A few years back I developed (along with Sheri Newbold and Justin Fogle, fellow former Presidents of the Seattle Chapter of the Northwest EcoBuilding Guild) a presentation describing the benefits of allowing increased density in Seattle’s single-family neighborhoods. We called it Walkable, Livable Communities, and we gave our presentation to several community groups, policy makers, and agencies.

In brief, the presentation boiled down to the following:

  • Seattle is destined to grow substantially in the near future;
  • That growth can be sustainable, and occur within the city limits, or it can be unsustainable, and lead to more sprawl;
  • Most of the developable land in Seattle is currently zoned single-family;
  • We proposed that the City allow more variety within single-family neighborhoods, to let a good part of the predicted growth happen there (by “variety” we meant such things as: cottage developments, retail on corner lots, duplexes, triplexes, apartment buildings, mixed housing types adjacent to one another, etc).*

The diagrams below show how the idea of sustainability in regard to cities has evolved over time – in both scenarios, red is bad. The old way of thinking, illustrated on the left, shows CO2 per square mile, more concentrated in the denser urban zones than in the outlying areas (so, cities are BAD).  Cities were considered unpleasant, dirty, polluted, and unsafe. The diagram on the right shows CO2 per household, and from this perspective cities are GOOD.

CO2 per household diagram

The chart below shows the density per square mile of several cities, including Seattle.  Clearly Seattle is less dense than many others, including Los Angeles, which is usually thought of as a sprawling, less dense urban area.

density per square mile of several cities

Density is a loaded word and concept, and has negative connotations for some people. Part of this negativity (sometimes called NIMBYism – as in Not in My Back Yard) might be explained by the prevalence of poorly designed, poorly built condo developments, which people may envision when they hear the term “density”. Because these often happen on the boundary between SF and MF zones, some people think they’re allowed in Single-Family neighborhoods.

Some people fear that increased density will lead to lower property values. This is often expressed as an aversion to rental properties, or the feeling that renters have less incentive to maintain their homes and yards.

Parking, of course, is a controversial issue, with the concern that increased density will lead to more parking congestion and traffic. This is a chicken and egg question – since increasing density and potential public transportation ridership, and encouraging local businesses, will lead to less need for automobiles.

Others fear that higher density will make neighborhoods less safe and secure. As with really all of these concerns, it’s more an issue of good design than density per se.

Our presentation pointed out that the zoning we know today is a relatively new concept. In the past different uses and densities were allowed together, on a block by block basis. Only later did we establish the division of zones that we see today – large swaths of area for one kind of use only. We can still see traces of the old zoning (or lack of zoning) in areas – in existing buildings and development patterns that would not be allowed under current code. Here are some small retail spaces at a corner lot in Capitol Hill currently zoned SF:

corner lot in Capitol Hill currently zoned SF

Cottage housing was built in single family neighborhoods in Seattle to create affordable housing, or housing that met other needs. These are the Pine Street Cottages built in 1916, and renovated in the 90’s.

Pine Street Cottages built in 1916, and renovated in the 90’s

This is an older duplex in Queen Anne:

older duplex in Queen Anne

A triplex in Wallingford:

triplex in Wallingford

And a fourplex on a 4000 s.f. lot in Queen Anne, currently zoned single-family.

fourplex on a 4000 s.f. lot in Queen Anne, currently zoned single-family

The photo below shows two lots in Ballard, each 2500 square feet. This would not be allowed today, in this SF 5000 zone.

two lots in Ballard, each 2500 square feet

The drawings below show a typical corner lot (on the left), and a re-zoned corner lot (on the right), which illustrates the condition in the above photo. We propose that this be allowed again, that existing corner lots can be subdivided. An advantage to this would be allowing the single-family character of the residential neighborhood (pedestrian activity, visual interest, eyes on the street etc.) to wrap around onto the side streets as well. Incidentally Portland allows duplexes outright on corner lots.

re-zoned corner lot

In addition, there are some new ideas that would allow more housing in single-family neighborhoods, and give homeowners more options, in ways that could maintain the scale and character of those communities:

A Flex House adapts over time to respond to its owners’ changing needs. For example, a young couple may move into the upper floor of their Flex House (as illustrated below) and rent out the lower floor. When they start a family and need more room, they take over the whole house. Then, as their kids grow up and move out, and the parents become less mobile, they can move into the lower floor and rent out the top. The nice thing about this idea is that, along with adapting to match the owners’ needs, it would encourage people to stay in their homes longer. The Flex House would require zoning codes to become more resilient, and able to be altered over time for particular lots.

Flex House adapts over time to respond to its owners’ changing needs

Many of the ideas we’ve discussed are not new ones – as shown, almost all were legal inSeattlein the past. These can benefit homeowners, by giving them more options for their property, to accommodate extended family, or bring in extra income. They can accommodate a good part of the projected growth thatSeattlewill experience, and offer many of those new residents a broader variety of housing options.

Zoning terminology has changed over the years – remember “Single-Family” zoning is a relatively new idea. Maybe it’s time to reclassify our in-city residential neighborhoods – not as “Single Family Residential”, but just…”Residential”.

*Incidentally, this presentation initially included Detached Accessory Dwelling Units – the City has since passed the Backyard Cottage Ordinance.