Looking for a custom home builder in Mercer Island, WA? Describe your project once and up to three custom home builders who work in Mercer Island and King County get back to you with a quote. It's free and there is no obligation.
Mercer Island is home to about 25,302 people (2024 Census Bureau estimate), a shrinking community (−1.8% since 2020). With 3,964 people per sq mi, it is a densely built-up area. Infill lots, teardowns and acreage on the edge of town are where custom homes get built here.
Mercer Island at a glance
- Population (Census Bureau estimate, 2024)
- 25,302 (−1.8% since 2020)
- Rank in Washington
- 45th of 281 cities and towns
- Land area
- 6.4 sq mi
- Population density
- 3,964 people per sq mi (densely built-up)
- Type
- City (Mercer Island city)
- Main county
- King County
What to check before hiring in Mercer Island
- License: in Washington, check the builder's license or registration.
- Site costs: utilities, septic, wells and driveways can add significantly.
- Contract: compare allowances and change-order rules, not just the total.
- References: visit homes the builder has finished.
Useful official resources
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NAHB: National Association of Home Builders
Official information and guidance.
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ICC: International Code Council
Official information and guidance.
Services available in Mercer Island
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Custom home construction
Construction of a custom home on the owner's lot, from permit to move-in.
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Design-build
Builder who handles both the design and the construction of the home.
Frequently asked questions in Mercer Island
How much does a custom home cost in Mercer Island, WA?
It depends on size, finishes and site costs. Describe your project: builders who serve Mercer Island reply with a quote.
How long do permits take?
From weeks to months depending on the jurisdiction.
Can I use my own plans?
Yes; builders price them and suggest changes if needed.
Which custom home builders will contact me?
Up to three independent custom home builders who serve Mercer Island and the surrounding area, chosen for the service you need. Your details are shared only with your consent.
Source: U.S. Census Bureau, Population Estimates Program (Vintage 2024) and Gazetteer Files (public domain), imported on 10/31/2026. Figures describe the incorporated place or county as published; they are shown for information only.