ADU Construction in White Center
Professional adu construction services in White Center and surrounding areas • Licensed & Insured • Free estimates
ADU Construction Services in White Center
ADU design
Permit processing
Foundation work
Complete construction
Why Choose TopVolk Construction LLC in White Center?
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Fully licensed contractor with comprehensive insurance coverage for your peace of mind.
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Serving White Center and surrounding areas with fast response times and local expertise.
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Work directly with Vladislav - no middlemen, clear expectations, honest recommendations.
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100+ projects completed since 2023. We pay $100 for every day past the agreed deadline.
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Materials are billed separately and are not included in the discount.
TopVolk Construction builds DADUs, attached ADUs, and basement conversions in White Center, Washington — permitted through King County DPER, under WA HB 1337.
Last updated August 2026
White Center ADU Construction — DADUs on King County Lots
Backyard cottages, attached additions, and basement conversion ADUs in White Center all get designed and built by TopVolk Construction, owner-led by Vladislav Volkov — but the permit paperwork runs through King County DPER, not Seattle SDCI, since this stretch of zip codes 98106 and 98146 has stayed unincorporated county land rather than getting annexed into Seattle. That distinction catches people off guard near Steve Cox Memorial Park, where a homeowner assumed her DADU application would land on the same portal as her sister's project a few blocks over in West Seattle proper. It doesn't. Under WA HB 1337, most single-family lots here qualify for up to two ADUs — a detached unit behind the house plus an attached unit or basement conversion — which matters in a neighborhood where a lot of post-war ramblers near Shorewood and Boulevard Park already have crawlspace foundations built for exactly this kind of retrofit. TopVolk has completed 100+ projects across King, Snohomish, Pierce, and Kitsap counties since 2023, and a good chunk of the DADUs run on Mitsubishi mini-splits instead of ducted furnaces because the units are small enough that a single head handles heating and cooling year-round.
White Center's housing stock skews older than people expect — plenty of 1940s and '50s bungalows on 98106 lots near Gregory Heights, plus a run of 1960s ramblers toward 98146 closer to the Burien line, most sitting on foundations poured before anyone thought about ADUs. Lots here tend to run 5,000 to 7,200 square feet, narrow and often sloped toward the Duwamish valley, which changes the math on where a DADU can sit once you subtract setbacks and lot coverage limits. Because White Center is unincorporated, every ADU project routes through King County DPER for plan review and inspections, not a city permit counter — plan review here typically runs 8 to 14 weeks depending on how busy the office is that quarter. The RapidRide H Line running along 16th Ave SW gives some lots near that corridor a parking exemption for the new unit, which is worth checking before assuming a second driveway pad is required. Homes built before 1978 also trigger a lead-based paint assessment if a basement conversion disturbs old plaster, something DPER flags during plan review.
Common ADU Construction Concerns in White Center
DADU vs. Attached ADU vs. Basement Conversion
Most calls start with 'which kind of ADU should I build,' and in White Center the answer usually comes down to what's under the house. A lot of the ramblers near Boulevard Park sit on 3-foot crawlspaces — too tight for a basement conversion without excavation, which pushes homeowners toward a detached unit instead. Where there's an actual basement with 7-foot ceilings, we're often cutting in a new LVL beam to open the layout, sistering joists where the old Douglas-fir framing has sagged, and running a separate Rinnai tankless unit so the ADU doesn't share hot water with the main house. A DADU in the backyard usually pencils out at $180K–$240K depending on utility runs; a basement conversion is often $90K–$150K since the shell already exists. Either path takes 4-7 months end to end once King County DPER permits clear.
Utility Separation: Shared Meter or Second Connection
King County DPER wants clarity on how the new unit gets water, sewer, and power before signing off on plan review. A detached ADU behind a Shorewood lot can often share the existing water meter with a sub-meter, but sewer is trickier — if the basement bathroom sits below the main line's invert elevation, that means an ejector pump, not gravity flow. We've run into this on more than one Gregory Heights project where the original galvanized supply line needed replacing anyway, so it made sense to swap in copper and set new Moen fixtures at the same time. Trenching for a second electrical panel and water line typically adds $8K-$15K to a DADU budget depending on trench length and whether crews hit rock or old fill. Getting this scoped during pre-design avoids change orders once excavation starts.
King County DPER Plan Review, Setbacks, and the 24-Foot Height Limit
Because White Center never got annexed, ADU permits here go through King County DPER instead of Seattle SDCI or a city permit counter — different forms, different review queue, different standard details on the plan set. A detached ADU is capped at 24 feet in height, has to clear rear and side setbacks, and can't push total lot coverage past what the parcel's zoning allows. WA HB 1337 opened the door to two ADUs per lot statewide, but DPER still checks each project against King County's setback and coverage tables lot by lot. Parcels within a quarter mile of the RapidRide H Line corridor on 16th Ave SW may qualify for a parking exemption, which matters on narrow lots where a second parking pad isn't realistic. TopVolk is a WA Licensed Contractor and handles the full plan review submission — Vladislav prepares the site plan and elevations directly, no third-party permit runner involved.
What a White Center ADU Actually Costs
Line-item quotes for a DADU in White Center usually land between $170K and $260K, and the swing depends on slope, utility distance from the street, and finish level — a kitchenette with semi-custom cabinets, quartz counters, and a GE range costs more than one with IKEA cabinets, laminate, and a Samsung fridge, but the bigger driver is almost always site work. A lot backing toward the Duwamish valley grade needs more retaining and drainage than a flat lot near Evergreen High School. Basement conversions run cheaper, typically $90K-$160K, since the foundation and roof already exist. Every TopVolk contract has a deadline written in with a penalty if we miss it — not a verbal promise, an actual clause — and pricing comes as a line-item quote, not a ballpark range. Call (206) 591-1096 for a free on-site consultation and an exact number for your lot.
Keeping the ADU Dry and Comfortable Through PNW Winters
A DADU roof facing north toward the alley picks up moss fast in White Center's wet season — 37 inches of rain a year will do that, especially October through May. Hardie siding goes over cedar on most builds now, since cement board shrugs off the moisture better and doesn't need refinishing every few years. Attic insulation goes in at R-49 minimum, well above older code minimums, which keeps heating bills reasonable when the ADU runs on a single Mitsubishi mini-split instead of a full furnace. Crawlspace vapor barriers are non-negotiable on the older ramblers — skip it and mildew shows up under the subfloor within two winters. Plan to hose off gutters and check the roof for moss twice a year; the mini-split filter needs a rinse every few months if anyone in the unit has pets.
Frequently Asked Questions
How fast can you get to White Center for Adu Construction?▼
White Center sits just off Highway 509 and Ambaum Blvd SW, close enough to TopVolk's usual project radius in Seattle Metro that an on-site DADU consultation usually gets scheduled within a week of the call. Parking on the narrow residential streets near Boulevard Park is tight, so we ask homeowners to have a spot cleared or note if street parking is available before the visit. Once a contract's signed, design and permitting through King County DPER typically run 8-14 weeks before construction starts. Call (206) 591-1096 to get a visit on the calendar.
What does an ADU cost in White Center?▼
A detached ADU typically runs $170K-$260K depending on site work, utility trenching, and finish level, while a basement conversion usually lands at $90K-$160K since the existing foundation and roof cut a big chunk of cost. Slope, distance from the street for utility runs, and cabinet or appliance choices all move the number. TopVolk gives line-item pricing, not a vague range, after a free on-site walkthrough with Vladislav directly. Most quotes are ready within a few days of that visit, with no sales pressure attached.
What's the permit process for an ADU in White Center?▼
White Center is unincorporated King County, so every ADU permit — detached, attached, or basement conversion — goes through King County DPER, not Seattle SDCI. Plan review typically takes 8-14 weeks, and DPER checks the site plan against setback, height (24 feet for a DADU), and lot coverage rules specific to the parcel's zoning. TopVolk is a WA Licensed Contractor and prepares the full submission package — site plan, elevations, and construction drawings — so homeowners aren't shuffling paperwork between an architect and a permit runner. Rough-in and final inspections follow the same DPER inspector assigned to the parcel through the whole build.
Can a basement conversion in White Center legally become an ADU?▼
Yes, as long as the space meets King County's ceiling height and egress requirements — generally 7 feet of clear ceiling height and a code-compliant egress window or door in the sleeping area. Older White Center basements often need a new egress window cut into the foundation wall, plus a vapor barrier and DriCore subfloor if there's any moisture history. TopVolk also confirms the sewer line's invert elevation early, since a bathroom below that line needs an ejector pump rather than gravity drainage. Most basement ADU conversions in the area take 3-5 months once permits are in hand.
How long will a White Center ADU last, and what's covered under warranty?▼
Built to current IRC code with Hardie siding, R-49 attic insulation, and a properly detailed vapor barrier, a DADU here should perform for decades like any well-built single-family home in the Pacific Northwest. TopVolk backs workmanship on every project, and manufacturer warranties carry through separately on equipment like the Mitsubishi mini-split, Rinnai water heater, or Milgard windows installed. What's not covered is normal wear — roof moss, gutter buildup, filter changes — the maintenance every PNW homeowner already deals with. Ask during the consultation what's covered in writing before signing anything.
Do you build ADUs outside White Center too?▼
TopVolk covers the whole Seattle Metro area — White Center, Burien, West Seattle, Tukwila, and out through King, Snohomish, Pierce, and Kitsap counties — with 100+ projects completed since 2023. Scheduling for a new ADU project usually books 2-4 weeks out for the initial site visit, longer during peak spring and summer construction season. Every project is run directly by Vladislav Volkov, no sales staff and no subcontracted project managers between the homeowner and the person doing the work. Call (206) 591-1096 to check current availability and get a consultation on the calendar.
Ready to start your ADU Construction in White Center?
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What Our White Center Customers Say
Vlad and his team did an amazing job! They built our deck in just 3 days—no issues at all. Communication was easy, and Vlad helped us choose right deck planks. Installation was quick and flawless. Highly recommend!
Really happy with the service! Vlad was easy to communicate with and helped us to find the best garage door opener. The installation was quick and he did a perfect job. A few months later, I had a question and he came by the same day - even on a weekend. That kind of follow-up is rare these days!
Vlad replaced a bathroom exhaust fan and gave me a reasonable quote up front with no hidden fees. While replacing the fan, he discovered a plumbing vent issue causing mold. He fixed the pipe and treated the mold at a reasonable cost. I really appreciate his honesty!
Outstanding work done by Vlad and team for our home cabinet/living room interior work. Very professional and reasonable charges. Love the service.
We hired TopVolk for a full kitchen remodel and couldn't be happier. From the initial consultation to final walkthrough, Vlad was professional and attentive to every detail. The result exceeded our expectations!
Excellent bathroom renovation! Vlad completed the project on time and on budget. His attention to detail and craftsmanship is outstanding. We'll definitely hire him again for future projects.