Additions
More room built onto your home and tied into its existing foundation, roof and systems, with septic, setbacks and critical areas checked before design.
Residential
ADU and DADU construction in Kitsap
Detached cottages, attached units and garage or basement conversions, with zoning, utilities and septic or sewer reviewed before design.
Who this is for
This service is for owners who want a second home on their lot: a backyard cottage for family, a rental, a place for a caregiver or a guest suite, a basement or garage converted into a unit. State law has pushed cities and counties to allow ADUs, but local rules still decide size, parking, utilities and design details. We help you find out what applies to your parcel, then build it.
What's included
- A parcel review: zoning, setbacks, lot coverage, utilities, septic or sewer capacity and any critical areas
- A choice among a detached unit, an attached unit, or a garage or basement conversion, with the trade-offs laid out
- Coordination with your designer and engineer for drawings, structure and site plan
- Septic or sewer connection planning, including Kitsap Public Health District review where the lot has septic
- Water, power, and sewer or septic service, with trenching and meter work scheduled with the providers
- Permit application with the city or county
- Foundation, framing, envelope and systems built to the Washington State Energy Code
- Finishes, a walkthrough and a closeout
How the work runs
Step 1: Parcel review
We check zoning, setbacks, utilities and septic or sewer, and work out which kind of unit your lot can take.
Step 2: Design and budget
The drawings and the estimate develop together, with utilities and site work priced as their own lines.
Step 3: Permit
One application to the city or county, with septic, critical-area or shoreline reviews alongside where they apply.
Step 4: Site and structure
Trenching and utilities, foundation, framing and dry-in, on a schedule that protects the main house and yard.
Step 5: Finish and handover
Systems, insulation, finishes and inspections, then a walkthrough, punch list and handover.
On the Kitsap Peninsula
ADU rules are set locally, so the same backyard cottage is a different project in different places. The City of Poulsbo, the City of Bainbridge Island, Bremerton and Port Orchard each write their own rules, and Kitsap County writes them for Kingston, Silverdale, Suquamish and the other unincorporated communities. Our permit guides link to each authority's own pages.
Utilities are usually the deciding factor. On a lot with public sewer, an ADU is a new connection. On a septic lot, Kitsap Public Health District reviews whether the system can serve another dwelling, and a second system or an upgrade can become a major part of the budget. Water works the same way: a city or district connection, a shared well, or a new well.
Detached units need a site plan that respects setbacks, trees and slopes. Garage and basement conversions depend on ceiling height, egress and the structure already there. When the yard is going to be opened for trenching, we plan the work around the wet season.
Permit guides
The office that issues the permit depends on the parcel. Start with the authority that covers yours.
What it costs
The Estimate Desk gives a planning band for an ADU: a detached cottage, an attached unit, or a garage conversion, with drawings and a permit allowance shown as lines, not footnotes. It is a planning band, not a bid, and a site visit sets the number.
What moves an ADU's price: the type of unit, its size, how far the utilities have to run, septic or sewer work, the foundation, the finish level, and design and permit fees. On a septic lot, the system is often the largest unknown, and we raise it first.
Price it first
The Estimate Desk gives a planning band, not a bid. A site visit sets the number.
Questions about this work
Can I build an ADU if my home is on septic?
Often, but the septic system has to be able to serve a second dwelling. Kitsap Public Health District reviews that, and the answer may be an upgrade or a new system. We raise septic first because it can shape the whole project.
What is the difference between an ADU and a DADU?
An ADU is an accessory dwelling unit; it can be attached to the house or inside it. A DADU is a detached ADU, a separate building on the lot, such as a backyard cottage. Both are small, complete homes with their own kitchen and bath.
Can I convert my garage into an ADU?
Often. A garage conversion depends on ceiling height, the slab, insulation, egress, and whether you need to replace parking under local rules. We review the garage and the local requirements before you commit.
Can I rent out my ADU?
Long-term rental is a common reason people build one. Short-term rental, owner-occupancy and parking rules are set locally and can change, so confirm with your jurisdiction. Our permit guides link to the local pages.
How long does an ADU take to build?
It depends on the permit review, the utility work and the season. We give you a schedule with the estimate, and we do not promise a number of weeks before we have seen the site and the plans.
Do I need separate utility meters for an ADU?
It depends on the jurisdiction and the utility providers. Some require separate meters or connections; others allow shared service. We confirm with the providers during planning, since it affects trenching and cost.
Does an ADU have to match my house?
Sometimes local design standards ask for similar materials or roof forms, and sometimes they do not. Even where they do not, many owners match siding and trim so the lot looks like one property. We cover the options when we review your parcel.
Talk with us about ADUs and DADUs
Call Ian Laughlin at (206) 226-1988, or send the details and we will set up a site visit.