Guide · Covington · King County · Updated July 2026
How many units can you build in Covington?
If you own or are evaluating a residential lot in Covington, the first question is almost always the same: how many homes can legally go on it? Since Washington's HB 1110 middle-housing law took effect, the answer for most Covington lots is now more than one. Covington guarantees at least 2 units per lot on any residential lot, with total capacity set by the zone's base density (e.g. R-6 = 6 homes/acre) rather than a flat per-lot cap.
Covington at a glance: at least 2 units per lot, with more allowed by lot size and zoned density, plus up to 2 ADUs under HB 1337. Source: CMC 18.30.030 & 18.15 (Ord. 04-2025).
What Covington's adopted code allows
Covington guarantees at least 2 units per lot on any residential lot, with total capacity set by the zone's base density (e.g. R-6 = 6 homes/acre) rather than a flat per-lot cap.
The details: no separate transit tier (Tier 3) — total capacity is set by the zone's base density (for example R-6 allows 6 homes per acre). These are Covington's city-wide standards, per CMC 18.30.030 & 18.15 (Ord. 04-2025); the exact figure for a specific parcel — its zone, lot size, transit proximity, and critical areas — is what a Civexa report resolves.
What actually fits: floor area, height, and setbacks
HB 1110 and the city code set the right to a number of units; the zone's building envelope sets what physically fits. Floor-area ratio, lot coverage, height, and setbacks together decide whether those homes pencil as detached cottages, a townhouse row, or a stacked-flat building. Civexa computes this envelope for Covington zone by zone, so the unit count you see is one the zoning can actually hold.
What can shrink it: critical areas
Steep slopes, wetlands, streams, and flood zones can override the unit math on a specific parcel. A lot that qualifies for the maximum on paper may be constrained once environmentally critical areas are mapped. Civexa screens FEMA flood, slope, and county critical-area layers for every Covington address so you find this out before you make an offer, not after.
Get the exact number for your Covington parcel
The figures above are Covington's city-wide rules. The number that matters is the one for your address — its zone, lot size, transit proximity, and critical areas. Civexa turns that into a full feasibility report in about a minute: unit count, buildable envelope, a preliminary pro forma, utilities, and permit path.
Run a Covington feasibility report →
Frequently asked
How many units can I build on a residential lot in Covington?
Covington guarantees at least 2 units per lot on any residential lot, with total capacity set by the zone's base density (e.g. R-6 = 6 homes/acre) rather than a flat per-lot cap. That is per CMC 18.30.030 & 18.15 (Ord. 04-2025). The exact number for a specific parcel still depends on its zone, lot size, transit proximity, and critical areas — run a Civexa report for the parcel-level figure.
Can I add ADUs on top of that in Covington?
Washington's HB 1337 allows up to two accessory dwelling units on a residential lot. In some cities they count toward the middle-housing total and in others they are separate — your Civexa report applies Covington's specific rule.
What unlocks the maximum in Covington?
No separate transit tier (Tier 3) — total capacity is set by the zone's base density (for example R-6 allows 6 homes per acre).