Seattle Term · Same as DADU
Backyard cottage builder for Seattle.
A backyard cottage is the everyday Seattle term for a DADU. Standalone small home in the backyard of a primary residence. We design, permit, and build them end to end across Seattle and the Eastside.
Written by Aaron Elisha, founder of MNBE Construction & Development. WA license MNBECCD770R9. Updated 2026.
Backyard cottage and DADU mean the same thing.
Seattle homeowners and Eastside agents use both terms interchangeably. DADU is the technical zoning-code term, abbreviation for Detached Accessory Dwelling Unit. Backyard cottage is what the building actually looks like and what most homeowners search for online when they imagine the project.
The building is the same. The Seattle SMC code chapter is the same. The HB 1337 state law applies the same way. The permit timeline, the cost structure, and the construction sequence are identical. We use both terms depending on the conversation. The full DADU service breakdown lives on the dedicated DADU page; this page is for homeowners researching specifically by the everyday term.
Four reasons Seattle homeowners build backyard cottages.
Long-term rental income
Seattle and the Eastside have tight rental markets and rising rents. A 1,000 sq ft cottage in a desirable neighborhood often carries the principal and interest on the primary mortgage.
Multigenerational living with privacy
Aging parents, returning adult children, or live-in caregivers get their own front door, kitchen, and quiet. Detached buys flexibility that attached and basement units cannot match.
Future flexibility
Build it now, rent for a decade, then move into the cottage and rent the main house when the kids leave. Two legal homes on one lot is a fundamentally different asset than one.
Aging in place
Single-level cottage with a curbless shower and accessible kitchen lets you stay on your property for decades while renting the main house for income.
For the full service breakdown, see the DADU service page. Same building, more depth.
Where to Go Next
The pages that go deeper on backyard cottage decisions.
Full Service
DADU Service Page
The full service breakdown for backyard cottages: process, anatomy, cost factors, timeline, founder note.
See DADU service →
The Law
HB 1337 Explained
The 2023 law that determines what your lot allows for any ADU.
Read the guide →
Step One
Feasibility Studies
Confirm your lot supports a backyard cottage before you commit to design.
See feasibility →Frequently Asked
Backyard cottage questions Seattle homeowners ask.
Six practical answers from a builder who builds backyard cottages every year. If yours is not here, call us.
Still have questions?
We answer the phone Monday through Saturday. Two minutes on the call usually gets you further than an hour online.
A backyard cottage is the colloquial Seattle term for a Detached Accessory Dwelling Unit, or DADU. It refers to a small standalone home built in the backyard of a primary residence on the same lot. Same legal classification as DADU under Washington state law and Seattle SMC. The term comes from how the structure looks (a small cottage in the backyard) rather than from any code distinction.
Yes, in Seattle and across the Eastside. Backyard cottage is the everyday term. DADU is the technical/legal term used in zoning code, permits, and architectural drawings. The structure, the rules, the permitting process, and the build are identical. Some homeowners search and ask about backyard cottages, others about DADUs. Same building.
Up to 1,000 sq ft of gross floor area under Seattle's current code, with a 1,200 sq ft bonus floor available on qualifying lots. Maximum height is typically 18 to 22 feet depending on the zone. Two-story configurations are allowed in most zones, which is how a 1,000 sq ft footprint becomes a comfortable two-bedroom unit. Bellevue, Kirkland, Redmond, and most Eastside cities allow the same maximums.
6 to 10 months from signed contract to certificate of occupancy for a typical Seattle backyard cottage. The breakdown is roughly 3 to 5 weeks of design, 2 to 4 months of plan-check at Seattle DCI, and 3 to 5 months of construction. Aaron's crews build faster than the regional average. We hold the schedule we put in writing.
Yes. Both short-term and long-term rentals are allowed in Seattle and most Eastside cities, with city-specific rules. Seattle requires short-term rental operators to register and limits non-primary-residence STRs. Long-term rentals of 30 days or more are generally unrestricted across the region. We walk through the specific rules for your city during the consultation so the income model you want lines up with what your jurisdiction permits.
Because it describes what the building actually is: a small standalone cottage in the backyard. DADU is bureaucratic shorthand. Backyard cottage is human language. Either way, the building is the same. We use both terms depending on whether we are talking with a homeowner over coffee or filing paperwork at SDCI.
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