When it comes to innovation, self build leads the way

Building your own home has always been a major pipedream for many Britons, proved by the enduring popularity of Grand Designs and similar shows covering renovations, conversions and even mini-homes.

But for the past few decades the proportion of the population actually doing it has stuck doggedly at around 10 per cent. Why? Because it’s been so much easier to do what everyone else has been doing: buy a new, or more likely, an existing house. Those are the properties that fill estate agents’ windows and high street lenders provide mortgages for.

Meanwhile the media have fed, and fuelled, our obsession with rising house prices. Actually building the things has been a minor detail. Note the past tense. Because that minor detail has come back to bite us.

Successive governments have promised more new homes, while ensuring property prices continue to rise. Now they’re well beyond the reach of anyone on an average salary, even if they are able to get a mortgage. Which they aren’t because of the tight lending rules adopted after the 2008 recession. The same rules, incidentally, wiped out most the UK’s small housebuilders, leaving the market to 10 major developers who have no incentive to build any more homes than they can sell at the highest prices.

Even the government is now showing signs of panic. Ex-minister Sir Oliver Letwyn recently called for a cross-government task force to co-ordinate existing initiatives to boost housebuilding. But where is anything actually happening?

It’s happening with self build, and in ways that are increasingly ingenious and imaginative. Perhaps the best known is ‘custom build’ – a term adopted by the government in 2011, partly to sound more user-friendly, but also to preserve the role of the developer.

Here, the developer provides a minimum of a ‘serviced’ plot – one with all utilities and road access. To that can be added obtaining planning permission for your design and construction to agreed stages – from a watertight shell to a finished build.

The UK’s biggest custom-build site is at Graven Hill in Oxfordshire (gravenhill.co.uk) where almost 2,000 homes are planned, including a wide variety of sizes and designs, only limited by a designated palette of local materials.

Other custom-build sites, however, come with basic designs which can be modified for individual requirements. One scheme which recently went for planning in Enfield in north London demonstrates an ingenious compromise between watertight shell and completed project. Developer Naked House (nakedhouse.org) is creating a row of one-bedroom mews houses, each provided with electricity, heating and a basic bathroom. And that’s it.

“It’s complete in a minimalist sense,” explains Naked House co-founder Rachel Bagenal. “It can get a mortgage, it passes Building Regulations and it’s habitable. But beyond that we have left everything that it’s possible to leave for people to do themselves.”

Extensions

In practice, each property can be expanded into an 80-sqm three-bedroom home. The design, by architects OOMX, includes a load-bearing party wall at the rear, making extensions easy to add, and a structural plinth at ceiling height, enabling a mezzanine floor to be added without further reinforcement.

But offering design freedom is only part of the self-build solution. Even more important is making the cost affordable.Naked House is a not-for-profit developer with its sale prices based on average local incomes – in Enfield’s case around £35,000 a year. Their land is obtained from local authorities and public bodies, often small or derelict plots that are uneconomic for a major housebuilder. Rachel Bagenal believes there are around 100,000 sites like this in London.

The land for Naked House’s first development was bought from Enfield Council on a deferred payment basis with funding for construction from social investors, including the Mayor of London.

Meanwhile, architect Alastair Parvin takes a more radical approach to self build. He’s the co-inventor of the WikiHouse, an ‘open source’ – i.e. free – house construction system, which can be downloaded from the internet and customised in SketchUp, a design programme that’s also free.

Files can be produced for a CNC machine – basically a computer-controlled cutting machine – using standard sheet materials, such as plywood. The result is a collection of numbered parts which can be assembled, IKEA-style.

“You need to be able-bodied,” says Alastair Parvin, “but you don’t need to be skilled to build a millimetre-precise, very low-energy home.”

The system, he believes, is actually a return to traditional vernacular housebuilding, which was basically self build.

Whether a WikiHouse will impress your local building control department is another question, but Alastair Parvin has an answer for that, too. He and his team at Open Systems Lab (opensystemslab.io) are developing BuildX, a web-based form of building design, which is a kind of CAD (computer-aided design) plus.

“Imagine,” he says, “being able to go onto a web platform and customise a design in which the rules of building are baked in. As you design, it’s counting every single screw, calculating the energy impact and counting the cost. Straightaway you’re able to spit out a bill of materials, which is everything you need to buy, and an assembly guide.”

BuildX is currently designed to work with WikiHouse, but could be compatible with any digital building system. Parvin believes it could dramatically reduce both the unpredictability and the cost of building houses, stripping out whole levels of bureaucracy on the models of Uber and Airbnb.

Including the vagaries of the planning system? Well, that’s where PlanX, Open Systems Lab’s digital planning platform, comes in. Still at an early stage, it aims to put local planning department’s policies online, enabling designers to see, as they design, exactly what will and won’t be acceptable.

The idea is a beguiling one. But, as Britain’s hard-pressed planning departments aren’t always sure what that is themselves, I suspect that project may take a little longer.

August 2018