DADU rental income in Seattle: the real numbers
A backyard cottage is one of the few investments you can literally build in your own yard. But "build it and the rent will come" skips the part that decides whether it's smart for you: what it actually earns, how you finance it, and how it changes your property's value. Here's the math, without the hype.
What a Seattle DADU actually rents for
As a long-term, unfurnished rental, most Seattle DADUs bring in roughly $1,800–$2,800 per month. Where you land in that band is driven by three things: size, neighborhood, and finish quality.
| Unit type | Typical monthly rent | Best for |
|---|---|---|
| Studio / small 1-bed (≤500 sq ft) | $1,500 – $1,900 | Singles, students, downsizers |
| 1-bed (500–650 sq ft) | $1,800 – $2,300 | Couples, remote workers |
| 2-bed (700–1,000 sq ft) | $2,300 – $2,800+ | Small families, roommates |
Rents in USD; ranges reflect typical long-term unfurnished lease comps and vary by neighborhood. Furnished mid-term rentals can earn more but carry more vacancy and management.
A furnished mid-term rental — a 30-to-90-day stay for a traveling nurse, relocating professional or insurance-displaced family — can lift gross rent 30–50%. The trade-off is higher turnover, furnishing cost, utilities included, and active management. For a hands-off owner, a steady long-term tenant usually wins on net.
How owners finance a DADU
Few people write a $300,000 check. The common routes:
- 🏦
HELOC or cash-out refinance
If you have substantial equity, borrowing against your existing home is often the cheapest capital — and the simplest to close. In a higher-rate environment, a HELOC you can pay down quickly may beat a full refinance of a low-rate first mortgage.
- 📐
Renovation / after-value loan
Renovation loan products lend against the home's value after the DADU is complete, which can unlock more than your current equity allows. Useful when you don't yet have enough equity to cover the full build.
- 🔨
Dedicated ADU / construction loan
A construction loan funds the build in draws and converts to permanent financing. Some lenders will count a portion of projected DADU rent toward your qualifying income — ask early, because it affects how much you can borrow.
Whichever path you choose, get the financing conversation going before design, not after. The loan structure can change your budget ceiling, and some lenders need the permit-ready plans to appraise after-value.
The cash-flow picture
Here's a simplified, honest model for a mid-range 1-bedroom DADU. Your numbers will differ — this is to show the shape of it, not a promise:
| Line | Monthly | Annual |
|---|---|---|
| Gross rent | $2,100 | $25,200 |
| Less vacancy & maintenance (~12%) | −$252 | −$3,024 |
| Less added insurance & taxes (est.) | −$250 | −$3,000 |
| Net operating income | ~$1,598 | ~$19,176 |
Illustrative only, in USD. Excludes financing payments, which depend on your loan. Not financial advice.
On rent alone, simple payback against a ~$300,000 build often runs 10–18 years. But that view is incomplete on purpose — it ignores the two biggest sources of return.
The value-add nobody puts in the spreadsheet
A permitted, legal DADU does two things at once. First, it adds finished, rentable square footage that lifts your property's appraised value. Second, it adds a durable income stream that makes the whole property more valuable to a future buyer or refinance appraisal. So the real return is the rent plus the equity lift plus ongoing appreciation on a now-larger asset. When you fold those in, a well-built DADU's effective return is usually far better than the rent-only payback suggests — and you've added flexible space you can later use for family, aging parents, or a home office.
Run your own numbers first
The only honest payback figure is a lot-specific one. Your build cost (see our Seattle ADU & DADU cost guide), your financing rate, your achievable rent and your hold period all move the answer. We model all four during a feasibility study on our ADU & DADU service — so you see the real return before you commit. Request a free estimate to start.
DADU rental income — common questions
How much rent can a Seattle DADU earn?
Most rent for roughly $1,800–$2,800/month long-term unfurnished, depending on size, neighborhood and finish. Furnished mid-term rentals can earn more but carry higher vacancy and management effort.
How do people finance a DADU?
Cash-out refinance or HELOC against existing equity, a renovation loan against after-completion value, or a dedicated ADU/construction loan. Some lenders count projected rent toward qualifying income — ask early.
Does a DADU increase property value?
Generally yes — a permitted, legal DADU adds finished rentable square footage and an income stream that appraisers and buyers value. The exact lift depends on the appraisal approach and neighborhood.
How long until it pays for itself?
Rent-alone payback often runs 10–18 years, but that ignores property-value gain and appreciation. Folding those in, the effective return is usually much faster. The honest answer is lot-specific.