With 34 years on the Eastside, Tennyson Homes is your expert builder for Accessory Dwelling Units (ADUs) and Detached Accessory Dwelling Units (DADUs).
Years on the Eastside
Family-Owned, Since
Master Builders Association Member
Referral & Repeat-Client Driven
More Eastside homeowners are exploring ADU builds since the 2024 code updates, but the homeowners who actually succeed are the ones who pick a builder with deep local knowledge. Tennyson Homes has worked across Kirkland, Bellevue, and Mercer Island since 1992. We’ve learned which lots support which projects, where each jurisdiction draws its lines, and how to design ADUs that move through the approval process without surprises.
Our integrated team manages your entire ADU project from the first permit application to the final punchlist, with a clear process focused on your goals, whether that’s generating rental income, creating space for multigenerational living, or increasing long-term property value.
An ADU or DADU is a smart way to get more out of your property without buying more land. These secondary homes give you valuable extra space, whether for family or for rental, adapting to your needs over time. From backyard cottages to in-law suites, here are the key benefits of adding a new dwelling unit to your Eastside lot.
Rental Income
Generate a steady income from your existing lot without buying more property. A well-built ADU can be a strong rental asset across Kirkland, Bellevue, and Mercer Island.
Multigenerational Living
Keep family close with a private, self-contained space. An ADU works for aging parents or adult children, offering proximity without giving up independence on either side.
Long-Term Value
ADUs and DADUs are recognized by appraisers as income-generating assets, raising the resale value of your property on the competitive Eastside market.
Updated ADU Rules
Recent zoning changes opened the door for more homeowners. Cities across the Eastside relaxed owner-occupancy requirements and simplified permitting, making this the most accessible time to build.
We provide a full-scope, turnkey service that covers every aspect of your ADU or DADU project. Our process is designed to eliminate stress and give you confidence that every detail is accounted for.
From the first walkthrough to the final punchlist, we own every phase of your remodel. That includes architect coordination (yours or ours), structural and trade permits, demolition through finish work, and inspections at every stage. No coordination gaps, no need to chase separate contractors.
We handle every permit your remodel needs (Kirkland, Bellevue, Mercer Island, and King County), including the coordination required when a project crosses multiple trade categories.
Our skilled tradespeople work together under our direct supervision. You never have to manage separate contracts or deal with finger-pointing between subs.
Gain access to our vetted network of suppliers with expert guidance on selecting finishes matched to your goal, whether that's long-term livability or maximum resale return.
ADU builds have permit complexities and lot constraints that catch first-time owner-builders off guard. Our 7-step process exists to handle that complexity for you, so the ADU code rules, utility tie-ins, lot coverage limits, and inspection timing are all someone else’s problem. You make the design and finish decisions, and we handle everything in between.
Most ADU clients build on land they already own. If you’re considering an investment-driven ADU build on a new parcel, we can help you find a lot that supports ADU development under current Kirkland or county codes, including the lot coverage, setback, and parking requirements that often disqualify otherwise-attractive properties.
We evaluate your lot for ADU feasibility, configuration, zoning, ADU code compliance, and site conditions, before a dollar is committed.
Early consultations to establish your ADU scope, goals, and budget, whether you’re focused on rental income, multigenerational living, or resale value.
ADU plan review is where rental-grade versus luxury-grade decisions take shape and where we catch the small things that drive surprise costs, like utility tie-in routing, kitchen scope, and bathroom count. We walk you through architectural drawings, site plans, and specifications with real cost numbers at every stage.
Select your finishes, fixtures, and materials with support from our design team, scaled to your goal, rental-grade or luxury.
Professional, high-touch communication throughout the build with real-time project updates and direct access to your project manager.
Move in with confidence. We handle the certificate of occupancy and post-construction support so your ADU is ready from day one.
Our deep experience across the Eastside gives us an unmatched understanding of each community’s unique building environment and regulations.
Choosing the right builder is the most important decision you’ll make for your ADU project. We combine decades of local experience with a clear, accountable process, so you get a builder you can trust and a finished ADU built to last.
Decades on the Eastside
34 years of building in Kirkland, Bellevue, and Mercer Island means we know every jurisdiction's permit office, every common ADU code pitfall, and every shortcut that holds up to inspection. That experience is your assurance that the project gets built right the first time.
Builder Accountability
One team, one contract, and one point of contact from site assessment to final walkthrough. No gaps between architect, GC, and subs.
Permitting Expertise
Many ADU projects stall at the permit stage. We manage it directly across the Eastside, drawing on working relationships with permit offices in Kirkland, Bellevue, Mercer Island, and King County to keep things moving.
Rental, In-Law, or Luxury
We adapt the finish spec to your end use without compromising the underlying build. The same craftsmanship goes into every ADU.
Our reputation rests on referrals and repeat clients, which is rare for an ADU project that’s often a one-time build. We hold every ADU project to the same standard we’d apply to our own property.
An ADU (Accessory Dwelling Unit) is a secondary living space on the same lot as a primary home, which can be attached (like a basement apartment) or detached. A DADU (Detached Accessory Dwelling Unit) is always a separate structure, often called a backyard cottage or carriage house. Both are designed to be complete, independent living spaces.
The timeline depends on project complexity, permitting, and site conditions. Generally, you can expect the process to take 9-12 months from initial design to final completion. The permitting phase can be a significant variable, which is why our expertise in this area is so valuable for keeping projects on track.
The cost to build an ADU varies widely based on size, type (attached vs. detached), site conditions, and the level of finishes. Projects typically range from $275,000 to $400,000 or more. We provide a detailed budget after the initial design and feasibility phase.
Yes, all new ADU and DADU construction requires permits from your local jurisdiction, such as the City of Kirkland or King County. A major benefit of the 2024 code changes in Kirkland is that owner-occupancy is no longer required, making it easier for property owners to build and rent these units.
Absolutely. Once we complete the final walkthrough and the city issues a certificate of occupancy, your ADU is officially a legal dwelling. You can move in a tenant or family member right away.
Yes, adding a valuable structure like an ADU will increase the assessed value of your property, which will lead to an increase in your property taxes. However, for many homeowners, this increase is more than offset by the rental income generated or the added flexibility and value the space provides.
Tennyson Homes has helped Eastside families build the spaces they need for the lives they want. Let us put our expertise to work for you. Contact us to discuss your vision and learn how an ADU can enhance your property. Call us at (206) 914-5970 or fill out our contact form to get started. Our team will follow up within one business day.
