Serving Washington
ADU Builder in Redmond, WA: A Second Unit That Pays for Itself
Bayside Home Builders designs, permits, and builds accessory dwelling units in Redmond from a single point of contact, so you get one team accountable for the whole project.
adu project · RedmondRedmond Lots Have Room. Most Homeowners Never Use It.
A typical Redmond backyard can fit a 600 to 800 square foot detached cottage. That is a rentable unit, a space for aging parents, or a home office with a full bath. Most homeowners leave that value sitting unused because the permit process feels complicated and contractor quotes vary wildly with no explanation.
What you are living with
You keep mowing that backyard while a mortgage-offsetting rental sits unbuilt. Or you pay for assisted living or a separate apartment for a family member when a backyard cottage would solve the same problem at a fraction of the long-term cost.
What you get instead
We walk your lot first, tell you what is actually buildable under Redmond zoning, and give you a real number before you commit to anything. No design fees until you decide to move forward.
Our Recent Work
Accessory Dwelling Units Built to Code, Built to Last
An ADU adds livable square footage to your property without touching your primary residence. Whether you need a rental unit, a space for aging parents, or a home office with a bathroom and kitchenette, we design and build the structure from the ground up, handling permitting, utilities, and inspections so you do not have to coordinate between multiple contractors.
Site Evaluation and Feasibility
Before any plans are drawn, we walk your property and review zoning rules, setback requirements, lot coverage limits, and utility connection points. You get a clear yes or no on what is buildable before spending money on design.
Architectural Design and Permit Drawings
Our in-house design team produces permit-ready drawings sized and positioned to satisfy local zoning. We handle the permit application and communicate directly with the building department through review and approval.
Foundation and Structural Framing
We pour the foundation appropriate to your soil conditions and frame the structure to current residential building code. Every framing inspection is passed before we close up walls.
Mechanical, Electrical, and Plumbing Rough-In
Licensed subcontractors install the electrical panel, plumbing supply and drain lines, and HVAC or mini-split system. We coordinate the inspection schedule so each trade is signed off in sequence without delays.
Interior Finishes and Fixtures
Insulation, drywall, flooring, cabinetry, countertops, and fixtures are all included in our scope. You select finishes from our supplier network. We install and trim out everything to a move-in ready standard.
Final Inspections and Certificate of Occupancy
We schedule and pass every final inspection, including building, electrical, plumbing, and mechanical, and hand you the certificate of occupancy so the unit is legal to rent or occupy from day one.
Why Homeowners Choose Bayside for ADU Projects
ADUs require a contractor who can manage design, permitting, and construction as a single coordinated process. Here is what separates the way we work from hiring a general contractor who subs out the design.
Design and Construction Under One Roof
We employ our own designers and run our own crews. When a permit reviewer asks for a revision or a field condition changes the plan, the same team that drew the plans adjusts them the same week. There is no finger-pointing between a separate architect and a separate builder.
Licensed and Bonded, Washington L&I
We carry active WA L&I licensing and full bonding. You can verify our license number directly with the state before signing anything. We will not ask you to pull your own permits or list yourself as the owner-builder to cut costs.
Permit Experience Across Multiple Jurisdictions
ADU rules differ from one municipality to the next. We have navigated varying setback rules, owner-occupancy requirements, and utility connection standards across multiple jurisdictions. We know what reviewers flag and we write plans that pass on the first or second submission, not the fifth.
Fixed-Scope Contracts with Itemized Budgets
We provide a written contract with a line-item budget before work begins. Allowances for finishes are called out explicitly so you know exactly what is included. Change orders require your written approval before any additional work proceeds.
What our clients say
We hired Bayside for a full home remodel, and the results are absolutely breathtaking! Coral was our project manager and did an outstanding job coordinating the team and managing every aspect of the project. The new open-concept living space and…
Bayside transformed our entire house into something straight out of a magazine! Coral, our project manager, was an absolute gem, organized, communicative, and attentive to every detail. From the new flooring to the redesigned layout, everything was…
How an ADU Project Works with Bayside
Most ADU projects follow the same four-phase sequence from first conversation to move-in ready. Here is what to expect at each stage.
Discovery and Feasibility
We meet at your property, review your lot dimensions and zoning classification, and assess your utility stub locations. You leave that meeting knowing whether an ADU is feasible, what size is realistic, and what the permitting process will look like. No fee for this first conversation.
Design, Pricing, and Permitting
Once you decide to move forward, we produce a detailed scope, a fixed-price contract, and permit-ready drawings. We submit the permit application and manage the back-and-forth with the building department. This phase typically takes several weeks depending on local review times.
Construction
We break ground after permit approval is in hand. Our project manager updates you weekly and is reachable by phone or text throughout the build. We schedule each inspection proactively so the project does not sit idle waiting for a sign-off.
Final Walkthrough and Turnover
Before we hand over keys, we walk the completed unit with you and create a punch list of any items to address. You receive the certificate of occupancy, warranty documentation, and contact information for ongoing support. The unit is ready to occupy or rent.
What Adu Costs
ADU costs in Redmond depend on the project type, your lot conditions, and how far through the City of Redmond permitting process your plans need to go.
Attached ADU
Converting or adding living space within the existing footprint.
Garage conversion
Turning an existing garage into a permitted dwelling.
Detached DADU
A standalone backyard cottage, built to code and permitted.
Redmond reviews custom ADU designs in roughly 3 to 5 weeks, which is faster than many King County jurisdictions but still affects your start date and carrying costs. The city allows one ADU per residential lot in all residential zones, with detached units capped around 800 to 900 square feet, so your square footage ceiling is set before we talk finishes or systems. Older Redmond housing stock, split-levels and 1960s ramblers especially, often needs electrical panel upgrades or crawlspace work that a price quote based only on floor plan square footage will miss.
ADU Contractor in Redmond, WA
Redmond allows one ADU on each residential lot in all single-family zones. That includes both attached units and detached backyard cottages. We handle design, permits, and construction so you deal with one team from site visit to final inspection.
Permits & review
Redmond reviews ADU permits under RMC Title 21. Custom designs typically take 3 to 5 weeks for city review. ADUs are generally capped at 800 to 900 square feet depending on lot size and configuration. We prepare a complete permit package upfront to avoid back-and-forth corrections that stretch timelines.
Housing stock
Most Redmond lots are mid-century to 1990s single-family homes on standard King County parcels. Backyards often have enough room for a detached ADU, but setbacks, tree canopy regulations, and utility connections are the details that determine feasibility before you spend anything on design.
Areas we serve
We build ADUs throughout Redmond and the surrounding Eastside, including Bellevue, Kirkland, Sammamish, and Issaquah. If you are in King County east of Seattle, we can take on your project.
Common questions
How large can an ADU be in Redmond, Washington?
Redmond's zoning code allows one ADU per residential lot in all residential zones, with finished space generally capped at 800 to 900 square feet depending on your specific lot and zone. A detached ADU also has to meet setback and lot coverage limits that vary by parcel. The practical first step is a site review, because your lot dimensions and existing structures can tighten that number before design ever starts.
What does it cost to build an ADU in Redmond?
A detached ADU in Redmond typically runs $250,000 to $450,000 fully built out, including design, permits, site work, and construction. Attached ADUs and garage conversions usually land lower in that range. The spread is wide because Redmond lots vary a lot, utility connections range from straightforward to expensive, and finish level matters. We will walk you through a site-specific budget estimate before you commit to anything.
What is the cheapest way to build an ADU in Redmond?
A garage conversion or a basement conversion is almost always the lowest-cost path because the shell already exists and you are not paying for a new foundation, framing, or roof. After that, an attached addition typically costs less than a fully detached backyard cottage. Where homeowners spend more than they planned is on upgrading the electrical panel, adding a separate sewer lateral, and meeting current energy code, all of which apply regardless of which route you take. Knowing those fixed costs upfront keeps budgets realistic.
What are the real drawbacks of building an ADU?
The honest drawbacks are upfront cost, timeline, and complexity. Permitting in Redmond takes several weeks for a custom design, construction typically runs 6 to 12 months depending on scope, and carrying costs add up during that period. You may also need to upgrade your electrical service or add a separate utility meter, which adds cost that first-time ADU owners often miss. If your lot has steep grade or tight setbacks, site work costs climb fast. None of these are reasons to skip the project, but they are reasons to plan with accurate numbers from the start.
How long does the ADU permit process take in Redmond?
City of Redmond reviews custom ADU designs in roughly 3 to 5 weeks for an initial response, with additional rounds if corrections are required. Total permit timeline from submission to approval commonly runs 2 to 4 months for a straightforward detached ADU. More complex projects with variances or utility work take longer. We handle all permit submissions and city correspondence on your behalf so you are not managing that back and forth yourself.
Do I need a separate address or utilities for my Redmond ADU?
You can share a water and sewer connection with the primary home in many cases, which keeps costs down. A separate address is assigned by the city and is required if the unit will be rented. Separate electrical metering is sometimes required and sometimes optional depending on your existing service and how the unit is used. We sort through these questions during feasibility so there are no surprises during construction.
Can I rent out an ADU in Redmond?
Yes. Redmond allows ADUs to be rented in all residential zones. There is no owner-occupancy requirement under current city rules, meaning you do not have to live on the property to rent the ADU. Rental income potential depends on unit size, finish, and location within Redmond, and we can share what similar units in the area are renting for so you can run real numbers on your return.
Keep exploring
Other services in Redmond
Bathroom Remodeling→Kitchen Remodeling→Home Renovation→Home Addition→Home Builders→
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