Important: Homzora is a housing research publisher, not a law firm, and nothing on this page is legal advice. This article is general information about the law as published by government and court sources at the time of writing, and it may not reflect later changes or the facts of your situation. Reading it does not create an attorney and client relationship. For advice about your situation, contact a licensed attorney or a legal aid organization in your state.
In the city of Denver, about 171,900 of 335,400 occupied homes, or 51.2 percent, are rented, according to the U.S. Census Bureau’s 2020 to 2024 American Community Survey (Homzora Denver dataset, Table B25003). The median gross rent is $1,831 a month (Homzora Denver dataset, Table B25064). Rodents, roaches, bed bugs, and mold are among the most common problems renters face, and the law usually expects landlords to keep a home fit to live in.
This guide explains what Colorado law and any local rules in Denver say about pests, bed bugs, and mold, how to report a problem, and what to do if the landlord does not respond.
What Colorado law says
Colorado tenants must promptly notify the landlord in writing or electronically when they know or reasonably suspect bed bugs, and the landlord must have a qualified inspection done within 96 hours of notice (law effective January 1, 2020) (C.R.S. § 38-12-1002 (HB19-1328 enrolled text)). A Colorado landlord must report inspection results within two business days and begin treatment within five business days if bed bugs are found, and pays inspection and treatment costs (C.R.S. § 38-12-1003). Colorado landlords must give at least 48 hours written or electronic notice before entry for bed bug inspection or treatment; tenants must cooperate and pay the costs of preparing their unit (C.R.S. § 38-12-1004).
A Colorado landlord may not offer for rent a unit the landlord knows or reasonably suspects has bed bugs, and a landlord who violates the bed bug law is liable for the tenant’s actual damages (C.R.S. §§ 38-12-1005, 38-12-1006). Under Colorado’s warranty of habitability, a home is uninhabitable if it has mold associated with dampness (minor surface mold in normally damp areas excluded) (C.R.S. § 38-12-505(1)(a)). A Colorado home is also uninhabitable if it substantially lacks appropriate extermination in response to rodent or vermin infestation, in the unit or in common areas (C.R.S. § 38-12-505(1)(b)(VIII)).
Free help in Denver
Colorado Legal Services provides free civil legal aid at 303.837.1313 (Colorado Legal Services). For other services, call 211 (211.org).
Signs of a pest or mold problem
- Droppings, gnaw marks, or nests in cabinets, closets, or behind appliances.
- Small blood spots or dark stains on sheets and mattress seams, which can signal bed bugs.
- A musty smell, visible mold growth, or recurring condensation on walls and windows.
- Water stains on ceilings or walls, which often point to a leak feeding mold.
- Insects appearing in multiple rooms or returning after you clean.
How to report it the right way
- Tell the landlord in writing as soon as you notice the problem, and describe what you see and where.
- Attach dated photos or video, and save any pest you can safely capture in a sealed bag.
- Ask when treatment or repairs will happen and who will do them.
- Prepare the unit as the exterminator instructs, and keep a copy of those instructions.
- If nothing happens, contact the local code enforcement or health office listed above.
A sample repair request
Date: 2026. To: [landlord]. Re: [Pests] [Mold] at [address]. Since about 2026, I have seen [describe the problem] in [rooms]. Photos are attached. Please arrange [treatment] [repair of the leak and removal of the mold] as soon as possible and tell me when someone will come. I will prepare the unit as needed. Sincerely, [name].
Bed bugs: what helps
- Do not move furniture or bedding to other rooms or throw it on the curb untreated, which can spread bed bugs.
- Wash and dry bedding and clothing on high heat.
- Keep clutter off the floor to make treatment more effective.
- Tell the landlord before you treat on your own; some laws and leases require professional treatment.
- Check used furniture carefully before bringing it home.
Mold: prevention and cleanup
Mold grows where moisture stays. Use bathroom fans, open windows when weather allows, wipe condensation, and report leaks right away. Small areas of mold on hard surfaces can often be cleaned with soap and water, but large areas, mold caused by a leak, or mold inside walls usually need the landlord to fix the moisture source. If anyone in your home has asthma or another health condition that mold may affect, talk with a doctor and mention it in your written request.
Who pays for pest control
Who pays depends on state and local law, the lease, and sometimes on who caused the problem. Many laws put the duty on the landlord to keep the unit fit to live in, while tenants are expected to keep their own unit reasonably clean and to report problems promptly. Read your lease, and ask the landlord in writing to explain any charge for pest treatment.
Mistakes to avoid
- Waiting to report. Infestations and mold spread quickly.
- Reporting only by phone. A written record shows when the landlord was told.
- Withholding rent without following the law. Rent remedies have strict steps.
- Using strong chemicals on your own. Some products are dangerous indoors and can scatter pests.
Before you sign a lease
- Ask whether the unit or building has had pests, bed bugs, or mold in the past year.
- Look under sinks, inside cabinets, and around windows for droppings, stains, or water damage.
- Ask how pest control is handled and how often the building is treated.
- Ask how quickly the landlord responds to leaks.
Build your evidence file
Landlord and tenant disputes are usually decided by documents. Keep these together from the day you sign:
- The signed lease, every addendum, and every renewal.
- Receipts or bank records for the deposit and each rent payment.
- Dated photos and video of every room at move in and move out.
- Copies of every repair request and the landlord’s replies.
- Every notice you send or receive, with proof of delivery.
Keep copies somewhere other than your phone, such as an email to yourself, so they survive a lost device.
Fair housing
The federal Fair Housing Act prohibits discrimination in rental terms because of race, color, religion, sex, familial status, national origin, or disability (42 U.S.C. § 3604). HUD accepts complaints (HUD, File a Complaint).
Shared walls and building wide problems
Pests travel between units through walls, pipes, and hallways, so one tenant cleaning alone often cannot solve the problem. Talk with neighbors, and if several units are affected, ask the landlord in writing for a building wide plan. Some local laws require landlords to inspect or treat neighboring units, as noted above where it applies.
Keeping records
Keep a simple log of each sighting, report, treatment visit, and follow up, with dates and photos. Save the exterminator’s instructions and any inspection reports. Those records are the most useful evidence if you need code enforcement, a court, or a legal help office to step in.
Preparing for a pest treatment
Treatments work best when the unit is ready. Exterminators commonly ask tenants to clear cabinets and closets, move furniture away from walls, bag clothing and linens, and keep pets and people out for a set time. Ask for the written preparation list and the products to be used, follow it closely, and photograph the prepared unit. If you need help preparing because of age or disability, ask the landlord in writing for a reasonable accommodation.
Health concerns
Pests and mold can aggravate asthma and allergies, and some pest control products carry their own risks. If anyone in your household is pregnant, very young, older, or has a respiratory condition, mention it in your written request and ask what products will be used. For medical questions, talk with a doctor or call your local health department.
Your deposit and move out
Landlords can usually deduct for damage the tenant caused, but not for pests or mold that came from building conditions or that the landlord failed to fix after notice. Keeping your written reports and the landlord’s responses helps you contest a deduction later. Photograph the affected areas again at move out.
Frequently asked questions
Does my Denver landlord have to pay for an exterminator?
Often, under the habitability rules described above, though the details depend on state and local law and on what caused the problem. Ask in writing and keep the reply.
Can I break my lease over mold or pests?
Sometimes, if the problem makes the unit unfit to live in and the landlord fails to fix it after proper notice, but the steps are strict. Get advice from a free legal help office before you move out.
Who do I call if the landlord ignores me?
Use the local code enforcement or health office described above, and keep a copy of your written requests to show what you already asked for.
Legal notice
Homzora is not a law firm and does not provide legal advice. Laws, court rules, and local programs change, and how they apply depends on your facts. Before you act on anything in this article, confirm the current rules with the court, a licensed attorney, or a legal aid organization.
Sources
- Homzora Denver dataset, Table B25003
- Homzora Denver dataset, Table B25064
- C.R.S. § 38-12-1002 (HB19-1328 enrolled text)
- C.R.S. § 38-12-505(1)(a)
- Colorado Legal Services
- 211.org
- 42 U.S.C. § 3604
- HUD, File a Complaint