Guides, tips, and insights on building ADUs and DADUs in the Seattle and Tacoma area.
Before you can price a project, you need to know how much house you're allowed to build. Here's what Washington's HB 1337 requires cities to permit for ADU size, height, and setbacks, and how to confirm the exact numbers for your lot.
Read More →A finished-out basement is one of the least disruptive ways to add an accessory dwelling unit — you already have the shell, the roof, and the foundation. But turning below-grade space into a legal, rentable unit hinges on a few specific code items that trip up most homeowners: ceiling height, egress, and a compliant separate entrance.
Read More →Once you've decided to build an accessory dwelling unit, the next big fork in the road is how it gets built: manufactured off-site and craned into place, or framed stick-by-stick in your backyard. Each path has real trade-offs in timeline, cost, and flexibility.
Read More →Now that coach houses are legal again across most of Chicago, the first question every homeowner asks is what one actually costs. The honest answer is a wide range, and the reasons it's wide are exactly what you need to understand before you plan a project.
Read More →Rent is one way an ADU pays you back. Resale value is the other. Here's how appraisers in Washington treat an accessory unit, why permits decide whether it counts, and how to think about the equity you're building.
Read More →For most of Massachusetts, adding a backyard cottage or in-law suite used to mean a special permit, a public hearing, and a real chance of rejection. The Affordable Homes Act ended that. Here's what changed, what you're now allowed to build, and what it costs.
Read More →Right after cost and timeline, most homeowners ask the same question: will an ADU spike my property taxes? Here's how Washington assessors treat new construction, what really changes on your bill, and where to get a real number.
Read More →Most Washington homeowners underestimate the calendar, not the budget. Here's a realistic phase-by-phase timeline for an ADU, from first drawings to final inspection, and what actually controls the pace.
Read More →Build a rental ADU and your standard homeowners policy may not cover the part of your property that now earns income. Here's the coverage gap most Washington homeowners don't find out about until they file a claim.
Read More →For decades, building a coach house in Chicago was effectively illegal. That changed on April 1, 2026, when the city's permanent additional dwelling unit ordinance took effect, opening backyard and basement units to a majority of the city for the first time since the 1950s.
Read More →A six-figure ADU only makes sense if you know what it earns back. Here's what detached ADUs rent for across Seattle and Tacoma, and how to run the ROI math before you build.
Read More →Once you've settled on a design and a builder, the next question is almost always the same: how do I actually pay for this? An ADU is a six-figure investment, and the way you finance it shapes your monthly cost, your timeline, and your return.
Read More →Bellevue and the wider Eastside have become one of the most active ADU markets in the Puget Sound region. High land values, strong rental demand, and Washington's HB 1337 reforms have made backyard cottages a smart move — but choosing the right builder for an expensive market matters more than ever.
Read More →House Bill 1337 is the most significant piece of ADU legislation Washington state has ever passed. Signed into law by Governor Jay Inslee in May 2023, this bill fundamentally reshaped the rules around accessory dwelling units across the state.
Read More →Tacoma has quietly become one of the best cities in Washington for building a detached accessory dwelling unit, with lower construction costs than Seattle, a growing pool of experienced DADU contractors, and city regulations that actively encourage backyard cottage development.
Read More →One of the first questions every homeowner asks when considering an accessory dwelling unit is: how much is this going to cost? The answer depends on the type of ADU you're building, your location in Washington state, the size and finishes you choose, and your site conditions.
Read More →Choosing the right contractor is one of the most important decisions you'll make during your ADU project. The builder you hire will directly affect your costs, timeline, quality, and overall experience.
Read More →Seattle has become one of the most ADU-friendly cities in Washington state, but the permitting process still involves multiple steps, specific requirements, and real costs. If you're planning to build an ADU or DADU in Seattle, here's a clear breakdown of what to expect.
Read More →Seattle's ADU boom shows no signs of slowing down. Since Washington passed HB 1337 in 2023, permit applications for backyard cottages and accessory dwelling units have surged across the city — and finding the right builder can be overwhelming.
Read More →Building an accessory dwelling unit is a significant investment, and getting your budget right from the start can mean the difference between a smooth project and a stressful one. Whether you're planning a basement conversion or a new backyard cottage in the Seattle-Tacoma area, here's a detailed breakdown of the costs you should plan for.
Read More →Not every ADU project requires building from the ground up. If you have a detached or attached garage that's mostly storing old bikes and holiday decorations, converting it into a livable accessory dwelling unit is one of the most cost-effective ways to add value, rental income, and usable space to your property.
Read More →Accessory dwelling units have gone from niche housing curiosity to mainstream building trend across the Puget Sound. Permit applications for ADUs in Seattle have increased dramatically over the past several years, and several converging factors suggest the trend is just getting started.
Read More →If you're thinking about adding an accessory dwelling unit to your property in the Seattle or Tacoma area, one of the first decisions you'll face is whether to build an attached ADU (AADU) or a detached accessory dwelling unit (DADU). Both options can add living space, generate rental income, and increase property value, but they differ significantly in cost, design flexibility, and permitting requirements.
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