A flat pack future

Building flat pack housing off-site has the potential to transform both the energy performance and affordability of new rural developments.

That is the vision at the Barlavington Estate in West Sussex, where owner Sir Sebastian Anstruther is working with architect Bill Dunster to design and build homes that are environmentally and financially sustainable.

Bill, whose company ZED power specialises in zero-carbon housing, has developed the ‘ZED in a box’ concept working with a local delivery team. Essentially a kit of parts, it cuts down on build costs and improves energy performance, made in a barn on the 3,000-acre estate.

The ‘tiny house’ version is 250 square feet, with the supply-only kit costing around £45,000, rising to £80,000 with labour included. The method is now being honed and developed to create bigger, affordable homes of 750 square feet costing between £85,000 to £120,000 for a finished zero-carbon home, depending on specification and availability of grid services.

The housing minister visited in the summer of 2021 and said the work could make a “fantastic contribution” to the sector.

Sebastian hopes to build eight affordable rental units and four open-market units on an exception site in a local village, complete with solar panels on all the roofs and the highest standards of insulation.

Made largely of engineered timber, non-combustible insulation and clad in standing seam zinc and local chestnut, the two- and three-bedroom homes would be prefabricated within the barn and then taken to the site for fast assembly with the aim of employing local workers.

Sebastian, whose estate comprises woodland, mixed farming and more than 50 commercial and residential let properties, says:

“An essential part of the equation is energy costs, as people need to be able to afford to live there.

They will need little electricity to run, and you will be able to charge your electric car at the same time. We hope the homes will be net carbon positive within 30 years, with a small annual surplus of renewable electricity going to the grid."

“Fuel poverty and cost of living is a real issue as well as affordability both to rent and for the landowner, so it all has to go together as a package.”

Sebastian hoped to lodge a planning application by the end of 2021. Bill, who designed the Beddington Zero Energy Development (BedZED), the first large-scale, environmentally-friendly housing scheme in Hackbridge, London, says he is working with the estate to set up training courses for people interested in buying kits. The aim is for communities to “start to solve their own housing and power problems without a high carbon footprint”, he says.

Sebastian adds: “We must get the environmental performance of housing right, otherwise you’re baking in problems for 100 years.