINC Zinc standing seam roof, vertical Siberian Larch cladding to the walls with VMZINC cladding panels below the windows, every element of this new self build homes has been carefully and tastefully curated.

With his architectural background and in-depth construction knowledge, Peter was able to not only design and project manage this complex build but he also did much of the construction work himself.

“Self building at the time we did, presented us with a unique set of challenges” said Peter.

“Like nearly all construction projects undertaken over the past few years, we had to deal with COVID restrictions and the resulting shortages of labour and materials. Yet, through what was a very challenging time, we did have some high points.

“One of the most significant being the completion of the SIPs enclosure, which gave us our first real reassurance that the internal spaces and relationship to the landscape were consistent with our vision.

“Although the project took us longer to complete than envisaged and some elements were significantly more expensive than originally planned, we managed to keep the overall project costs within our original budget.”

The couple’s environmental ambitions extend to the land around their new home, creating a wildflower meadow and wetland area to improve biodiversity on the site, as well as new tree and hedge planting to improve connectivity to wildlife.

Peter and Diana’s dream of creating a sustainable lifestyle that minimised the impact of the build on the environment by using renewable/recyclable materials as well as relying on solar and wind energy only, has now become a reality and they couldn’t be more proud of what they’ve achieved.

“We hope that housing developers will support more sustainable and better designed homes and people who want something unique should not be daunted by commissioning or building their own home” said Peter.

Westfield is a shining example of what can be achieved with vision and passion and is testament to building with SIPs.  When asked if there was anything he would have done differently - Peter replied "Yes, I wish that I had done it earlier!