Curves in all the right places

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Not only have Roger and Lucy Southcott achieved their ambition of building a home that’s energy self-sufficient with super-low greenhouse gas emissions, they’ve also created something that’s carefully shaped to fit the contours of its Wiltshire location


In one sense, Roger and Lucy Southcott’s self-build could be seen as an opportunity for them to practise what they preach. After all, he works in sustainable housing development, while she’s an environmental consultant.

It should be no surprise therefore that this project represents the realisation of a long-held ambition to build something for themselves that is self-sufficient in terms of its energy needs, and offers super-low greenhouse gas emissions.

But of course it’s also an exciting new chapter in Roger and Lucy’s lives – one where they’ve swapped life in a Victorian mid-terrace property in London’s Bermondsey district for a unique and very 21st century home in Wiltshire with views of Salisbury Plain.

Says Roger: “I was getting tired of living in London – it can be aggressive, dirty and noisy. We wanted to try to deliver on what we both believe in terms of sustainability, but we also wanted things like more space to live in, a kitchen garden and a semi-rural location.”

Achieving their self-build ambition took time and wasn’t always without challenges. The first task was finding land to build on. The couple set their search zone to the west of the capital and spent several years looking online and driving to a lot of potential plots. Nevertheless, says Roger, the time and the travel is worth it: “Never buy without visiting the site and read between the lines on adverts. If a plot seems cheap, there’s a reason.”

The site the couple eventually bought was on the edge of the small town of Westbury. Purchased at auction in 2014 for £200,000, it already had a single-storey four-bed bungalow on it. Roger advises: “It’s definitely worth considering land with an existing property that can be demolished, but factor in the cost of demolition and removal of spoil.”

The bungalow was rented out for the next 18 months while the final terms of planning permission were negotiated and designs for the new build were drawn up. Roger says: “It is possible to talk to planners before submitting an application and it’s well worth it for the advice they can give in terms of what may or may not be acceptable. I’d also recommend engaging with the neighbours early in the process – explain your plans.”

As for design, Roger laughs when he thinks back to the first ‘drawing’ he did himself – on a napkin in a pub. “We took the napkin to our architect, Simon Radclyffe, but asked him to come up with challenging alternative designs that would encourage us to think about what we really needed from a house and how we would live in it. Overall, the design ethos was for something unique but as sustainable as possible. Of course, the final look of the building was nothing like the napkin sketch!”

One idea that did survive from Roger’s original vision was that of a circular hallway. Not only is the hallway – which is rendered beautifully with slipped slate – probably the most striking feature of the building, its curves have also been echoed across the rest of the exterior design of the Southcotts’ new home.

Roger says: “The whole building is curved. Our architect felt the house would fit into the sloping site better if it was curved and he was right. What’s more, if you stand at one end of house you can’t see the other end because it’s round the corner. This gives the whole house a more interesting feel – less predictable, and unique. I do like the idea that there isn’t another house the same as it in the world.”

While the couple are perfectly content with curves, Roger does add a note of caution: “Curved does mean extra work, and it can add to the cost. There are some smaller practical issues too – standard curtain poles, for example, won’t go round a curve!”


A much bigger headache than curtain poles that presented a very serious problem early in construction was an argument over contractual obligations with the company meant to install the engineered timber frame of their new home. Roger explains: “They threatened to sue, we threatened to countersue and everything stopped onsite for two months. The cost of the timber frame was £30,000 so there was a lot at stake.”

The couple eventually settled out of court, paying an extra £2,000 to get everything back on track. Reflecting on the row, Roger’s not sure the couple could have done much more to avoid it. “We thought we had everything tied down watertight by using a standard JCT (Joint Contracts Tribunal) contract but got involved in an argument over semantics.”

Despite this experience, Roger still recommends using this form of contract:

“Some companies don’t want to work to a JCT because they see it as restrictive, but in most cases it should offer protection both for you and the contractor.”

Other delays in the construction process for the Southcotts included dealing with nesting bats at the site, which cost more than £7,000, and an archaeology dig that meant a bill for double that amount. Says Roger: “We had to dig the entire site to a one metre depth. They did apparently find a Romano-Anglo Saxon lime kiln. The experts looked at it and then filled it in again. It was a total pain and took months to do.”


These bumps in the road aside, Roger and Lucy are delighted with their self-build, which had the finishing touches to the internal fit out applied during 2019. With a footprint 20 per cent larger than that of the bungalow that preceded it, the new structure responds to the sloping site by

having three storeys on its eastern side, including a basement level that is partially underground, and one storey on its western side. Roger is understandably very pleased with the circular hallway: “It’s amazing,” he says. Two spiral staircases within the hallway give access to the basement and the first floor, while a feature chandelier is another attention-grabber in this impressive space.

At basement level the house has two bedrooms and a bathroom, the garage, a plant room and two store rooms. On the ground floor is the front door and entrance to the hallway, plus a toilet, dining room/kitchen area, a living room, a study and an extended balcony area. Finally, a bedroom, bathroom and dressing room can be found on the first floor, bringing the total floor area to 350 m2. Ticking another box in the Southcotts’ wish list, both the ground floor and first floor offer views out onto Salisbury Plain from the south-east aspect.

Besides the aforementioned slate, the exteriors are finished in a white render and larch wood. Roger says: “We wanted a house with some natural features, but also crisp, clean and modern.”

Of interest for other self-builders whose projects also include building underground, the Southcotts’ basement uses insulated concrete forms (ICF) with 300 mm Kryton waterproof concrete infill, negating the need for tanking to protect against water ingress.

And for those self-builders who are considering flat or nearly flat roofs, Roger and Lucy decided to opt for a Sarnafil single ply membrane. Says Roger: “It’s a material that’s much lighter than tiles and can be unrolled and fixed to the roof quickly, speeding up the process of making your home weatherproof. We did look at zinc as an alternative but we couldn’t afford the price!”


With Roger and Lucy being keen believers in eco living, sustainability was always going to be a major factor in their self-build. The height of the hallway, for instance, doesn’t just make for a grand entrance, but is also a critical component in the passive stack ventilation system the couple have installed.

“We could have installed mechanical ventilation,” says Roger, “but we weren’t keen on that kind of intervention to help the house breathe properly – we wanted minimal ‘kit’ so that the house wasn’t run by computers.” He explains how the approach they took is long established: “Passive stack ventilation, using the prevailing wind to take away hot air from high- level vents, has been used very successfully in other, hotter parts of the world for centuries.”

To help achieve the low energy targets for the house, the timber frame of the house was installed with 300 mm Warmcel cellulose insulation, which is made from recycled paper. In addition, the house has a cold roof system, again featuring 300 mm of insulation, while the timber-framed windows are triple glazed.

The roof has been fitted with 32 solar photovoltaic panels with a potential output of 10 kW, providing more electricity than Roger and Lucy need on most days. Overnight, the house runs off surplus energy stored by a Tesla battery. All of these measures mean that while the basement does feature a gas-fired wet heating system with radiators, the only heating above this level is provided by a wood-burning stove.

Another investment in sustainable technology is the 7,500 litre rainwater harvesting tank buried in the garden. A pump takes the water gathered there back into the house, where it is used to flush all the toilets and supply the washing machine. However, the couple do have the option to switch to mains supply in the event of a prolonged drought.

The other sustainable choices the couple have made in their self-build include a porous resin driveway (to counter flooding) and LED lighting throughout. Teak wooden flooring from the bungalow has been relaid in the new property and windows from the bungalow will eventually be used for a new greenhouse. Says Roger: “We’re happy with the green credentials of the new house – we’re pretty proud of what we’ve done.”


Looking back on their self-build journey now, Roger does think that his professional contacts within the housebuilding sector was an advantage: “I know contractors, what they do, their prices and track record and I was able to use that to get what we wanted.”

Nevertheless, he and Lucy did learn some lessons the hard way. He says: “In hindsight we would have been more present throughout the build process. We did hire a project manager and he was very good. However, the devil is in the detail, and many things could have gone more smoothly and snags been caught
before they became problems had one of us been onsite.”

Besides the costs already mentioned, the bill for professional fees and construction came in at close to £1.2m. The couple used savings, inheritance money and the proceeds from the sale of their London house to fund their self-build, and are now debt-free.

Roger says: “It’s a dream come true and the whole project has been a real passion for me. We now have a house built around what we want and which is suited to our lifestyle, rather than something that a construction company thinks we need.”