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Bellevue & the Eastside · Design-build basement contractor
From a basic finish to a guest suite or home theater, we check for moisture first, design your basement in 3D, pull the permit and build it with our own crew, for one fixed price.
In-house crews · Licensed, bonded & insured in WA · Permits handled for you
Basement remodel at a glance
Typical cost
$30k – $140k
Build time
4–6 weeks, basic finish
Permit
Needed for most jobs
Design
3D before you sign
Licensed
Bonded & insured in WA
In-house
Crews for the core trades
3D design
See it before we build it
Permits
Filed and managed by us
The short answer
A basement remodel on the Eastside usually costs $30,000 to $140,000. A basic finish with framing, drywall, flooring and lighting runs $30k–$55k, a finish with a new bathroom $55k–$95k, and an in-law suite with a bedroom, bath and egress window $75k–$140k. A basic finish takes about 4 to 6 weeks to build. Most basement projects need a permit for egress windows, new circuits or plumbing, and habitable rooms need about 7 feet of ceiling height.
Reviewed by John, project lead · Prices from our 2026 Seattle-metro basement cost guide · Updated October 2026
Basement services
Every project starts with a moisture check, because a dry basement is the only kind worth finishing.
Framing, insulation, drywall, flooring and lighting that turn bare concrete into living space.
$30k – $55k
4–6 week build
Basement finishing →
A full or three-quarter bath added below grade, with the drain and pumping worked out first.
$55k – $95k
With full finish
Basement bathrooms →
A bedroom, bathroom and egress window, or a fully separate basement ADU with its own entrance.
$75k – $140k
Permit required
Basement ADUs →
Sound-insulated walls, tiered seating, projector or big-screen wiring and dimmable lighting.
$35k – $70k
Wired for your system
Home theaters →
Code-compliant escape windows with excavation, window well and ladder, required for any basement bedroom.
$8k – $18k
Per window
Egress windows →
Interior French drains, sump pumps and vapor barriers, done before any finishes go in.
$10k – $25k
Done first
Waterproofing →
Basement remodeling on the Eastside
One team handles the whole job: a moisture check, 3D design, permits, framing, insulation, electrical and plumbing rough-in, drywall, flooring, lighting, trim, and the final walkthrough that checks egress windows, smoke detectors and emergency lighting. You get one fixed price and one project lead from the first visit to the final inspection.
Basement remodels fail when moisture is ignored. We test for it first and, if groundwater is a problem, add an interior French drain and sump pump before any framing goes up. A finished bedroom also needs a code-compliant egress window, so be wary of any bid that leaves one out.
When the designer and the builder are the same company, the drawings are priced as they're drawn. You never pay for a design you can't afford to build, and change orders drop because the crew helped plan the job.
✓
Moisture check before design
✓
3D render of your new basement
✓
Egress windows for every bedroom
✓
Permits filed and inspections handled
✓
In-house crews, one project lead
Code and permits
Basic finish · 4–6 wk build
Full or 3/4 basement bath
In-law or guest suite
Home theater and media room
Wet bar and game room
Home gym or office
Egress windows for bedrooms
French drain and sump pump
How it works
01
First visit
We visit, measure, check ceiling height and look for signs of water before anything else.
02
Design
We lay out rooms around beams, ducts and the stairs, show it to you in 3D and lock in a fixed price.
03
Permit
We file the permit and, if needed, install the drain and sump pump before framing starts.
04
Build
Framing, rough-in, inspections, insulation, drywall, flooring and trim. A basic finish takes about 4 to 6 weeks.
05
Final
We walk the final inspection, checking egress windows, smoke detectors and lighting, then go through the punch list with you.
Typical projects
Guest suite
A guest bedroom with a code-compliant egress window, a closet and a new bathroom down the hall.
$75k – $140k
Permit required
Rec room
An open rec room with a wet bar, open shelving and space for a pool table, plus a powder room.
$55k – $95k
Finish + bath
Basic finish
Bare concrete finished with rubber flooring, a mirror wall, insulated walls and a storage room for seasonal gear.
$30k – $55k
4–6 weeks
Reviews
Real Google reviews from homeowners we've built for across Bellevue and the Eastside.
FAQ
Straight answers on cost, permits, egress and moisture. Ask us anything else at the free consult.
How much does it cost to finish a basement in Bellevue?
A basic finish runs $30,000–$55,000, a finish with a new bathroom $55,000–$95,000, and an in-law suite $75,000–$140,000. Waterproofing adds $10,000–$25,000 if the basement needs it.
How long does a basement remodel take?
A basic finish takes about 4 to 6 weeks of construction. A bathroom, suite or waterproofing adds time, and permit review comes before the build. You get a full schedule with your fixed price.
Do I need a permit to finish my basement?
In nearly all cases, yes. Egress windows, new electrical circuits and plumbing all need permits in Bellevue and the rest of the Eastside. We file them and handle the inspections.
Does a basement bedroom need an egress window?
Yes. A basement room can't legally be used or sold as a bedroom without a code-compliant egress window. Each one costs $8,000–$18,000, including excavation and the window well.
How tall does my basement ceiling need to be?
Habitable rooms need about 7 feet of ceiling height, with limited exceptions for beams and ductwork. We measure it at the first visit.
Can you finish a damp basement?
Usually, yes, once the moisture is fixed. If groundwater is the problem, we install an interior French drain and sump pump first, which typically costs $10,000–$25,000.
Is finishing a basement worth it?
Per Remodeling magazine's Cost vs. Value data, Seattle-area basement conversions typically return 65–75% at resale. With Eastside homes at $1.2 to $2.5 million, finished square footage adds real value.
Start your basement remodel
Tell us about your basement. We'll visit, check moisture and ceiling height, talk through layout and budget, then send you a fixed price.
Renovision Design & Build LLC
1400 112th Ave NE, Bellevue, WA 98004
(425) 276-6501 · Mon–Fri 8–5
Basement remodeling near you
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