Leah and Craig on Grand Designs: The Streets

Sustainable custom build wows on Grand Designs: The Streets

Leah and Craig opt for a bespoke prefab home after years of living in military accommodation

By Victoria Purcell | 11 May 2022

‘This is a super-insulated, ecologically minded, thermally efficient home,’ says Kevin McCloud after a tour of Leah and Craig Lewis’ Graven Hill custom build on Grand Designs: The Streets.

‘It isn’t a house of now, it is a house of 2035 or even 2050, because it is high performing, low energy and low carbon,’ he continues. ‘This is the kind of house we’ll all be wanting to live in in 15 years’ time. This is the house of the future.’

Leah and Craig's Graven Hill custom build from Grand Designs: The Streets

Leah and Craig’s Graven Hill custom build was influenced by their many trips to Bavaria. Photo: Lucy Yendell / Dan-Wood

Putting down roots

Leah and Craig both served in the army for many years, making it hard for them to put down roots. Craig left five years ago and now works in IT, whereas Leah, an army medic for 13 years, now teaches at a base in Oxfordshire.

This is their first chance to put down roots. After years of being posted overseas and living in military accommodation, where they often didn’t unpack fully, let alone decorate or even hang pictures on the wall, they decided to build something all of their own.

Inside Leah and Craig's Graven Hill custom build from Grand Designs: The Streets

Craig fitted the kitchen himself. Photo: Jacqueline Cross / Channel 4

A swift build

With their jobs keeping them busy, the couple decided to take a more hands-off approach to building their own home and opted for a prefabricated custom build. The process is simple – you can either choose a design right out of a brochure, or modify it to suit your needs. Each component – the walls, floors and roof panels – is then designed and built offsite in a factory, before being delivered to the site as complete timber panels ready for installation.

Leah and Craig commissioned Dan-Wood, which has built 30 homes on the Graven Hill site. The custom-build specialist is the biggest manufacturer of timber-frame turn-key energy-efficient houses in Poland, where it has two factories producing more than 2,000 prefabricated houses per year.

Their home, a two-storey, three-bedroom house with an airy, semi-open-plan ground floor, arrived on the back of a lorry from Europe. The large timber panels, complete with windows, doors, insulation, plumbing and electrical connections already installed, were lifted straight into place and slotted together. The shell of the house was built in a couple of days and the whole thing finished in a matter of weeks.

Bright and airy

Leah and Craig’s home, which cost them £502,000 in total for the plot and the house, is full of light and space. The kitchen sits at the front of the house with the living room to the rear, opening out onto the garden. A dining room and fitness area sit in the middle under a double-height ceiling with huge panels of glazing that drink in the light.

The statement timber staircase leads to an elevated walkway-style landing overlooking the dining area. At one end sites the master suite, which spans the width of the house and takes in views over a swale from three large windows. At the other end are two guest bedrooms and a bathroom. To the rear of the house, the couple have also added a garden office and bar.

‘For a custom-build, it’s as elegant and sharply finished a home as I’ve ever seen,’ says Kevin McCloud.

Leah and Craig's custom build from Grand Designs: The Streets

The bright, airy ground-floor space shortly after the build was completed. Photo: Lucy Yendell / Dan-Wood

Thermally efficient

Despite the huge panels of glazing and double-height ceilings, high-spec insulation keeps this EPC A-rated home warm. All Dan-Wood houses have energy-efficient heating as standard, using only 40-70 kWh per square meter a year, whereas the average UK homes uses 133 kWh per square meter a year.

Plus, the walls are encased in advanced OSB Superfinish ECO boards. Add to that a U-value of 0.148, which is less than half the maximum of 0.3 specified in current building regulations for England, Scotland and Wales, and this home is very thermally efficient.

Leah and Craig also chose to add an NIBE F2040 air-source heat pump which, supported by an NIBE EMO that converts energy from roof-mounted solar panels, provides all their heating and hot water. The house is also triple-glazed and has an MVHR unit installed.