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What a Portland basement remodel costs in 2026.
Real 2026 Portland pricing for standard finishes, full finished basements, and basement ADUs, with a working calculator and itemized budgets from a 5.0-rated design-build firm.
How much does a basement remodel cost in Portland in 2026?
Finishing a basement in Portland runs $70K to $490K+ in 2026, or about $120 to $400 per square foot. Most full finished basements, a family room plus a full bath and a bedroom or office, land between $150K and $200K. A basic open finish without a bathroom starts around $70K, while a legal basement ADU with a kitchen and separate entrance runs $350K to $490K and up. The five ranges at right reflect real WCG basement projects across the Portland metro over the last twelve months.
Cost CalculatorA finished basement is the most affordable square footage you can add to a Portland home, but only if the water is handled first. We price every basement from the foundation up: moisture, then structure, then the finishes you actually live in.
Build your full 2026 basement budget.
Ten real-world levers tuned to Portland basement data. Choose your size, finish tier, and scope, and the live estimate updates with every selection. Your choices carry into the consultation form.
This is an estimate built on 2026 Portland data. For the true cost of your basement, schedule a free in-home estimate.
Contributing factors
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Estimate range based on 2026 Portland project data. Final pricing requires an in-home consultation and itemized estimate, delivered within one business day.
Every line on a WCG basement estimate ties back to one of these six factors. Some you choose. Some the foundation tells us.
Square footage & ceiling height
More square footage means more of every line. Low basements may need the floor lowered (underpinning) to reach code headroom, one of the largest single costs a basement can carry.
Moisture & waterproofing
Portland's rain and water table come first. Interior drainage, a sump pump, and a vapor barrier get solved before any framing, or you trap water behind brand-new walls.
Adding a bathroom
Below-grade baths drain under the sewer line and need a sewage ejector pump. It is the single biggest cost jump in most basements, and the highest-value one.
Egress & code
A legal bedroom needs an egress window cut into the foundation. A basement ADU adds a full code path of its own: ceiling height, fire separation, and a separate entrance.
Finish grade & built-ins
Wet bars, home theaters, a gym, custom millwork, and flooring grade. This is the range you control most, and where a basement turns into the favorite room in the house.
One design-build team
Design-build means one contract for design and construction. You get an itemized estimate before demolition, fewer change orders mid-project, and a price that holds.
Pick a tier. The number follows.
A Portland basement of the same footprint can land at $120K, $178K, or $300K+ depending on whether it gets a bathroom, a kitchen, and how it is finished. The choice is not better or worse. It is how you plan to use the space.
- Open rec or family room
- Insulation, framing, and drywall
- Luxury vinyl plank flooring
- Recessed lighting throughout
- A half bath
- Vapor barrier and minor drainage
- Paint, trim, and doors
- Family room plus a bedroom or office
- A full bath with an ejector pump
- Egress window for a legal bedroom
- Engineered or upgraded flooring
- Interior drainage and a sump pump
- Layered lighting and added circuits
- Built-in shelving or a media wall
- Mid-grade finishes throughout
- A legal basement ADU or premium suite
- Full kitchen or large wet bar
- Full bath, sometimes two
- Bedroom, egress, and a separate entrance
- Full waterproofing with a backup sump
- Home theater, gym, or wine room
- Custom millwork and built-ins
- High-end flooring and lighting
What a Portland basement actually costs.
Three tiers cover most Portland basements in 2026. Where you land depends on size, whether you add a bathroom or kitchen, and the finish grade. The table maps each tier to what it includes and the range it typically runs.
| Tier | What it includes | 2026 Range |
|---|---|---|
| Standard Finish Good | Open rec room, half bath, luxury vinyl plank flooring, recessed lighting, vapor barrier and minor drainage. No major plumbing or moved walls. About $120 to $150 per square foot. | $108K to $150K |
| Full Finished Better | Family room, a full bath with an ejector pump, a bedroom or office, egress window, interior drainage with a sump pump, and built-ins. About $150 to $200 per square foot. | $150K to $200K |
| Premium / ADU Best | A kitchen or large wet bar, full bath, bedroom, a separate entrance, full waterproofing, and custom millwork. A legal basement ADU lives here. About $200 to $350+ per square foot. | $200K to $350K+ |
Sample ranges shown for a 1,000 sq ft Portland basement. Ceiling height, moisture conditions, and finish level move the final number. Every estimate is itemized before demolition.
The finishes that move a basement number.
Once the space is dry and framed, four choices drive most of the spread between a $120K basement and a $300K one. Here is where the budget actually goes.
Flooring built for below grade.
Below grade, flooring has to handle humidity and the occasional cold slab. Luxury vinyl plank is the Portland default for its waterproof core. Engineered wood and porcelain tile step it up, and polished concrete is a modern, moisture-proof option.
Luxury vinyl plank runs about $6 to $9 per square foot installed. Engineered wood and tile reach $12 to $18 once you add underlayment and a moisture barrier over the slab.
- Installed
- $6 to $18 per sq ft
- Premium
- Tile & polished concrete over base
Egress windows and daylight.
An egress window is required for any legal basement bedroom, and it changes how the whole basement feels. Cutting and shoring the foundation is the real cost; the payoff is light, code-compliant safety, and a room that legally counts.
One egress window with a well runs $4K to $9K installed in Portland. A second well or an oversized opening adds to that, as does any structural shoring the foundation needs.
- Per window
- $4K to $9K installed
- Premium
- Two or more wells over base
A full basement bath.
The highest-value square footage in the basement. Because the fixtures sit below the main sewer line, a basement bath needs an ejector or up-flush pump, which is most of the cost difference from an upstairs bath. A tiled wet room is the premium version.
A half bath runs less; a full bath with a tiled shower and an ejector pump lands at $15K to $35K. It is one of the few additions that pays for itself at resale.
- Full bath
- $15K to $35K
- Premium
- Tiled wet room over base
Built-ins: theater, gym, wine.
This is where a basement becomes the favorite room in the house. A media wall, a home gym floor, a wet bar, or a glassed wine room. Custom millwork is the line you control most, and the one guests remember.
Shelving and a simple media wall start around $5K. A full custom built-in package with a wet bar or wine room reaches $30K and up with cabinetry, glass, and cooling.
- Built-ins
- $5K to $30K+
- Premium
- Full custom millwork over base
See Portland basements we have transformed.
Recent Portland basement projects, from Lake Oswego media rooms to Hawthorne basement ADUs with private entrances. Real spaces, real budgets, built by one accountable team.
See Full GalleryThree 2026 basements, itemized.
Below are the actual itemized totals from three WCG basements completed within the past twelve months in Portland. Names changed; numbers and scope real.
Schedule Free Consultation
Open rec room with a half bath.
- Design + permits$11,000
- Moisture prep + vapor barrier$13,000
- Framing, insulation, drywall$32,000
- Half bath$14,000
- Flooring (LVP)$18,000
- Electrical + lighting$16,000
- Paint, trim, doors$11,000
- Contingency$7,000
Family room, full bath, and office.
- Design + permits$16,000
- Waterproofing + vapor barrier$18,000
- Framing, insulation, drywall$30,000
- Full bath (with ejector pump)$34,000
- Flooring throughout$20,000
- Electrical + lighting + HVAC$24,000
- Trim, paint, doors, built-ins$20,000
- Contingency$16,000
Legal apartment, kitchen, separate entrance.
- Design + permits + engineering$38,000
- Waterproofing + drainage + sump$34,000
- Framing + insulation + drywall$48,000
- Full kitchen$62,000
- Full bath + ejector plumbing$52,000
- Bedroom, egress + separate entrance$46,000
- Flooring, trim, paint, doors$44,000
- Electrical, HVAC + lighting$52,000
- Permits + contingency$44,000
Line items that most homeowners miss.
The visible scope is flooring, drywall, and a bathroom. The complete 2026 budget covers eight more line items that catch homeowners off guard the first time they price a basement. We itemize all of them in the estimate.
Schedule Free Consultation- $5K to $35K
Moisture testing and waterproofing
Portland's water table and rain come first. Interior drainage, a sump, and a vapor barrier get solved before any framing goes in.
- $2K to $6K
Sewage ejector pump
A below-grade bath drains below the sewer line and needs a pump to lift waste up to the main. Required for any basement bathroom.
- $4K to $9K
Egress window and well
Required for any legal basement bedroom. Cutting and shoring the foundation is the real cost, not the window itself.
- $2K to $10K
Permits and inspections
Building, electrical, plumbing, and mechanical permits across Multnomah, Washington, or Clackamas county. A basement ADU adds scope.
- $15K to $60K
Ceiling height and underpinning
Low basements may need the floor lowered to reach code headroom. One of the largest single costs a basement can carry.
- $1.5K to $4K
Radon mitigation
Common in Portland-area basements. A sub-slab depressurization system vents radon safely above the roofline.
- $3K to $12K
HVAC extension and dehumidification
Conditioning and dehumidifying the new below-grade living space, often with a mini-split or an extended trunk line.
- 8 to 12%
Project contingency
8 to 12 percent of total scope. For hidden moisture, foundation cracks, and old wiring found behind basement walls.
Design-build experience in Portland
Portland-area homes transformed since 2008
Across Google, Houzz & Yelp
On every basement we finish
Portland homeowners on their basements.
Our basement was a damp storage pit for fifteen years. Woodland solved the water first, then built us a family room, a full bath, and a guest suite. They handed us an itemized number before demolition and the final invoice matched it almost to the dollar.
They turned our basement into a legal ADU with its own entrance. It rents out now and paid for a big chunk of the project. The permitting was handled start to finish.
A home theater, a gym, and a wet bar in a basement we never used. The built-in millwork is the part everyone comments on. Five stars and we would do it again.
Finishing a basement in Portland costs $70,000 to $490,000 in 2026, or about $120 to $400 per square foot. Most full finished basements, with a family room, a full bath, and a bedroom or office, land between $150,000 and $200,000. A basic open finish without a bathroom starts near $70,000, while a legal basement ADU with a kitchen and a separate entrance runs $350,000 and up. Square footage, a bathroom, and waterproofing drive most of the spread.
Adding a bathroom is usually the single biggest cost jump, because a below-grade bath drains below the sewer line and needs a sewage ejector pump, which can add $15,000 to $35,000. A full basement kitchen for an ADU, structural waterproofing, and lowering the floor for ceiling height are the next largest drivers.
In almost every Portland basement, yes. Our rainfall and high water table mean moisture has to be controlled before any framing goes in, or you trap water behind new walls. Depending on conditions, that ranges from a vapor barrier and minor drainage to a full interior drainage system with a sump pump, roughly $5,000 to $35,000. We test and solve moisture first, every time.
Yes. A basement bathroom runs about $15,000 to $35,000 in 2026 because the fixtures sit below the main sewer line and need a sewage ejector or up-flush pump to move waste up to the sewer. A half bath is less; a full bath with a tiled shower and an ejector pump is at the higher end. It is one of the highest-value additions a basement can get.
Most Portland basement remodels take 8 to 16 weeks of construction after a 3 to 5 week design and selection phase. A standard open finish can wrap in 8 to 10 weeks. A full finished basement with a bath runs 12 to 14 weeks, and a legal basement ADU with a kitchen and a separate entrance can take 5 to 7 months once permits are included.
Yes. A finished basement typically returns 70 to 75 percent of its cost at resale and adds usable square footage at a lower cost per foot than an addition. A legal basement ADU adds the most value in Portland because it can generate rental income and appeals to buyers looking for a multi-generational or income option.
Yes. Finishing a basement requires building permits, and any new electrical, plumbing, or mechanical work pulls its own trade permits. A legal bedroom needs an egress window, and a basement ADU has a full code path of its own. As your design-build contractor, we pull every permit and schedule every inspection so the finished space is legal and documented.
Pricing for the Portland metro.
The estimates above reflect 2026 labor and material costs across the Portland metro. We design and build throughout these communities. Find your city for local project examples.
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