Modular housing could provide millions of good new homes. So why isn't it everywhere?

Jenny Stephens/RSHP

Modular homes are built off-site, enabling quick and fuss-free construction. Are they the answer to Britain’s housing needs? 

At the end of the Second World War, the UK faced a severe housing shortage. As troops made their way home, the government was desperate for a quick fix to the 200,000 shortfall of homes. Prefabricated – “prefab” – housing was used to plug that hole: structures built off-site which could be quickly assembled, with a planned life span of ten years. Encapsulated by the more than 100,000 bungalows that were assembled by German and Italian prisoners of war in the 1940s, the style has since developed a bad reputation as low-quality and visually displeasing, but it was vital in Britain’s housing trajectory.

Fast-forward 70 years, and once again the country finds itself in the midst of a serious housing crisis. On average, house prices in England are seven times people’s incomes, and over a million families with children now rent from private landlords. Could modular housing be part of the solution? Maybe, but don’t call it prefab. “Don’t get me started,” retorts Lucian Smithers, director at modular residential developer Pocket Living. “It’s such a lazy association.”

Modular homes are constructed from “modules” that are pre-built off-site in factories. However, Nicky Gavron, former deputy mayor of London and long-time advocate for modular housing, says the recent models are “light years” away from prefab homes of the past. “Now they are precision-engineered, digitally designed, eco-efficient, slashing energy bills and affordable. Not just affordable to build, but to live in.”

“Building prefab bungalows and 27-storey towers,” Smithers continues, “the associations in terms of the technology, are poles apart.” He is referring to Pocket Living’s Mapleton Crescent development in Wandsworth – the tallest residential modular tower in Europe. Both from the outside and inside, it’s hard to tell the development apart from any other tower block in the area. Watching a time-lapse video of its erection, on the other hand, is a unique spectacle. The lift and stair core was built first with slip form concrete – “you just pour in the concrete, move it up, move it up, move it up” – upon which a crane was installed to lift the modules into place. “We were doing a floor a day.That’s five pocket flats a day.”

Modular technology is quick to assemble, which is why historically it has been used in the military and public sector. This is exactly why the country needs it, Gavron argues. “The last time we were anywhere near reaching high housing targets was in the late 60s and early 70s, when factory-built homes played their part … some estimates put completion rates at 60 per cent quicker than traditional construction.” She argues that with such need, the traditional model of housebuilding can “only take us so far”.

As well as being quick to assemble, it is quick, and more sustainable, to disassemble. PLACE / Ladywell, a joint project with Lewisham Council, consists of 24 family modular homes on the site of the former Ladywell Leisure Centre, a site that was vacant and awaiting permanent development. The homes respond to housing need in the borough, but will be de-assembled after four years to be relocated somewhere else. The development is providing a “permanent solution in a temporary location”, according to architect Andrew Partridge, of Rogers Stirk Harbour + Partners.

Another key benefit of modular homes is the ability to use small plots of land that aren’t easily accessible; the homes aren’t built from scratch, reducing the size of the building sites and the number of lorries, mixers and other paraphernalia. “They can now be built at all sorts of densities and for all sorts of sizes of sites, and are appropriate for urban areas as they work over constrained sites, such as those over tunnels, utility infrastructure and by railway lines,” explains Gavron.

“The business model is particularly suitable for the build-to-rent or social rented homes sectors,” she argues. Pocket Living is specifically targeting first-time buyers at the bottom of the affordability scale. “Everyone has to go through a lottery when they go through the purchase process, but you get more tickets if you are single, working in the public sector and you are on the affordability threshold,” explains Smithers. The flats in the company’s Sail Street development were all sold at a minimum of 20 per cent below the market rate, and the cheapest were 40 per cent below it, at £267,000 for a one-bed. “It is for a certain target audience at a certain life stage … we are helping people who are earning in the upper 30s and lower 40s … People [who] have got a degree and a good job, but they don’t have any capital behind them, their parents don’t have loads of equity.”

The combination of modular and affordable housing has caught the attention of the Greater London Authority, who provided Pocket with a £21.7m seed fund in 2013 under then mayor Boris Johnson, followed by £25m more under Sadiq Khan. The developer used it to invest in land; “before that money came in, we were reliant on our own equity, meaning we had to sell a scheme to buy another plot of land. You can only do one scheme every couple of years.” Now the company is building over 200 homes a year. Meanwhile, Lewisham Council and Rogers Stirk Harbour + Partners have three more modular homes projects in the pipeline, one of which has already received planning permission.

It’s clear why this type of construction would appeal to politicians; it’s supposedly as good as a regular build – “to get mortgages, [builds] have to be insurable to the same standards as conventional builds,” points out Smithers – and it’s quick. “They want to see housing, they want to see it fast, and good-quality.”

Gavron thinks yet more political will is needed. “[Modular housing] will only be used more widely if we can crack the issue of scale” she explains. “The industry told me that they are poised for a step- change in delivery. That change is dependent on strong political leadership from all spheres of government acting collaboratively to co-ordinate policy and resources, and provide continuity of demand.”

That most of the building work takes place in factories is also attractive, argues Smithers. “You’re using this pressure cooker of property prices in the South East to fund jobs in the Midlands and the North so I think politically that has a lot of appeal.” He also believes that a factory, compared to a construction site – “a confusing and harsh environment” – is more likely to attract workers and apprentices. Gavron agrees: “This is a new industrial sector where design meets manufacturing opening up a whole range of new job opportunities with the potential to attract new recruits.”

So why aren’t all developers jumping on board? “The large-scale developers are not cut out for this,” says Smithers. “They have worked on their supply chain carefully, and they have negotiated their subcontractors down so efficiently. Why would they take the risk?” They’ll dip their toe in the water “for the PR”, he says, but the business model is so different that they are not willing to take the leap.

The financial services company Legal and General, however, has invested £55m in a modular factory near Leeds, planning to deliver 3,500 modular homes a year. Smithers is suspicious of trying to produce “lots of little [modular] semis”, arguing that high-density builds are the most efficient and economical way of using this technology.

Returning to the prefab label, Gavron says there is “some nervousness, particularly from local politicians who are still involved in pulling down the systems-built housing of the past, whereas today’s models of factory-built homes are quality controlled, low-carbon, digitally designed and precision engineered.” Partridge says although the prefab characterisation is “slightly misguided,” he “doesn’t mind it really”. “We always say you wouldn’t buy a car that’s made in a field, so why would you do that for a house?” His argument is that building homes in a controlled environment means “you can guarantee quality and deliver it.” “We need more demonstrations and expos to show how far they have come,” says Gavron. “These are truly 21st-century homes.”

Jenny Stephens/RSHP
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