Best ADU Builders in Clark County, WA (2026)

By the JDI Construction teamFacts checked November 2, 2026Rechecked quarterly

JDI Construction wrote this page, and we are one of the companies on it. Every company is scored the same way, on public facts linked below, using the published method. You can change the weights and re-rank the list yourself. Facts checked November 2, 2026.

Quick answer

On our published criteria, JDI Construction scores highest for ADUs in Clark County (82 of 100), followed by Lamont Bros (74), Wolf Industries (70), and Neil Kelly (68). If independent awards matter most to you, look at Lamont Bros; for the deepest review record, Neil Kelly. Change the weights below to rank by what matters to you.

Washington's ADU law (RCW 36.70A.681, from HB 1337) requires cities and counties in urban growth areas to allow two ADUs per lot, with no owner-occupancy rule and impact fees capped at half the main house's. The City of Vancouver allows up to two ADUs of up to 1,000 sq ft each with no parking minimum, and unincorporated Clark County waives 75% of transportation, school and park impact fees for ADUs.

Builders range from custom design-build firms to factory-built modular. Only three of the nine publish ADU prices. We could not verify a Washington contractor registration for Premier ADU Builders as of November 2, 2026, so it is not listed.

Scores at a glance

Seven criteria, 100 points, the same for every company. Hover a score to see the fact behind it. How each criterion is scored.

Company	License /15	Reviews /25	Warranty /15	Local /15	Prices /10	Awards /10	Record /10	Total /100
1JDI Construction	14.5	22.8	15	15	0	5	10	82.3
2Lamont Bros	9	18.1	9	8	10	10	10	74.1
3Wolf Industries	14	20.4	3	15	10	0	8	70.4
4Neil Kelly	15	19	10.5	8	0	5	10	67.5
5Black Cat Design Build	10	18.7	0	15	0	0	10	53.7
6ISEE Construct	7.5	0	0	15	10	0	8	40.5
7My ADU	7	0	0	15	0	0	10	32.0
8Vancouver ADU	8	0	0	15	0	0	5	28.0
9Triangle Bar Group	6.5	0	0	8	0	0	8	22.5

Care more about some things than others? Change the weights

Set a criterion to 0× to ignore it, or 3× to make it count triple. The totals and the order update right here; nothing is sent anywhere.

License and track record1×Client reviews1×Written warranty1×Clark County presence1×Price transparency1×Independent recognition1×Complaint record1×

The list

1JDI Construction 82.3 / 100 · Vancouver, WA (1419 Broadway St)

Best for: Clark County kitchens, baths, ADUs and additions where a local team, a written 5-year warranty and a shorter build matter.

In business: since 2007 (WA contractor registration since May 2007)
License: WA L&I JDICOCN932KZ · OR CCB 176101
Reviews: Google 4.9 from 213 (Vancouver profile; the Portland profile adds 12 at 5.0); Google (Portland) 5.0 from 12; HomeAdvisor 5.0 from 120; Houzz 5.0 from 38; GuildQuality 4.9 from 28
Complaint record: BBB A+, accredited since Jul 2026, 0 complaints in 3 years
Warranty: 5-year written workmanship warranty
Published prices: None published for this project type
Design and services: Free estimate and free 3D design layouts (current offer)
Timeline: Hall bath 3 to 4 weeks, primary bath 6 to 8 weeks of construction
Small jobs: Yes: shower-only and smaller projects
Recognition: Best of Houzz 2022, 2024 and 2026; GuildQuality Guildmaster 2026

Keep in mind: Younger and smaller than the Portland firms here: 28 GuildQuality surveys against hundreds or thousands, no national awards, no showroom.

This is us. Our scores use the same rules as everyone else's. See our warranty and published prices.

2Lamont Bros. Design & Construction 74.1 / 100 · West Linn, OR (showroom, 18675 Willamette Dr) · Website

Best for: Larger, design-heavy projects ($75,000 and up), mostly on the Oregon side, with a fixed-price contract.

In business: since 2008 (founded 2008 in West Linn)
License: WA L&I LAMONBL820RR · OR CCB 184500
Reviews: Houzz 4.8 from 53; Google 4.7 from 105 (as shown on Birdeye); BBB 4.2 from 5
Complaint record: BBB A+, accredited since Dec 2025, 0 complaints in 3 years
Warranty: 3-year limited workmanship warranty; issues reported within 2 weeks
Published prices: ADUs "start around $150,000" (source)
Design and services: Design retainer "typically a few thousand dollars"; fixed-price contract with no allowances
Timeline: A couple of months of design; about a month to build a small bath
Small jobs: No: does not take single-trade jobs
Recognition: Two 2026 NARI National Remodeler of the Year awards; Best of Houzz Service 2016 to 2025

Keep in mind: Showroom in West Linn, about 30 to 40 minutes from Vancouver; no single-trade or small jobs.

3Wolf Industries 70.4 / 100 · Battle Ground, WA (factory, 607 SE Eaton Blvd) · Website

Best for: A price-transparent, factory-built detached ADU from a Clark County manufacturer.

In business: since 2008 (WA registration since January 2008)
License: WA L&I WOLFIII921BD
Reviews: Google 4.9 from 120 (as shown on its own website)
Complaint record: BBB A+, not accredited, complaint count not shown
Warranty: Written one-year warranty
Published prices: Modular units from $85,500 (432 sq ft) to $167,500 (984 sq ft) for the home; $121,000 to $217,400 with delivery and setup; site work, permits and taxes extra (source)
Design and services: Factory-built modular models; coordinates design, permits, site work and installation
Timeline: Typical permit review 4 to 6 weeks (per its website)
Small jobs: ADUs and modular homes only
Recognition: None found

Keep in mind: Modular models rather than custom design; one-year warranty; site work priced separately.

4Neil Kelly 67.5 / 100 · Portland, OR (804 N Alberta St); also Seattle and Bend · Website

Best for: Large, high-budget remodels by owners who want the region's longest track record and a structured, paid design phase.

In business: since 1947 (founded 1947; Oregon CCB license since 1972)
License: WA L&I NEILKCI187O2 · OR CCB 1663
Reviews: GuildQuality 4.6 from 2,381; Houzz 4.4 from 29
Complaint record: BBB A+, accredited since 1976, 0 complaints in 3 years
Warranty: 5 years on work by its own carpenters, 2 years on subcontracted work
Published prices: None published for this project type
Design and services: Free home visit; design retainer from $2,000, then 5 to 10% of the projected cost (both credited to the project)
Timeline: 30 to 44 weeks from first design meeting to finish (design 12 to 16, planning 6 to 8, construction 12 to 20)
Small jobs: Handyman service at $125/hour, Portland and Bend
Recognition: Best of Houzz 2013 to 2017, 2020, 2022 to 2026; GuildQuality Guildmaster 2025 and 2026; Certified B Corp since 2013

Keep in mind: Serves Clark County from North Portland; a typical project runs 30 to 44 weeks.

5Black Cat Design Build 53.7 / 100 · Vancouver, WA · Website

Best for: Design-led remodels, additions and ADUs where the owner-designer is directly involved.

In business: since 2016 (BBB business start date)
License: WA L&I BLACKCD847MJ
Reviews: Google 5.0 from 13 (as shown in a widget on its own website)
Complaint record: BBB A+, not accredited, 0 complaints in 3 years
Warranty: No written warranty terms published
Published prices: None published for this project type
Design and services: Owner Chris Miller is an NCIDQ-certified designer; free consultation, line-item budgets
Timeline: Not published
Small jobs: Not stated
Recognition: None found

Keep in mind: Few public reviews we could verify; no published prices, timelines or warranty terms.

6ISEE Construct 40.5 / 100 · Battle Ground, WA · Website

Best for: A local general contractor for any ADU type, with published cost and time ranges.

In business: since 2021 (WA registration since October 2021)
License: WA L&I ISEECCL792QQ
Reviews:
Complaint record: BBB A+, accredited, complaint count not shown
Warranty: No written warranty terms published
Published prices: ADUs $120,000 to $350,000 (source)
Design and services: Manages the permit application; detached, attached, garage and above-garage ADUs
Timeline: 6 to 14 months from contract to final inspection
Small jobs: General contractor; ADU types of every kind
Recognition: None found

Keep in mind: Newer firm; no public review counts we could open; no published warranty terms.

7My ADU 32.0 / 100 · Vancouver, WA (10110 NE 13th Ave) · Website

Best for: Homeowners who want a pre-designed, site-built ADU model with permitting handled for them.

In business: since 2019 (per its website; WA registration since 2022)
License: WA L&I MYADUAL780DD · OR CCB 242640
Reviews:
Complaint record: BBB A+, accredited since Sep 2022, 0 complaints in 3 years
Warranty: No written warranty terms published
Published prices: None published for this project type
Design and services: About 18 pre-designed models (192 to 988 sq ft); design, permitting and turnkey packages; permitting handled in-house
Timeline: Homepage says "in 6 to 9 months" and "as little as 12 weeks"
Small jobs: ADUs only
Recognition: None found

Keep in mind: No public review counts we could open; no published dollar prices or warranty terms.

8Vancouver ADU (Hammer Falls Construction) 28.0 / 100 · Vancouver, WA · Website

Best for: Custom, higher-end ADUs (the firm calls its work luxury).

In business: since 2020 (WA registration since March 2020)
License: WA L&I HAMMEFC803DW
Reviews:
Complaint record: No BBB rating found
Warranty: No written warranty terms published
Published prices: None published for this project type
Design and services: Detached, garage-conversion and attached ADUs; permit and zoning assistance
Timeline: Not published
Small jobs: Not stated
Recognition: None found

Keep in mind: No public reviews or BBB profile found; no published prices, timelines or warranty terms.

9Triangle Bar Group 22.5 / 100 · Portland, OR · Website

Best for: Architect-led custom ADU design on tight or historic lots.

In business: since 2023 (WA registration since April 2023)
License: WA L&I TRIANBG771DC · OR CCB 240616
Reviews:
Complaint record: BBB A+, not accredited, complaint count not shown
Warranty: No written warranty terms published
Published prices: None published for this project type
Design and services: Design-build with in-house design; detached, cottage and garage-conversion ADUs
Timeline: Not published
Small jobs: Not stated
Recognition: None found

Keep in mind: Portland-based; one Vancouver ADU shown; no public reviews, prices or warranty terms found.

How to choose between them

Custom or model? Pre-designed and modular models are faster to price; custom design fits odd lots and matching an older house.
Ask what the price includes. Site work, utility connections, permits and impact fees are often extra and can add tens of thousands.
Permits. Ask who prepares and submits the permit set, and who answers plan-review comments.

Common questions

What does an ADU cost in Clark County?

Of the builders here, three publish prices: Wolf Industries' modular units run $121,000 to $217,400 delivered and set (site work extra), ISEE Construct quotes $120,000 to $350,000, and Lamont Bros says ADUs start around $150,000.

Why does JDI score 0 for ADU prices?

We have not published an ADU price range yet, so by our own rules we get 0 on that criterion until we do.

Did anyone pay to be listed?

No. No company paid to be listed or ranked.

Sources (checked November 2, 2026)

Ratings, prices and licenses change. We recheck every quarter. If you represent a company on this page and something is out of date, email info@jdinw.co with the source and we will correct it.