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Author Michael Litchfield on Turning One House Into Two: In-Laws, Outlaws and Granny Flats

A new book documents the ways American families are re-arranging themselves in light of deep-seated economic and demographic trends

By Nalina Moses

Over the past decade, financial uncertainty, high housing costs, an increasing elderly population, and a rising number of multi-generational households have led more and more homeowners to add secondary living spaces to their homes. Referred to as ADUs (additional dwelling units), these units can serve as housing for aging parents, adult children, guests, or renters, and are changing the definition and purpose of “roommate” in polite middleclass society.

A new book by Michael Litchfield, In-Laws, Outlaws, and Granny Flats: Your Guide to Turning One House Into Two Homes, (The Taunton Press) documents this trend, highlighting some particularly inventive ADUs and looking at the challenges in planning and constructing these secondary units. Litchfield is well-qualified to comment: He's a journalist and home builder who's worked over thirty years in the residential construction industry, and a founding editor of Fine Homebuilding magazine. Though he’s not an architect, Litchfield’s position has given him a fresh (and sometimes unexpected) perspective on the role architects can play on home remodeling projects, from design, to shepherding projects through the public approvals process, to communicating the design intent to skeptical community members. As a home builder that values the contributions architects make to residential projects, Litchfield can advocate for their expertise in ways architects themselves can’t. AIArchitect caught up with him over e-mail to ask how the growth in ADUs is impacting residential architecture.

AIArchitect: There are so many colorful vernacular expressions for ADUs, like "sidekicks," “carriage houses," "guest cottages," "bachelor apartments," and even, in Australia, "kangaroo units." Besides "ADU," can you think of a term that describes them well?

Litchfield: “Secondary living spaces” is a bit more neutral, but my favorite is simply “in-laws,” and it’s the term I hear most often. I also like “in-laws” because it connotes family and connectedness, which are very positive.

This increase in ADUs seems linked to the current cloudy financial climate. Do you think the trend will reverse itself as the economy becomes more stable?

That’s unlikely, because the economy is only one of several contributing factors.

Perhaps the single most important trend spurring ADU growth is our aging population, especially the huge crop of Baby Boomers who are in the thick of caring for elderly parents while planning for their own retirement. ADUs can help them do both. Compounding those responsibilities is the staggering cost of assisted living, which continues to soar in good times and bad. Home and community based care are about one-third the cost of a nursing facility, according to an AARP 2010 survey of long-term care and independent living. The percentage of multi generational households has also increased dramatically, up 40 percent since 1990, in part because new arrivals from Asia and Latin America favor extended families. Interestingly, this reversal of a century-long decline in multi generational households may actually be a return to a traditional American family structure. Lastly, green building, smart growth and urban infill are here to stay, and there are few ways as green and smart as creating second units. They also make better use of underutilized properties and municipal infrastructures.


The increasing number of ADUs has great synergy with smart growth planning and green initiatives, as it leverages developed properties and infrastructure. Yet many towns limit their construction. What are some of the apprehensions?

Mostly it’s fear of the unknown, which can best be dispelled by knowledge. Architects can play an important role here. A savvy architect I know throws a party for the neighbors whenever a client wants to create an ADU. She’ll create a color rendering or a model of the in-law unit, get some wine and cheese from Costco, and hang around to answer questions. As she puts it, “People are less likely to be grouchy at a party, and it defuses their doubts because it’s all in the open.”


Is the planning, permitting and construction process for an ADU is more complicated than the process for a new single-family home? What can an architect do to expedite the process?

Getting ADUs permitted and built isn’t inherently more complex or difficult. It all hinges on whether a municipality is gung-ho or cool towards them. Whatever the prevailing attitudes about second units, however, architects can play an essential role in assisting clients who want to create one.

First, a seasoned architect will be conversant with local planning issues in a way that a generalist homeowner will never be. An architect will know, for example, which zoning issues will trigger a public review of a project or otherwise impede approval. Also important, architects know how to complete the baffling assortment of documents that many cities require. And they can talk the talk. As a builder in the book put it: “Your documents must not only explain clearly what you want to do, but explain it in the way that planners want to hear it.”

A competent architect will create a design that, while satisfying client needs, will comply with zoning requirements—or make a credible case for varying them. Modifying a design to reach a compromise with zoning authorities is another essential skill. Lastly, an architect can represent clients’ interests and advance their ADU project in a dispassionate, professional manner. Getting neighborhood buy-in or planning commission approval takes experience and tact, qualities often overlooked by clients who think they can do it themselves and save money. When a project is in any way uncommon or contentious, an experienced architect is a great ally to have.

For people living in large, densely populated cities, there often aren't the same opportunities to build detached ADUs. Are there other strategies in urban areas that are being employed?

If you are talking about a city as dense as Manhattan, certainly your options will be reduced. It would be almost impossible to create, say, a backyard cottage. But ADU configurations such as attic, basement, and garage conversions fit entirely within an existing footprint, and so minimally impact a lot, except [that] they require entrances, stairs, access or parking spaces. In the book, there’s an ADU type we’re calling a “carve-out,” which is particularly well-suited to urban residences with under-utilized space. Basically, carve-out ADUs appropriate a suite of rooms with a bath, typically adding a kitchenette, soundproofing, and closing off or creating doorways as needed.

Robert Frost famously observed that good fences made good neighbors. Can we say that in-law apartments, by providing both closeness and separation, make stronger families?

Well, I wouldn’t try to top Old Bob, so I’ll meet your quote with a scoop for AIArchitect and a poem of my own. The scoop is that Frost, when not writing poetry or teaching, dabbled in real estate. He bought up farmhouses in Vermont and New Hampshire, at one point owning 30 or 40, including a sweet little cape in Concord Corner, Vt., where I lived in the early 1970s. So, in counterpoise to that frosty tale, this sunny rhyme:

In-laws, outlaws, granny flats,

You’ll prosper with two welcome mats.


Image courtesy of The Taunton Press.


A backyard cottage in Eugene, Ore., by Fifield Architecture + Urban Design. Photo by


A detached grandparent house by Frederick Hyer and Patricia Fontana-Narell. Photo by Muffy Kibbey.


A house with an attached rental unit in Seattle, designed by VELOCIPEDE Architects. Photo by Muffy Kibbey.


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