Most North Shore basement projects fall between $55,000 and $175,000 depending on size, finish level, and whether you add a bathroom or suite. An essential finish runs $55K to $95K, a full living suite with a bathroom and wet bar runs $95K to $175K, and a luxury lower level with a theater, wine room, and custom built-ins runs $175K to $350K and up. Common add-ons: egress windows $6K to $12K each, a basement bathroom with an ejector pump $12K to $25K, and underpinning to raise ceiling height $50K to $150K. Timeline is usually 6 to 12 weeks of construction, plus 3 to 6 weeks for your village building permit.
Every North Shore home is different. We design each lower level around how your family actually wants to use the space.
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Most PopularOpen lounge, home theater, and game space with built-in seating, surround sound wiring, and warm lighting designed for everyday family use.
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Adds ValueA complete lower-level apartment with a bedroom, code-compliant egress, a full bathroom, and an optional kitchenette for guests or multigenerational living.
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Durable rubber or vinyl flooring, mirrored walls, proper ventilation, and reinforced structure for equipment, plus an optional sauna or steam room.
LuxuryEntertaining-ready wet bar with custom cabinetry, sink and beverage fridges, plus a temperature-controlled wine room for serious collections.
A full or half bath below grade, built with a sewage ejector pit and pump so the new bathroom drains properly even below the main sewer line.
Quiet, well-lit work zones, kids playrooms, or multi-use flex rooms with sound insulation, ample circuits, and finishes that feel like the rest of the home.
A finished basement is only as good as the work you cannot see. On the North Shore, near the lake and in century-old housing stock, here is what we address on every project before the finishing begins.
North Shore lots near Lake Michigan often have a high water table and heavy seasonal groundwater. We install interior drain tile, a sump pit with a battery backup pump, dimple board, and vapor barriers so the space stays dry through spring thaw and summer storms. Add: $6K to $18K.
Any basement bedroom requires a code-compliant egress window and window well for emergency exit. On masonry foundations this means cutting the foundation wall, excavating the well, and waterproofing the opening. We engineer and permit this through your village. Add: $6K to $12K per opening.
Older Evanston and Wilmette homes often have basements under 7 feet, below the minimum for habitable space. We gain height with underpinning or bench footing, which lowers the floor safely below the existing footings. This is the single biggest cost driver. Add: $50K to $150K.
Northern Illinois sits in a high-radon zone, and finishing a basement can raise indoor levels. We test, and when needed install a sub-slab depressurization system that vents radon safely above the roofline before we close up the floor. Add: $1.5K to $3.5K.
Century-old North Shore homes can sit on rubble or stone foundations that weep and shed mortar. Before finishing we tuckpoint, parge, and seal the walls, and address any settlement, so the new framing is not fighting a failing foundation. Add: $3K to $15K.
A basement bathroom, wet bar, or kitchenette usually sits below the main sewer line, so gravity drainage does not work. We install a sealed ejector pit and pump that lifts waste up to the sewer, sized and vented to code. Add: $3.5K to $8K.
Transparent pricing with no surprises. We quote the final number upfront after design and a site assessment.
Open finished lower level with rec space, flooring, lighting, and a half bath. Waterproofing and radon handled first.
Multi-zone lower level with a full bathroom, wet bar, and a bedroom or office with code-compliant egress.
No-compromise build with a home theater, wine room, gym or sauna, custom millwork, and underpinning for full ceiling height.
Drag the slider to see the difference. Every project includes waterproofing, radon control, and code work, not just framing and paint.
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Interior drain tile and sump installed, then framed into an open theater and lounge with built-in seating.
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Added an egress bedroom, a full bath on an ejector pump, and a kitchenette for multigenerational living.
Underpinned for full height, then finished with a custom wet bar, wine room, and lounge.
Since 2013, Assembly Squad has completed 500+ renovations across Chicago and the North Shore, from finished family rec rooms in Wilmette to full luxury lower levels in Winnetka and Lake Forest. See a recent Winnetka finished basement, or explore our whole-home North Shore renovations. We do not hand the job to roving subcontractor crews. Our licensed carpenters, plumbers, electricians, and waterproofing trades are the same team on every project.
Our design studio at 2315 N Southport Ave in Lincoln Park is an easy drive from the North Shore via the Edens Expressway or Sheridan Road. Visit to compare flooring, bar and built-in cabinetry, and fixtures in person, see full-size displays, and meet your design team. Our cabinets and built-ins are manufactured in Illinois with 4 to 6 week lead times, not 12 to 16 weeks from offshore.
"Our Winnetka basement flooded twice before we called Assembly Squad. They installed interior drain tile and a battery backup sump, then built us a theater, wet bar, and guest bath. Two springs later it is bone dry and it is the most-used room in the house. They handled the village permits start to finish."
"We have a 1920s Evanston home with a low, damp basement we never used. Three contractors said it could not be a real living space. Assembly Squad underpinned for ceiling height, added a code egress bedroom, and finished a full in-law suite for my mother. They understood the old foundation and the Evanston permit process completely."
Answers to the questions North Shore homeowners ask before finishing a basement.
Beyond basements, Assembly Squad handles every part of your North Shore home.
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Visit our Lincoln Park showroom or schedule a free in-home consultation. Get a fixed-price proposal with no surprises, just transparent pricing.
Lincoln Park Showroom: 2315 N Southport Ave · Serving all North Shore villages