The glories of granny flats

In-laws, Outlaws, and Granny Flats: Your Guide for Turning One House into Two Homes. A book by Michael Litchfield. Taunton Press, 2011, 224 pp., $24.95 paperback

As I write this, the ebullient family across the street from me — a mid-thirtyish husband and wife with four bouncy small children — is preparing to move into the home of the children’s grandparents, two blocks away. The grandparents are not exactly departing; they’re constructing an addition on the back of the big, century-old house that they’ve lived in for decades.

When the addition is complete, all three generations will live — happily, they hope — in two connected units on a deep single lot. The young family will occupy the tall house facing the street, and the older folks (who don’t seem old at all) will live in the lower, shingled addition at the rear.

Auxiliary units, promoted for years by new urbanists and by planning consultants such as Patrick Hare, seem to be catching on — whether in old cities, established suburbs, or brand-new developments. In-laws, Outlaws, and Granny Flats is an excellent guide to the changes that are afoot.

Housing analyst Arthur C. Nelson recently pointed out that the number of persons in the average American household rose from 2.59 in 2005 to 2.63 to 2010. In this book, author Michael Litchfield reports that in 1990, less than 15 percent of elderly Americans lived with their children. By 2000, he says, “the percentage of multigenerational households increased — for the first time in more than a century — and by 2008 that number was up 12 percent from its low point.”

Observes Litchfield:

The shift reflected not only elders moving in with their kids, but also young adults who perhaps had never left home: more than a third of Americans 18 to 34 now live with their parents. This shift was partly economic, partly cultural (Asian and Latin American newcomers have far stronger kinship bonds), and partly spiritual. For many people, the Age of McMansions was an empty time. So perhaps our new interest in shared housing is also a search for something more satisfying, soulful, and sustainable.

The change, says Litchfield, can benefit communities:

Open land is preserved. When more people use municipal services, a city’s per-resident costs go down, and city revenues are augmented by property taxes on new units. Because in-law units are typically small, their rents are often modest, too, increasing the pool of affordable housing for seniors, students, and service providers such as teachers, nurses, and elder-care workers. When located in older neighborhoods, in-law units are frequently within walking distance of downtown services. Moreover, because private owners create that affordable housing, cities needn’t tap their limited resources to do so.

And because they are built on existing parcels and often built within an existing footprint, in-law units are among the greenest ways to build. They’re smaller and so require fewer resources to build, operate, and maintain.

Litchfield, who lives in Point Reyes, California, and who has been renovating houses or writing about them for more than 30 years, doesn’t provide a tally of the number of communities that have changed their laws to allow secondary units. The law always evolves more slowly than people’s lives, so I’m certain there are plenty of the “outlaws” referred to in the book’s title — dwellings that evade zoning laws or building regulations.

At the municipal level, Litchfield praises the success of the Accessory Dwelling Unit Development Program of Santa Cruz, California, which streamlined the permit and approval process, reduced fees, produced manuals that walked homeowners through the development process, and created a set of seven prototype plan sets, which, if followed, result in an automatically approved in-law unit. In a high-cost locale like Santa Cruz, accessory dwellings help to provide much-needed housing.

Helpfully, Litchfield presents a one-page table on common zoning standards shown here on the right. Drawn from municipal codes around the country, it summarizes the more common zoning standards governing accessory or auxiliary units (popularly referred to as granny flats or in-law units). A typical specification may restrict the accessory unit to no more than 750 square feet, allow the combined house and accessory unit to cover no more than 30 to 40 percent of the lot, and require that the lot be at least 5,000 square feet.

The standards often say that both units’ entries cannot face the street, unless the smaller unit’s door is screened from view — though this varies from one municipality to another. This sometimes makes it difficult to create an appropriate entrance for an attic or basement conversion. Owner-occupancy is generally required; the property owner must live in either the house or the in-law unit. Consequently, the owner has a strong stake in finding responsible tenants and keeping the property in good condition.

The code often requires additional parking space and forbids the owner from reducing the number of parking spaces, Litchfield says. Generally, there must be at least two parking spaces for the house and one additional space for the in-law unit.

Besides rental income, an auxiliary unit may generate other financial benefits. “It’s perfectly legal to combine federal tax credits, state credits, and local utility rebates for energy-saving work done on your home or in-law unit,” he reports. “In fact, many agencies encourage homeowners to piggyback such incentives.” In some areas, low-interest accessory dwelling unit loans are available from programs managed jointly by a city agency and, for instance, a local credit union.

The bulk of the book tells how to go about planning and building an accessory unit — over a garage, in an attic, in a basement, in other parts of a house, or as a bump-out, or in some other form. Litchfield presents a generous assortment of color photos, plans, drawings, and other images. He offers detailed advice on many of the challenges an owner is likely to face.

Examples of projects around the nation reveal how people have created accessory units in differing conditions and in all sorts of styles. Litchfield urges homeowners not to create an in-law unit without a building permit. If you’re caught, there may be fines on top of the permitting fees.

This is an eminently practical as well as handsome book. It comes at a time when the demand for this kind of knowledge is destined to grow.