Renovation Contractor in Oshawa & Durham Region
Home theatres. Wellness gyms. Custom wet bars. Golf simulators. We turn raw concrete into the space your family actually uses.
Back to Basement FinishingYour unfinished basement is the most underused space in your home. Most homeowners leave it that way for years — bare concrete, exposed joists, a furnace in the corner. The ones who act on it end up with the house the whole neighbourhood wants to be in.
A standard recreational basement does not carry the same permit complexity as a legal suite — there is no separate entrance or occupancy permit to chase. But the moment you add plumbing, underpinning, or other structural work, permits absolutely apply, and we handle them. Either way, the standard of craft stays the same — Level 4 drywall, engineered flooring, dedicated electrical, and proper ventilation to keep the air fresh and the space livable.
We build three types of recreational basements at Cornerstone. Tell us how you want to use the space and we will build it around that.
Not every recreational basement is the same build. The space you want determines the structure, the electrical, the ventilation, and the finish standard we build to.
$30,000 – $75,000+
Most popular starting point — design around how your family actually uses the space.
$50,000 – $120,000+
Technology should be felt — not seen. Every cable planned at framing not added after drywall.
$40,000 – $100,000+
The 2026 standard has moved well beyond a treadmill and some rubber mats.
Technology should be felt — not seen. We build theatres where the performance is invisible and the experience is total.
Modular panels spanning 163 inches or more. High brightness — no pitch-black room required. Replaces traditional projectors for multi-functional entertainment hubs. Works in any lighting condition.
In-wall and in-ceiling speakers plastered over or hidden behind acoustic fabric. Sound felt not seen. Dolby Atmos spatial audio is the 2026 baseline standard for luxury builds in Durham Region.
Every cable runs inside wall cavities during rough-in. No surface conduit. No afterthought mounting. Planned at framing — not added after drywall. One of the most common mistakes on DIY theatre builds.
Specialized wall treatments prevent vibration transfer through the structure. Recessed lighting maintains clean sightlines. Custom millwork conceals all equipment behind clean architectural lines.
The biggest mistake on home theatre builds is running wire after drywall. We plan every cable run, every speaker location, and every equipment bay before a single sheet of drywall goes up.
The traditional home gym is gone. The 2026 standard is a full wellness sanctuary — gym, sauna, cold plunge, and recovery all in one dedicated zone built to last 20 years.
Radiant heat penetrates muscle tissue at lower more comfortable air temperatures than traditional steam. Installed with dedicated electrical and ventilation. The defining luxury feature of 2026 Durham Region homes.
Installed adjacent to saunas for hot-cold therapy cycles. Requires dedicated drainage and a moisture-proof environment finished in natural stone or large-format tile. Structural waterproofing applied before any finish work begins.
Rubber flooring systems rated for heavy impact. Protects the structural floor, reduces vibration, and handles dropped weights without damage. Installed over a level subfloor — we assess and correct the concrete before any flooring goes down.
Energy Recovery Ventilators exchange stale basement air with filtered outdoor air. Essential for high-intensity training spaces and enclosed sauna rooms. Without an ERV a sealed basement gym becomes unusable within minutes of a hard workout.
Infrared saunas, cold plunge pools, and steam showers all require dedicated electrical, plumbing, and waterproofing planned at rough-in. You cannot add them cleanly after drywall. We plan the full wellness build from day one.
A custom wet bar turns your basement into the destination. Full-service entertainment areas built to the same standard as your main floor kitchen.
Quartz or granite surfaces matching your main floor standard. Full overhang for bar seating. Built-in drainage and backsplash tiled to ceiling. Same stone supplier and finish standard as your kitchen if desired.
Same cabinet line as your kitchen if desired. Full-extension soft-close drawers. Wine storage, glass rack, and undercounter refrigeration integrated into the millwork. Built to last — not flat-pack.
Sink, dishwasher, and ice maker connections roughed in during framing. Exhaust fan vented to exterior. All drain lines to municipal sewer — no grey water shortcuts. Inspected and approved before drywall closes.
A climate-controlled wine room with frameless glass panels turns your collection into a feature. Dedicated cooling unit, custom wood racking, LED accent lighting, and a frameless glass door and wall system. Visible from the entertainment space — not hidden in a corner.
Plumbing, electrical, and ventilation for a wet bar or wine room must be planned before framing closes. Adding a sink or wine cooler after drywall means opening walls. We plan the full entertainment build from day one so nothing gets added as an afterthought.
A properly built golf simulator is one of the most demanding basement projects — structurally, mechanically, and acoustically. Most Durham Region basements need modifications before a simulator can be installed.
Ceiling height below 8 feet triggers underpinning or bench footing — assessed separately at your diagnostic before any other scope is quoted.
Start Your Basement DiagnosticIf your existing basement is below 8 feet — or you want a golf simulator — we assess two structural options before any other work begins. Both require a structural engineer stamp before permit submission.
Before any underpinning or bench footing work begins, drawings must be stamped by a licensed structural engineer and submitted with your building permit application. Cornerstone coordinates the engineer assessment as part of your project diagnostic — you do not make a single call to the city.


All Cornerstone recreational basements are built to Level 4 drywall standard with dedicated electrical, proper ventilation, and engineered flooring throughout.
Three build types. Real numbers. One locked price before we start.
$45 – $110 per sq ft
Open concept layout, pot lights, LVP flooring, Level 4 drywall, and dedicated electrical throughout. Rate varies by finish level.
$65 – $150 per sq ft
Acoustic panels, hidden wiring, tiered seating platform, dedicated HVAC zone, and custom millwork surround. Rate varies by finish level.
$55 – $130 per sq ft
Engineered rubber flooring, ERV ventilation, mirror wall rough-in, dedicated electrical, and Level 4 drywall. Rate varies by finish level.
$15,000 – $30,000
Toilet, vanity, shower or tub, tile, ventilation fan ducted to exterior, and all rough-in plumbing. Level 4 drywall finish standard.
$12,000 – $25,000
Custom stone counters, premium cabinetry, undercounter refrigeration, sink, and full plumbing rough-in. Exhaust fan vented to exterior.
$15,000 – $35,000
Climate-controlled wine room with frameless glass panels, dedicated cooling unit, custom wood racking, and LED accent lighting.
$8,000 – $20,000
Custom cabinetry, shelving, equipment bays, and built-in entertainment units. Designed around your specific equipment and storage needs.
$8,000 – $20,000
Dedicated electrical, ventilation, and cedar or hemlock cabin construction. Sized for 1 to 4 persons. Installed adjacent to cold plunge or wellness zone.
$10,000 – $25,000
Dedicated drainage, moisture-proof environment, natural stone or large-format tile finish, and dedicated plumbing rough-in.
$3,500 – $8,000
Integrated into custom millwork surround. Dedicated electrical circuit. No gas line or venting required. Ambiance and supplemental heat.
$6,000 – $14,000
Direct-vent gas fireplace integrated into millwork surround. Gas line rough-in and exterior venting included. Licensed gas fitter coordinated by Cornerstone.
$35,000 – $80,000+
Structural clearance, acoustic treatment, hidden wiring, and custom millwork enclosure. Ceiling height below 8 feet triggers underpinning — assessed separately.
Select your build type, adjust square footage, choose finish level, and add optional scopes to refine your estimate.
Estimated investment range
$48,000 – $64,000
Ranges reflect Durham Region market pricing as of 2025. Final investment confirmed in your written proposal — price locked before work begins.
Start Your Basement DiagnosticBook your project diagnostic. We walk the basement, confirm ceiling heights, and tell you exactly what the space can support — before a dollar is spent.
Durham Region's trusted renovation contractor. Led by Mike Brock since 2017. We Listen, We Build, We Deliver.