Zoning Bonuses: MORE READING

Seattle is on the cusp of a “missing middle” housing transformation. In late 2025, the City Council approved a series of amendments to the Comprehensive Plan and zoning code that incentivize building “stacked flats” – essentially low-rise apartment or condo buildings – in formerly single-family zones[1]. These zones, now officially called Neighborhood Residential (NR) zones, make up about 75% of Seattle’s residential land. The new policy represents a fundamental shift in what can be built in these neighborhoods. Where once only one house (and maybe a couple of accessory units) stood, developers may soon build up to a 12-unit multiplex on a standard lot by layering multiple bonuses. This article breaks down the key zoning changes enabling stacked flats and why they are a potential game changer for housing in Seattle.

From Single-Family to Neighborhood Residential

Seattle’s Neighborhood Residential zones replaced traditional single-family zoning in name, but until now their development capacity remained very limited. Mayor Bruce Harrell’s initial proposal for the Seattle Plan envisioned at most three-story stacked flats on large lots near transit, and even that was considered unlikely by many builders[3]. Housing advocates warned that without significant incentives, developers would favor the familiar path of townhouse construction over stacked flats. In response, the City Council adopted a cluster of incentives designed specifically to make stacked flats feasible and attractive. Councilmember Sara Nelson’s Amendment 91 exemplifies this approach – it boosts allowable density by ~50% if a project meets certain green landscaping or tree retention criteria. Likewise, other amendments raised height limits, floor area, and relaxed parking mandates, all with the goal of unleashing a new housing type in these neighborhoods.

Under the updated plan, Seattle’s NR zoning will actually rival or exceed the capacity of Lowrise multifamily zones. When bonuses are combined, the NR development standards allow buildings approaching the scale of LR2 zoning in terms of floor area and units. In other words, multiplexes of 6 to 12 units could become common on typical lot sizes, whereas previously only 4 townhomes would fit under state minimum standards. This is a significant step toward providing the “missing middle” housing – more affordable, family-sized homes in between single houses and large apartment complexes.

Key Zoning Bonuses and Incentives

Seattle’s stacked-flat initiative isn’t a single zoning change but a package of interlocking bonuses. Here are the major incentives now on the table, which developers can “stack” to maximize a project’s yield:

• Higher Floor Area Ratio (FAR): The base FAR limit in NR zones was lifted from 1.2 to 1.6 (a 33% increase), with further bonuses up to FAR 2.0 possible for projects that meet certain conditions. In practical terms, on a standard 5,000 sq ft lot, FAR 2.0 means up to 10,000 sq ft of buildable floor area (before additional exemptions). This provides room for many more units than the old rules – for example, one analysis found a 5,000 sq ft lot could fit ten ~910 sq ft flats plus some extra accessible units under the new rules.

• Greater Height Allowance: A one-story height bonus is granted for projects that preserve or plant large trees (details in the Green Factor section below). This pushes the height limit up to 42 feet (four stories) in qualifying cases. A four-story walk-up building can accommodate significantly more homes; for instance, stacking four levels of flats (with no elevator required at that height) might yield 12 units on one lot. Previously, NR zoning generally topped out at 3 stories, limiting unit counts.

• Higher Unit Density: The base density was raised to 1 dwelling per 500 sq ft of lot area, which equates to 10 units on a typical 5,000 sq ft parcel. But importantly, certain units are exempt from density calculations now (such as accessible “Type A” units – see below). That means developers can add additional units beyond the density cap if they fall into those exempt categories. By combining exemptions, it becomes feasible to reach 12 or more units on one lot without a formal upzone.

• Lot Coverage Bonus: Normally, buildings in these zones can only cover 50% of the lot, but with the stacked flat bonus this limit increases to 60%. More lot coverage means a bigger building footprint, which helps achieve the higher unit counts and floor areas now allowed. This bonus pairs with the height increase: a slightly larger footprint and an extra story together yield a substantially larger building envelope.

• Parking Requirement Reduction: In line with a new state law, Seattle eliminated parking minimums for most small housing developments (discussed in detail in the Parking Reform article). The short version: no off-street parking is required for units under 1,200 sq ft or for projects in designated transit-rich areas. Even outside those areas, the requirement is just 1 stall per 2 units, which is far less onerous than one per unit. This reduction is crucial – many NR lots can’t accommodate parking without expensive garages or surface lots that eat space. By removing the parking hurdle, more of the lot and budget can go toward housing.

• Accessible Unit Exemptions: Any fully accessible Type A units included in the project are excluded from FAR, lot coverage, and density calculations. In effect, the city is rewarding developers for building accessible housing by not counting those units against the limits. For example, adding two Type A units on the ground floor lets you exceed the standard unit count and floor area for the site.

Each of these bonuses individually nudges projects toward greater density; together, they fundamentally change what’s possible. As one industry expert noted, this cluster of incentives collectively makes stacked flats “one of the most viable missing-middle plays in Seattle” by ensuring the numbers pencil out. The city wants more of this housing and has aligned the code to encourage it, from higher FAR and fewer parking stalls to even promises of a smoother review process for compliant projects.

What This Means for Neighborhood Development

The new zoning regime sets the stage for a potential multiplex boom in Seattle’s neighborhoods. Instead of predominantly seeing townhouse complexes (the four-pack or six-pack townhomes that have proliferated in recent years), we could see more small apartment buildings with single-level units. This diversification in housing types can fill a crucial gap: larger units suitable for families or downsizing seniors, but in a smaller-scale building embedded in a residential street. These buildings are expected to remain a minority (one estimate is maybe 5% of projects might opt for stacked flats over townhouses). Nonetheless, even a modest uptake could create hundreds of new homes that otherwise wouldn’t be built under stricter zoning.

For developers and homeowners considering projects, the key takeaway is that there are now many more avenues to add housing on an NR lot. By smartly leveraging incentives – retaining a big tree here, adding an accessible unit there – one can maximize a site’s yield. Of course, doing so requires threading the needle with thoughtful design and planning. In the articles that follow, we dive deeper into each major incentive (from Green Factor landscaping to parking reforms) and other critical factors beyond zoning rules. Understanding these details will be essential for anyone looking to capitalize on Seattle’s new middle-housing-friendly policies.