DADU / ADU CONSTRUCTION

Seattle DADU & ADU Builders

Seattle's ADU regulations have created incredible opportunities for homeowners. Whether you're looking to generate rental income, create space for aging parents, house adult children, or build a private home office, a DADU or ADU can transform how you use your property.

At Waltier Homes, we've become specialists in Seattle's ADU market. We understand the regulations, the permitting process, and the design considerations that make these projects successful.

From backyard cottages to basement conversions, we handle every aspect of your ADU project — permitting, design, construction, and final inspection.

Types

Two paths forward

Choose the unit that works for your property.

DADU (Detached Accessory Dwelling Unit)

A standalone structure separate from your main home — often called a backyard cottage, carriage house, or laneway home. DADUs offer complete privacy and independence for occupants while maximizing your property's potential.

Separate structure

$350k–$650k+

Full independence

Yes

Flexible layouts

Yes

Rental potential

High

400-1,000 sq ft (Seattle allows up to 1,000 sq ft in most zones)
Full kitchen, bathroom, and living space
Private entrance and outdoor space
Can include garage or carport
Ideal for rental income or multigenerational living400-1,000 sq ft (Seattle allows up to 1,000 sq ft in most zones)

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AADU (Attached Accessory Dwelling Unit)

A self-contained unit within or attached to your existing home — commonly a basement conversion, garage conversion, or addition. AADUs typically cost less than DADUs while still providing independent living space.

Separate structure

$150k–$350k+

Shared utilities

Yes

Efficient use

Yes

Rental income

Good

Basement apartment conversions
Garage conversions
Above-garage units
Home additions with separate entrance
Internal conversions of existing space

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Services

Three ways we Build

Thoughtful updates that honor what came before

Rental Income

Seattle's rental market remains strong. A well-designed ADU can generate $1,500-$3,000+ per month in rental income, helping offset your mortgage or fund other investments.

Multi-Gen Living

Keep family close while maintaining independence. ADUs are perfect for aging parents who want proximity without giving up privacy, or adult children transitioning to independence.

Property Value

A permitted, well-built ADU significantly increases your property's value. You're not just building a structure — you're building equity.

Flexible Use

Home office, art studio, guest house, rental unit — an ADU adapts to your changing needs over time.

The Process

Our ADU Process

Design and Planning

Whether you choose a pre-approved Seattle DADU plan or a custom design, we'll help you create a space that maximizes functionality within your budget.

Construction

Our experienced crews build your ADU efficiently and to code. You'll receive regular updates and have direct access to your project manager throughout.

Feasibility Assessment

We start by evaluating your property. What can you build? Where can you build it? What will it realistically cost? We'll give you honest answers before you commit to anything.

Permitting

Seattle's ADU permitting has improved, but it still requires expertise. We handle all documentation, coordinate with the city, and keep the process moving.