Home Spa and Sauna Builder in Denver: Saunas, Steam Rooms, and Cold Plunges

Gribbons Group Corp builds home saunas, steam rooms, and cold plunges across the Denver metro, with the waterproofing, ventilation, electrical, and drainage each one needs.

A home spa puts heat, water, and steam inside a house that was never designed for them. Done well, it’s the room you use every day. Done poorly, it’s hidden moisture damage, a tripped breaker, and a smell you can’t find. As a licensed & insured general contractor, we plan the parts behind the walls first.

Planning a home spa? Call (720) 223-9003 or request a free estimate.

Home Saunas

A sauna is a dry-heat room, typically lined in wood, heated by an electric heater or infrared panels. We build custom saunas into basements, bathrooms, and spare rooms, or build in a prefabricated sauna kit where that fits better.

• Traditional vs. infrared. Traditional saunas heat the air with an electric heater and rocks, and many let you ladle water for bursts of steam. Infrared saunas use panels that warm you more directly at lower air temperatures. The choice changes the heater, electrical, and construction details.
• Insulation and vapor control. Walls and ceiling are insulated, and a traditional sauna typically gets a foil vapor barrier behind the wood lining so moisture from the hot room doesn’t drive into the framing.
• Interior lining and benches. Softwoods chosen for heat and moisture, with hidden fasteners and benches at heights that put you in the heat without hitting the ceiling.
• Heater clearances. Heaters have listed clearances to walls, benches, and ceiling. We follow the manufacturer’s installation instructions exactly, including guard rails around the heater.
• Ventilation. A sauna needs fresh air in and stale air out, placed where the heater manufacturer calls for it. The surrounding room also needs to handle the heat and moisture that escape when the door opens.
• The door. Sauna doors are typically glass or wood, open outward, and have no lock, following common manufacturer guidance.

Steam Rooms and Steam Showers

A steam room is the most demanding wet room in a house. It fills with hot vapor that’s looking for any way into the walls, so the whole enclosure has to be built as a sealed, waterproof box.

• Vapor-tight waterproofing on every surface: walls, floor, bench, and ceiling. A regular shower membrane isn’t always enough for continuous steam, so we use a system rated for steam rooms and follow its details at every seam, corner, and penetration.
• Sloped ceiling. A slight slope keeps condensation running down the walls instead of dripping on you.
• A vapor-tight door and enclosure that runs to the ceiling, since steam rises and escapes over a partial wall.
• The steam generator lives outside the steam room, in a vanity, closet, or nearby mechanical space, within the distance the manufacturer allows. It needs a water supply, a drain or drain pan per the instructions, and a dedicated circuit.
• Tile and seating. Tile set on the waterproofing, a sloped bench so water drains off, and a steam head placed away from where you sit.
• Controls inside and outside the room, plus lighting rated for wet locations.

A steam shower combines a regular shower with a steam generator in the same enclosure. It’s a common upgrade in a bathroom remodel, and it gets the same vapor-tight construction as a dedicated steam room.

Cold Plunges

Cold plunges range from freestanding tubs with a plug-in chiller to built-in, tiled plunge pools with filtration. What they have in common is water weight, electrical, and drainage.

• Structure. Water weighs about 8.3 pounds per gallon, so a filled plunge is a heavy concentrated load. On a slab it’s usually simple. On a framed floor, we check whether the structure can carry it and reinforce if needed.
• Electrical. Chillers and filtration pumps need the circuit the manufacturer specifies, plus the ground-fault protection the electrical code and manufacturer require for equipment near water.
• Drainage. You’ll need to drain and refill the plunge. A nearby floor drain, or a plan for pumping it out, saves you from hauling water.
• Equipment placement. Chillers make noise and reject heat, so they need airflow and a location that doesn’t bother the rest of the house.
• Floors and surroundings that can get wet, with slip-resistant surfaces.

Wet-Room Waterproofing

Many home spas are built as a wet room: sauna, shower, and plunge in one space, with a floor that can take water anywhere. That only works if the whole room is waterproofed as a system:

• A continuous waterproofing membrane on the floor, turned up the walls, and fully bonded to every drain.
• Floors sloped to drains, whether that’s a center drain, linear drains along a wall, or a curbless entry.
• Wall waterproofing wherever water will hit, not just inside the shower area.
• Materials that tolerate moisture behind the tile: cement board or foam board rather than standard drywall in wet zones.
• Flood testing the membrane before tile goes on, so problems show up while they’re still easy to fix.

In a basement, waterproofing also means dealing with the slab and foundation walls. If there’s any history of water in the basement, we fix the source before building a spa against it.

Ventilation and Moisture Control

Every spa feature adds moisture to the house. Steam, shower spray, a hot sauna room, and an open plunge all put water into the air, and that moisture has to go somewhere other than your walls and ceiling.

• Exhaust fans sized for the room and ducted outdoors, never into an attic or ceiling cavity.
• Controls like humidity sensors or timers so the fan keeps running after you’re done.
• Makeup air so the exhaust can actually work, especially in tight basements.
• HVAC coordination so the spa area stays comfortable and the rest of the house isn’t pulling in humid air.
• Sauna ventilation per the heater manufacturer, separate from the room’s exhaust.

Electrical Load

Home spa equipment draws real power. A traditional sauna heater, a steam generator, and a cold plunge chiller can each need a dedicated circuit, and electric sauna heaters and steam generators commonly run on 240 volts. Add heated floors and lighting, and the total can be more than an existing panel has room for.

During the walkthrough we look at your electrical panel’s capacity and the equipment you’re considering. If the panel can handle it, we plan circuits from the manufacturers’ specifications. If it can’t, we plan for a subpanel or talk through a service upgrade before design goes further, so you’re not choosing equipment the house can’t power.

Drainage

Steam rooms, showers, wet-room floors, and plunges all need somewhere for water to go. In a basement, that can be the hardest part: fixtures below the level of your main sewer line may need an ejector pump, and adding a floor drain means cutting the slab and tying into the existing drain lines. We check drain depth and layout on the first visit and plan drainage before anything else is designed.

Permits and Planning Notes

A home spa usually involves plumbing, electrical, mechanical, and sometimes structural work, and that typically means a building permit. Requirements depend on your city or county. We confirm with your building department before design and handle the drawings, application, and inspections.

Many home spas end up in the basement, where there’s room and privacy. If you’re finishing the rest of the space, see what you can put in a finished basement.

How a Home Spa Project Works

1. Walkthrough. We look at the space, electrical panel, drain depth, ventilation routes, and floor structure.
2. Design. Sauna, steam, plunge, showers, and layout, with equipment chosen to fit the house.
3. Written scope and estimate. Waterproofing, ventilation, electrical, drainage, equipment, and finishes spelled out.
4. Permits. Drawings, application, and inspections.
5. Build. Rough plumbing, electrical, and ventilation, inspections, waterproofing and flood testing, then tile, lining, equipment, and finishes.
6. Startup and walkthrough. We run every system and show you how to use and maintain it.

More on how we work is on our process page.

Licensed & Insured

Gribbons Group Corp is licensed & insured and holds these contractor licenses: Douglas County #A260170, Jefferson County Class B #1028872, City of Littleton #AEC002126, and City of Arvada #AEC13870. We confirm the permitting jurisdiction for your property during the first conversation.

Other rooms people often build alongside a home spa: home theaters, custom wine cellars, and cigar lounges. Planning storage too? See our custom closets page. Most of these rooms go in as part of a basement finish; see our pages for Denver, Lakewood, Aurora, Centennial, Parker, and Castle Rock.

Home Spa and Sauna FAQs

Can you build a sauna in my basement?

Usually, yes. Basements are a common location. We check the electrical panel, ventilation routes, and moisture conditions, then build the sauna with insulation, vapor control, and the heater clearances the manufacturer requires.

What’s the difference between a steam room and a sauna in construction?

A sauna is a dry, wood-lined room with an insulated, vapor-controlled shell. A steam room is a fully waterproofed, vapor-tight tiled enclosure with a sloped ceiling, sealed door, drain, and a steam generator outside the room.

Will a sauna or steam room overload my electrical panel?

It depends on your panel and the equipment. Sauna heaters and steam generators commonly need dedicated 240-volt circuits. We check capacity first and plan a subpanel or service upgrade if needed.

Can a cold plunge go on an upper floor?

Sometimes. Water is heavy, so we check whether the floor can carry a filled plunge and reinforce it if needed. Drainage and equipment noise matter too.

Do I need a permit for a home spa?

Typically, yes, because of the plumbing, electrical, and mechanical work involved. We confirm with your building department and handle the permit and inspections.

How much does a home spa cost?

The features you choose, equipment, waterproofing scope, electrical upgrades, drainage work, and finishes drive cost. We don’t publish a price list; you get a written, itemized estimate after a walkthrough.

Request a Free Home Spa Estimate

Tell us which features you want and where. We’ll set up a walkthrough and follow up with a written scope and estimate.

Call (720) 223-9003 or email sean@ggcbuilds.com.