Saturday, September 19, 2009

Granny Flats and why you want them

The best definition of an ADU comes from an issue of New Urban News, Dec 2001:

"Granny flats add flexibility and affordability. 
In several new urban communities, accessory dwelling units are strong sellers and offer benefits to both home owners and developers.
Accessory dwelling units (ADUs) appear under many aliases — granny flats, garage apartments, carriage houses, ancillary units — and they almost invariably show up on a checklist of what sets new urban communities apart from conventional subdivisions. They are by no means ubiquitous, but developers from diverse projects report that granny flats have become a popular amenity and an important selling point.
For some home owners, the most attractive aspect of ADUs is the potential for extra income from renting out the unit. Other home owners view the extra space as a flexible addition that can be used as a home office, as lodging for teenage children or elderly family members, or as a guest room with great privacy.
From a developer’s perspective, ADUs provide an extra tier of housing options — affordable units that can attract people from diverse age and income groups. Another benefit is safer and more lively alleys. With more “eyes on the street,” children and adults are more likely to use the alley for play and socialization".

The article goes on to discuss great examples of win-win opportunities where the concept is implemented, and though describing new housing, it establishes the concept. It could be applied to existing stock through smart adaptation. Some companies are starting to build portable structures to be moved into back yards as needed.

This idea however is very controversial. One story jumped out at me, This from Binghamton NY:
Profs use Facebook info to evict BU students
Originally Published 2007-12-07
By Erika Neddenien
Six Binghamton University students face eviction after their neighbors — two BU professors — used Facebook to determine that they were in violation of the West Side’s R-1 zoning law, Binghamton’s Mayor Matt Ryan said.

The R-1 zoning law, which restricts a chunk of Binghamton’s West Side to “factual and functional families,” is typically only enforced when reports are made about a violation. The issue made headlines in 2000 when two dozen students were evicted from their homes.

To try to get a grip on this "problem" The city commissioned "A Report of the Mayor’s Commission on Housing and Home Ownership"
The result was to suggest the creation of an "overlay district" in which "student housing" was encouraged.
BUT: Within their summary the planners identified the following strategy to limit:"Rebuttable presumption / presumptive limit approach: This approach is a somewhat complex concept. What it amounts to is setting a numerical occupancy limit, which can be waived under specified circumstances, based on the number of unrelated tenants who can live together in a dwelling unit. The limit is waived if the landlord (or tenants) can demonstrate that the tenants are the “functional equivalent” of a traditional family—based on criteria set forth in the Zoning Code. (Most municipalities throughout the U.S. employ this functional family equivalent approach, as a result of Constitutional rulings by the U.S. Supreme Court and the highest courts of most states.) The presumptive limit approach is further complicated by the need to decide whether to apply the same presumptive limit to dwelling units in R-1, R-2, and R-3 districts- -and, if not, how to draw principled distinctions. It also creates endless debates about the rationality of applying the same presumptive limit to large versus small houses, and to houses with many versus few bedrooms " Students considered this a ghetto that limited their choices.
The city in an attempt to quell student outrage at what they conceive of as restrictive zoning addressed them with respect citing they were only interested in their safety. Too many persons in a home is a fire hazard.

There you have it. This isn't the first time the issue of non traditional families living together caused a ruckus. "Exclusionary rules" have been challenged around the country with varying degrees of success. The Fair Housing Act is a response to handicapped persons wanting to live together and having been rebuked. Same sex marriage prohibitions run right into this issue of what constitutes a family or the "head of a household".

In 1985 the following abstract appeared:
MARSHA RITZDORF Iowa State University
Copyright 1985 Urban Affairs Association

Although not often included in the literature devoted to exclusionary zoning practices, an examination of the use and abuse of family definitions in American municipal zoning ordinances is important to those who are concerned with the revitalization of American cities and suburbs. Many of the ideas suggested for innovative reuse of existing housing are linked to the family definition. Accessory units in single-family dwellings and shared housing are two examples. This paper briefly examines the history of family definitions in municipal zoning ordinances, reviews the major court decisions concerning their use and discusses the relevance of the continued use of family definitions when current demographic changes are taken into consideration.

Since then the issue keeps bubbling up. New Urbanists, trying to increase density and walkability in their planned communities meet resistance. Whereas the article at the top sites eyes on the street as a positive. The following article in Reason Magazine argues against it:
"Crime-Friendly Neighborhoods
How "New Urbanist" planners sacrifice safety in the name of "openness" and "accessibility"

ADUs marketed with seniors in mind are doing better. ECHO is a program that is gaining traction. In some cases it pays to be old.

Here are other examples of places struggling with the concept. Denver,
Boston, Provo, and here is a great story from Santa Cruz.

For our purposes it is safe to say that those of us looking for creative ways to solve the housing crisis the idea of ADUs makes sense. Were this to be a widely adopted housing pattern, you can imagine a set of dwellings which enhance "family values". Owners could shift the footprint of their homes as their family composition changes without having to uproot. Homes could expand and contract as needs determined. New homeowners offset mortgage costs. If their family grows they move into the ancillary spaces. When family members move on, the now empty nester has space to rent again. This is an idea whose time has come. Be vigilant and attend those dull zoning hearings. Your life depends on it.


  1. many reasons we should buy a granny house to prepare for aged time. I like these kinds of flat except climbing up flats

  2. Granny flat drawings are sensitive to these issues and through a combined 70 years of experience draw on this to make the process as smooth as possible for all involved. Classic Granny Flats prides itself on the keep it simple method by packaging our units to reduce the amount of small decisions you are required to make.