"In cities across the world, fights over housing affordability come
down to a simple question: how much can be built on a single lot? In
Chandigarh, India, officials are debating whether to double that limit, while Sydney, Australia has seen public clashes over proposals for increased housing density.
Back in the United States, lawsuits in Virginia suburbs, protests in San Francisco, and contentious hearings in cities such as Baltimore and Austin
show that zoning has become a central flashpoint in local politics. One
zoning law that has played a role in these disputes either directly or
indirectly is the floor area ratio (FAR).
FAR limits how much total building space can be constructed on a lot, and it applies to both residential and commercial structures depending on the zoning district. It is calculated by
dividing the total building floor area by the total lot area. For
example, a 5,000-square-foot lot with a FAR of 2.0 allows 10,000 square
feet of building space. That could take the form of a single large home,
several smaller units, or some combination. In all cases, total floor
area cannot exceed the FAR limit.
FAR may seem like a technical, math-heavy zoning rule disconnected
from everyday life. In practice, it sets a limit on building size that
strongly influences what housing gets built and who can afford to live
in which neighborhood.
The faulty logic behind the limit
FARs in the US can be traced back to early 20th-century
New York City. The city initially used height limits to prevent
skyscrapers from obstructing air and light to the streets. In the mid-20th century, planners concluded that height restrictions were inadequate and began supplementing them with FAR regulations to control overall building bulk.
For housing, FAR rules effectively acted as a proxy for height limits
by setting a maximum total building volume relative to lot size rather
than a fixed vertical cap. Other cities followed suit by
adopting similar approaches. Decades of development under FAR rules
suggest that the logic behind the limit is flawed. FAR sets a maximum on
total building volume relative to lot size, but it does not control how that space is used.
A building can fully comply with FAR yet still cast long shadows,
crowd neighboring properties, or occupy most of the lot. Two buildings
with the same FAR can look entirely different: one tall and slender,
another short and bulky, covering most of the lot. Because FAR regulates
size instead of form or placement, its impact on sunlight, airflow, and
open space is inconsistent at best.
The other rationales do not fare better, especially that of
“maintaining neighborhood character.” While often invoked to reflect
residents’ preferences about scale and appearance, the concept of
“neighborhood character” largely refers to a subjective sense
of visual appearance or feel, not a clearly defined metric of public
harm. The term is used to express general opposition, as opposed to
something that is easily quantified or tied to a specific land-use concern.
Another justification is infrastructure capacity. By limiting
building volume, planners aim to prevent overloading streets, utilities,
and schools. However, infrastructure demand depends more on the number
of units and occupancy patterns than on floor area alone. A large
single-family home may place fewer demands on infrastructure than a
smaller multi-unit building with the same square footage.
Many cities can address these challenges more directly through market-based alternatives such as user fees,
impact fees, or private investment, which allow growth while ensuring
that those who consume or benefit from infrastructure help cover its
costs without resorting to distortive zoning regulations.
Fewer buildings, pricier homes
Beyond faulty rationales, FARs produce unintended consequences. To quote the Cato Institute,
FARs “restrict the number of developable square feet of residential
space for a given lot size, and thereby limit the density of co-living
buildings.” By capping total buildable volume, FARs force developers to
make trade-offs about how much to build and how to allocate space among
units. This reduces the number of housing units, discourages mid-sized projects, and contributes to higher prices.
Direct studies of FARs are limited because they are usually bundled
with other zoning rules, which makes their independent effects hard to
isolate. Nevertheless, there are some FAR-specific case studies.
Zurich pursued a policy of upzoning, which is a change in zoning
rules that allows more building space on a lot. By increasing the
allowable FAR, Zurich boosted the number of housing units by 9 percent over a decade. A 17 percent increase of allowable FAR in Mumbai, India, resulted in a 58 percent increase in housing supply, as well as a 24 percent decrease in housing prices in affected areas.
Broader research on density limits reinforces these findings. Allowing more building space increases housing supply and takes pressure off of housing prices, while restrictive land-use regulations limit housing construction and drive up housing prices. An estimate from a Cato Institute policy paper attributes about 20 percent of housing growth variation to density regulations, including FARs.
Scrap the cap
FARs act as an invisible barrier to housing. They do not reliably
protect sunlight, air, neighborhood character, or infrastructure
capacity. Meanwhile, FARs constrain how many units can be built and
raise costs for renters and buyers alike. Moreover, the decision about
how much floor space to build and how to distribute it should be
determined by those with the most at stake: the property owners, the
lenders, and the residents.
While some cities might consider partially relaxing FAR limits as a
short-term measure, the most effective solution is full repeal. Repeal
would free developers to respond to demand, allow more housing units to
be built where people want to live, and make housing more affordable
without relying on burdensome regulations like FARs. It is time to stop
letting this flawed formula dictate who can live where."