Basement remodeling in Denver

How much does it cost to remodel a basement in Denver?

Most metro Denver basement finishes cost $30,000 to $90,000, according to one Denver builder's 2026 guide. A remodel adds the cost of tearing out the old finish and hauling it away.

The builder splits the range into three levels.

• Basic, $30,000 to $50,000: insulated walls, drywall, LVP or carpet and recessed lights
• Mid-range, $50,000 to $70,000: adds a full bath, a bedroom with egress and upgraded finishes
• High-end, $70,000 to $90,000 or more: theaters, wet bars, second kitchens and premium materials

What are common basement remodel mistakes in Denver?

The costliest Denver basement remodel mistakes happen before the drywall goes up, and each has a simple fix. One Denver builder calls finishing over a moisture problem the most expensive mistake a Denver homeowner can make.

The same builder calls a quote without permits a red flag. Unpermitted work causes trouble at sale and can void insurance cover for claims. These five steps prevent the common mistakes.

• Fix damp walls or a wet floor before framing
• Test for radon before the walls close
• Float every wall that sits on a moving slab
• Put an escape window in every new bedroom
• Get permits written into the quote

Do you need a permit to remodel a basement in Denver?

Yes, for most remodels. Denver Community Planning and Development requires a permit for changes to load-bearing walls, new or resized doorways and windows, and new egress windows.

Some projects also need a sewer use and drainage permit. Denver asks for one if the home sits in a floodplain or the work digs within two feet of the sewer line.

Exterior work on a landmark home or in a historic district needs a certificate of appropriateness. That covers a new egress window, so apply for it before the building permit.

Can you lower an old Denver basement floor for more headroom?

Yes, by digging out the floor and underpinning the foundation. One Denver builder puts that at $15,000 to $40,000.

The same builder says many older Denver homes have basement ceilings of 7 feet or lower. Wash Park, Congress Park and Capitol Hill homes often face this choice.

Measure before you pay for it. The 2024 residential code allows 6 feet 8 inches for living space created in an existing basement, and 6 feet 4 inches under beams and ducts. Denver's 2025 code builds on the 2024 editions, and your contractor confirms any local change.

How is remodeling an old basement different from finishing a new one?

A remodel starts with what is already there. Your contractor opens enough of the old work to check the wiring, plumbing and framing.

Find out whether the old finish was permitted. Walls nailed straight to the slab crack as the clay moves, and they may need reframing.

The 2024 code does not demand an escape window when you alter an existing basement. The rule applies once you add a bedroom, and each new sleeping room needs its own.

Should you retest for radon before remodeling a Denver basement?

Yes, if the basement has no mitigation system or no recent test. The Colorado Department of Public Health and Environment says every county is in EPA radon Zone 1 and all homes should test.

A remodel opens walls and ceilings, which makes it the easiest time to route a mitigation pipe. One Denver builder puts radon mitigation in Denver at $900 to $2,500.