Alan Durning from Seattle’s Sightline Institute has put together a 50 page eBook polemic called Unlocking Home that explores and advocates for three simple code changes many North American cities could make, to almost instantly create hundreds of thousands if not millions of affordable residential units in our existing cities, without requiring subsidies or even much construction. They all center around bringing back historical dwelling forms that have provided intrinsically affordable housing for as long as people have lived in cities, and eschewing our current habit of legally mandating middle-class norms of desirability for everyone, regardless of their own personal taste or economic means.
First, he advocates re-legalizing rooming/boarding houses in which private sleeping/living areas share some common spaces and amenities (bathrooms, kitchens, courtyards, laundry facilities, gardens, etc.). This type of living arrangement provided affordable housing for not just the poor, but working class singles and the young and upwardly mobile in North American cities for a century or more, before it was shut down for largely racist reasons in the 1920s, with the advent of “modern” zoning laws.
Second, (in a chapter which is posted in full on Shareable) he says we should decriminalize roommates — in Cascadia alone he estimates that there are roughly 5 million bedrooms in which nobody is sleeping, partly because of occupancy limits which prohibit non-family members living together. Even if only a small fraction of those rooms got rented out, it would be a vast affordable housing resource. Boulder has exactly the same kind of laws, and they make creating a (legal) housing co-op here nearly impossible.
Third, he points out the latent sub-lot-scale infill capacity that converted garages, basements, carriage houses, garden cottages, and other Accessory/Auxiliary Dwelling Units (ADUs) represent. Vancouver’s Kitsilano neighborhood — a low-rise area filled with 2 and 3 bedroom duplexes built in the 1920s — managed to illegally double its population density via ADUs by the 1980s, to about 13 dwelling units per acre, without altering the character of the neighborhood. This density is enough to allow neighborhood retail and self-supporting full and frequent mass transit. After the fact, Vancouver decided to decriminalize these accommodations, regularizing and then encouraging them — currently they’re debating whether to require new construction to be built such that conversion to ADUs is cheap and easy in the future.
These three code changes (along with the end of off-street parking requirements) are really the low hanging fruit of sustainable, affordable housing development. Fixing these codes is just getting out of the way, allowing people to live modestly if they prefer to do so. There are also much more aggressive and exciting ways forward, like the Baugruppen of Germany — collaborative, community-oriented owner-built urban infill developments that now house hundreds of thousands of people.