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Change The Rules: Let Tiny Houses & ADUs Flourish

In any community we like to think of safe, affordable housing as something everyone deserves. But today in hot market cities from San Francisco to Boston, housing is out of reach. According to data from The Warren Group, the median single-family home sales price in Newton, just outside Boston, hit $1.1 million in 2016. That’s the median price.

In between the dwindling number of publicly subsidized housing and multi-million dollar penthouses, the vast “missing middle” of affordability just keeps growing.

Housing has a lot to do with supply and demand – and the dynamics of land value – but any analysis must begin with a look at who needs the housing in the first place. Right now and in the foreseeable future, demographic trends suggest something very different from two adults, two kids, and a dog. According to Harvard’s Joint Center for Housing Studies, far and away the biggest growth from 2015 to 2025 is singles and married couples with no kids.

The people needing housing include the schoolteacher or health-care worker, millennials living with their parents, aging baby boomers and empty-nesters looking to right-size, and seniors hoping to age in place. For the most part, they want to live reasonably close to work, in urban areas with ready access to transit. Clearly not everybody wants or needs a 2,500-square-foot single-family house on a half-acre.

That’s the problem. What could be part of the solution? Expand the range of housing options with smaller living spaces – so-called tiny houses, and accessory dwelling units.

We’ve seen design innovation and efficiency a bit more in transportation, whether the mini or electric scooter, but recently designers have been coming up with many similar solutions for housing – like the Katrina Cottage, initially intended to replace FEMA trailers across the Gulf Coast; or the Plug-in House, assembled in six hours with interlocking puzzle pieces, just to name two.

Alongside such new construction is loads of affordable housing – already built – just hiding in plain sight: outbuildings and carriage houses, granny flats, in-law apartments over a garage, basement living spaces, and other accessory dwelling units, or ADUs.

There’s much more, including micro-apartments of 300 square feet or less. Who needs expensive extra living space in the city, when parks and food and We-Work spaces and culture are all right outside the front door? The extreme versions of this approach can be seen in homes made out of shipping crates and Japan’s legendary capsule hotels.

Right-sized living is far from a new idea. The architect Le Corbusier was a pioneer, from his cabanon at the Cote d’Azur to the super-efficient and well-designed density of Unite d’Habitation. This was a good idea then, as it is now.

A half-century later, tiny houses and ADUs are seriously trending. They’re poised to scale up. There are pre-fab tiny houses that can be put on wheels. A Boston teenager made it his summer project to build one from scratch.

But there’s a problem. A big one. The Boston Housing Innovation Lab had James Shen, designer of the Plug-in House, assemble a prototype in front of Boston City Hall in May, suggesting how modest living spaces could be plunked down in a backyard to address the city’s severe affordable housing crisis. But the Plug-in House is totally illegal in Boston right now. You can’t put it in your backyard. There’s a virtual ban on accessory dwelling units. Over the decades, neighbors fretted about congestion and parking. They peer past curtains and report it to City Hall if they see an extra satellite dish. In thousands of communities you can’t have so much as a kitchen sink in an outbuilding unless the people living there are related to you.

These regulations and codes were based on another time. They’re obsolete — just getting in the way now. Like a lot of things, the rules need updating. Happily, many places are doing just that – Durango and Denver in Colorado, Portland and Vancouver; LA is allowing backyard shelters for the homeless, and Washington wants to make ADUs as ubiquitous as bike share.

Boston is taking incremental steps to liberalize those outdated restrictions – and again the driver here is the pressing need for affordable housing. The Housing Lab has published a range of demographic profiles to show how today’s housing needs simply don’t require so much space. The proven formula is a roof overhead, in an urban environment with access to transit, reasonably close to workplaces, and sustainable and energy-efficient.

The City of Newton – home of that million-dollar median home — is hoping to free up thousands of units with better rules allowing tiny houses and ADUs.

It’s important to note this is not a free-for-all. All of these communities are maintaining regulations on maximum occupancy, building safety, parking, and restrictions or even bans on short-term rentals like AirBnB; plus design guidelines for appearance.

This is a classic case of the importance of the underlying rules of the game – the land use regulations, zoning, and building codes that guide our built environment. These more technical matters aren’t nearly as sexy as the shelter porn in Dwell magazine. But you can’t have one without the other.

If we change those rules, we can allow the design innovation to flourish – and disrupt current perceptions about urban living. Tiny houses and ADUs are the electric scooters of housing. Shelter doesn’t require vast amounts of paperwork and permits, old-school construction materials, or land. It doesn’t have to be a big deal. Once we acknowledge that, all kinds of possibilities open up – renovated rooming houses and dormitories, residential over retail, shared-equity housing and community land trusts.


So that’s the call to action: support reform in your community. Let that teacher live in the carriage house out back. Clear the way for homeowners to put a Plug-in House in their backyard. We’ll all be better for it.

This post is written by Anthony Flint; Anthony is a senior fellow at the Lincoln Institute of Land Policy, a think tank in Cambridge, Mass.