Renovating an Older Denver Home: What to Check First

Renovating an older Denver-area home starts with four checks before a single wall comes down: the foundation and the soil under it, the permits the project needs, whether lead paint or asbestos is present, and whether the electrical panel and wiring meet current insurance standards. Skip any one of these and a Front Range renovation turns into a change order, a stop-work order, or a denied insurance claim.

Start With the Foundation and the Soil Under It

Denver metro sits on expansive bentonite clay soil that swells when it absorbs water and shrinks as it dries. That movement is the leading cause of foundation cracks in Front Range homes built before 1980, when soil testing and engineered foundations were less consistent. Before framing anything, have a structural engineer look at the crawlspace or basement walls for step cracks, doors that stick, and floors that slope more than an inch over 20 feet.

A soils report and a foundation inspection run a few hundred dollars and catch problems that cost tens of thousands of dollars to fix once tile and drywall are in the way. Read how Denver-area foundation cracks get diagnosed and repaired before scheduling structural work.

What Requires a Permit in Denver and Aurora

Denver and Aurora require a building permit for structural changes, electrical work beyond a fixture swap, plumbing that relocates a fixture or adds a line, and anything that changes the footprint or egress of the home. Cosmetic work — paint, flooring, cabinets, trim — does not need one. Each city runs its own permit desk and inspection schedule, so a Lakewood or Littleton renovation follows that city's process, not Denver's, even a few miles away.

Pulling the permit triggers the inspections that protect a homeowner: a rough-in inspection before drywall closes up wiring and plumbing, and a final inspection before sign-off. Skipping the permit skips those inspections too.

Colorado Has No Statewide Contractor License — Denver Requires One Anyway

Colorado does not license general contractors at the state level; anyone can call themselves a general contractor. Denver fills that gap locally: the city requires a licensed contractor for electrical, plumbing, mechanical, and most general building work performed inside city limits, and it publishes a searchable list of who holds an active license. Aurora, Lakewood, and Littleton run comparable local licensing for the same trades. Before signing a contract, check the contractor's license number against the city's own database rather than a business card.

Mechanic's Liens: Protect Yourself When You Hire Subcontractors

Under Colorado's mechanic's lien law (C.R.S. Title 38, Article 22), a subcontractor or material supplier who is not paid for work on a home can file a lien against the property itself — even after the homeowner already paid the general contractor in full. The subcontractor missed the payment, not the homeowner, but the lien attaches to the title regardless. Ask the general contractor for lien waivers from every subcontractor and supplier as each draw goes out, and hold the final payment until those waivers are in hand.

Lead Paint and Asbestos in Pre-1978 Denver Homes

Any Denver-area home built before 1978 is assumed to have lead-based paint until a test proves otherwise. Federal rules require a lead-paint-certified contractor for any renovation that disturbs more than six square feet of painted surface in a pre-1978 home — sanding, scraping, or cutting into a painted wall all count. Homes built before the early 1980s can also carry asbestos in pipe insulation, floor tile adhesive, and textured ceiling finishes. Test both before demolition starts.

Knob-and-Tube Wiring and Federal Pacific Panels

Homes built before the 1950s in neighborhoods like Baker, Berkeley, and Sunnyside sometimes still carry knob-and-tube wiring, which most Colorado insurers will not cover without a full rewire. Federal Pacific "Stab-Lok" electrical panels, common in homes built through the 1970s, get flagged by insurers and inspectors alike for a documented breaker-tripping defect. A renovation is the moment to replace both — start by comparing home insurance quotes to see how much a rewire and panel swap lowers the premium, then fold the upgrade into the permitted project.

Adding a Bathroom Without Breaking the Slab

Many older Denver basements were never roughed in for a bathroom, and cutting through a slab that sits on clay soil adds cost and mess. An upflush macerating toilet system, like the Saniaccess 2, pumps waste up to the existing sewer line above the floor, which lets a basement bathroom or ADU bathroom go in without breaking concrete. Price it against a full slab cut before finalizing a basement renovation budget.

Altitude and Gas Appliances

At 5,280 feet, gas furnaces, water heaters, and ranges need a rating or conversion kit for high-altitude installation — a furnace sized for sea level runs inefficiently and stalls a Denver inspector's approval at the rough-in stage. Confirm with the contractor that every gas appliance in the renovation carries a high-altitude rating before it goes in the wall.

Hail Season, Snow Load, and Timing the Project

Colorado's hail season runs from spring through September, and roofing crews book up fastest during the Front Range's busiest storm months. Scheduling a roof or exterior renovation outside that stretch means a shorter wait for a contractor and less chance the project competes with a storm-driven insurance claim for the same crew. Roof framing on any Denver-area addition also has to carry the region's design snow load, which runs higher in foothills communities like Golden and Evergreen than in central Denver — the structural engineer's report should specify the number for the exact address.

Denver's 2022 Energy Code and Xcel Energy Rebates

Denver's 2022 energy code raises the insulation, window, and air-sealing standard for any permitted addition or major remodel, not only new construction — a renovation that opens exterior walls has to meet the current code on the way back together. Xcel Energy offsets part of that cost with rebates for insulation, efficient furnaces, and heat pump water heaters; a contractor familiar with Denver permitting can fold the rebate paperwork into the project timeline.

HOA, Metro District, and Historic District Review

An HOA or metro district can require its own design approval before a permit application even goes in, and that review adds weeks a project schedule needs to plan around. Check the HOA review requirements for renovations and the Denver HOA rules and fees guide before submitting plans. Homes inside a Denver historic district or individually landmarked carry an extra layer: Denver's Landmark Preservation Commission reviews exterior changes — windows, siding, additions visible from the street — before the city issues a building permit, regardless of what the HOA says.

Adding an ADU to an Older Home

Denver's citywide zoning update opened accessory dwelling units to most residential lots, which makes an older home's detached garage or basement a candidate for a rentable unit during the same renovation that addresses the foundation and wiring. Read the Denver ADU, zoning, and historic district guide and Denver's ADU policy explained for buyers, sellers, and house-hackers before drawing plans.

What Pays Off at Resale on the Front Range

The recoup ranges below hold across Denver, Aurora, Lakewood, Littleton, Colorado Springs, and Fort Collins, because contractor costs and buyer expectations move together across the corridor.

Disclosing Unpermitted Work When You Sell

Colorado's Seller's Property Disclosure form asks directly whether any work on the home was done without a permit, and a "no" that turns out false can unwind a sale after closing. Buyers and their lenders treat unpermitted square footage — a finished basement, an added bedroom, a converted garage — as an appraisal red flag. Pulling the permit during the renovation is the cheaper path; closing out an old, unpermitted project later can require opening finished walls for an inspector to verify the work. See what preparing and adding value before selling actually requires when the renovation is aimed at a future sale.

Where to go next

• Search every home for sale in Colorado
• Older homes vs. new construction: the maintenance reality for Denver buyers
• Foundation red flags to check before buying a Denver home
• Pricing your Colorado home to sell
• Denver property taxes: how the bill changes after a renovation

Talk to the Kenna Real Estate Group

The Kenna Real Estate Group walks Front Range homeowners through which renovations are worth permitting now and which upgrades matter most if a sale is on the horizon. Call or text 303-955-4220. A live person answers. Not a robot, not a phone tree. Search every home for sale in Colorado while the renovation plan comes together.