# ESA Letter in Thornton, CO: Small Landlords, No Colorado Exemption

> Thornton rents out fewer of its homes than Colorado as a whole, so more tenants answer to one owner. Colorado's disability rules still reach that owner.

- Source: https://supportanimal.com/blog/colorado-emotional-support-animal/thornton/
- Publisher: Support Animal (supportanimal.com)
- Updated: 2026-08-07
- License note: informational content; not legal or medical advice.

## Key facts

- Population: 146,689
- Households renting: 28.6%
- Typical pet deposit (as a pet): Capped at $300
- Typical pet rent (as a pet): Capped at $35/mo
- Breed/weight limits common: yes
- Pet fees, deposits, and breed limits with a valid ESA letter: none (FHA reasonable accommodation)

## Thornton rents fewer of its homes than Colorado does

Of the 50,566 occupied housing units in Thornton, 14,457 are rented. That is a
renter share of 28.6%, measured against 33.8% for the state, on the 2020-2024
American Community Survey five-year estimate. Thornton is an owner-occupied
city with a rental market inside it, not the reverse.

The consequence shows up the moment you ask about an animal. A smaller renter
share means more of the rentals here are single houses, townhomes and basement
units held by people who own one or two properties. No portal, no
accommodation form, often no written pet policy: just a landlord, a phone
call, and a fast answer.

## The exemption your landlord may have read about does not exist here

Owners of small properties often believe fair housing rules were written for
somebody else, and the belief has a real source. Federal law does not reach an
owner-occupied building of four units or fewer, so a duplex owner living behind
the other wall really is outside part of the federal Act.

Colorado wrote its statute differently. There is no owner-occupied
small-building exemption for disability in Colorado law. The one carve-out for
small properties, at C.R.S. § 24-34-502(1.5)(a), covers three units or fewer
and applies only to the source-of-income rules, vouchers and where your money
comes from. It does nothing for a disability request.

What does apply is C.R.S. § 24-34-502.2(2)(b): refusing a reasonable
accommodation in rules, policies, practices or services, where it is necessary
to give a person with a disability equal opportunity to use and enjoy a
dwelling, is discrimination. C.R.S. § 24-34-502(1)(k) makes breaking that
section an unfair housing practice. Building size is not part of the test.

## Colorado has been doing this since 1959

Worth knowing when a Thornton landlord treats this as new. Colorado enacted
the first statewide fair housing law in the country in 1959, nine years
ahead of the federal Fair Housing Act. Its rules have never tracked the
federal ones.

## The state code picks up four new rules

The signing happened on May 19, 2026. The effective date is August 12, 2026.
House Bill 26-1045 explains itself: rescinded federal guidance is what
Colorado is putting back in state law.

Four pieces of it matter to a Thornton tenant. C.R.S. § 24-34-301(2.5)
supplies the term. An assistance animal is one that provides therapeutic
emotional support to a person with a disability, or works, performs tasks, or
assists that person. Service animals and emotional support animals both sit
inside it.
C.R.S. § 24-34-501(3.5) defines the accommodation itself as an exception or
adjustment to a rule, policy, practice or service, which is what a landlord's
no-pets line is. C.R.S. § 24-34-502.2(2)(b)(II)(A) presumes that allowing an
assistance animal in housing is a reasonable accommodation.
C.R.S. § 24-34-502.2(2)(b)(II)(B) presumes that banning them outright is
discriminatory.

## The presumption has a condition, and Thornton is where it bites

Read the proviso on the first presumption. It runs in your favour so long as
the housing provider has been given an opportunity to engage in an
interactive accommodation process.

In a managed building, that opportunity happens by accident, the portal
records it. Renting from an individual owner, nothing gets recorded unless you
record it. Send the request by email or dated letter, keep the copy, and send
it before the animal moves in. A tenant who moves a dog in first and cites the
statute afterwards hands the owner a procedural argument for free.

## Being asked for a letter is not the refusal

C.R.S. § 24-34-502.2(2)(b)(II)(C) protects the question, not the refusal. A
provider who requests reasonable documentation (of the disability, or of the
need the animal answers) has not discriminated, and neither has one who runs
a good faith interactive process. Where the disability or the need is obvious,
the questions stop. What they may cover is bounded by their purpose: whether
you have a disability, and whether the
animal relates to it. Breed, weight, obedience training and any online listing
fall outside. No Colorado body registers or certifies assistance animals, so
there is nothing to produce there and nothing you can be faulted for lacking.

C.R.S. § 24-34-501(1.3) is the definition underneath all of it: disability
includes a mental impairment, meaning any behavioural, mental or psychological
disorder.

## Who Colorado permits to write it

Colorado licenses the writer, and the rule splits by profession. Under
C.R.S. § 12-245-229(3)(a), a mental health licensee (a psychologist, licensed
counsellor, social worker, or marriage and family therapist), cannot make the
finding unless they have met the patient **in person**. Physicians work under
C.R.S. § 12-240-144(3)(a), which permits in person or by telemedicine. The two
rules are not interchangeable, and the therapist's is the stricter one.

Whoever it is must produce a written finding on the disability and a
**separate** written finding on the disability-related need, and must be
sufficiently familiar with the patient and legally and professionally
qualified.

That paperwork also answers the accusation. C.R.S. § 18-13-107.3 makes it an
offence to intentionally misrepresent an entitlement to an assistance animal
in order to get a housing accommodation, but only where a written or verbal
warning came first, which is an element the prosecution has to prove. It has
been a class 2 civil infraction since March 1, 2022, with fines of $25, then
$50 to $200, then $100 to $500. The statute names its own defence: a written
finding under C.R.S. § 12-240-144(1)(a) or § 12-245-229(1)(a) is an
affirmative defence, and lacking one is expressly not evidence of the offence.

## Money, insurance and the deposit on a rented house

An ordinary pet in Colorado costs what C.R.S. § 38-12-106 allows and no more:
$300 of additional deposit, refundable, and additional rent of $35 a month or
1.5% of the monthly rent, whichever is *greater*. An approved assistance animal
is not a pet, and dropping those charges is the exception to a policy that
C.R.S. § 24-34-501(3.5) contemplates.

Insurance is the objection Thornton hears most, because so much of its rental
stock is single houses on homeowner's or dwelling fire policies.
C.R.S. § 10-4-110.8(16) closed that route on January 1, 2024. An insurer may
not refuse or surcharge such a policy over a dog's breed, and may not ask about
breed except whether the dog has been declared dangerous. And on the damage
argument, C.R.S. § 24-34-502(1)(a)(III) provides from August 12, 2026 that
presence alone does not make an animal a direct threat to health or safety, and
that substantial physical damage to other people's property may not be presumed
from it, though documented, specific conduct by that particular animal may
still be weighed.

When the tenancy ends, C.R.S. § 38-12-103 as rewritten on January 1, 2026
governs the deposit. Thirty days to return it, or up to sixty where the lease
says so. The landlord carries the burden of proving both that a withholding
was not wrongful and what the actual damages were. A retention at or above
125% of those damages carries a presumption that it unreasonably exceeds them.
Carpet has its own rule: unless new carpet went down in the past ten years, it
cannot be deemed substantially and irreparably damaged, a live point in older
Thornton rental houses. A written
request obliges the landlord to hand over photographs, invoices, estimates or
inspection reports within fourteen days. Wrongful retention costs treble
damages plus attorney fees and costs, after seven days' written notice of
intent to sue.

## Where to take it in Adams County

Thornton is in Adams County, and free help is organised by county rather than
city. Colorado Legal Services covers Adams from its Denver office at
1560 Broadway, Suite 1100, on 303-837-1313. Its Adams County eviction clinic
sits at the Justice Center, 1100 Judicial Center Drive in Brighton, on
Wednesday and Friday from 8 to 11 a.m., helping only at the courthouse named
on your summons, on your court date. Maiker Housing Partners is the
county's housing authority. The Denver Metro Fair Housing Center takes metro
fair housing questions, and Colorado Housing Connects runs a bilingual
statewide renter line on 844-926-6632.

The city itself runs three free home rehabilitation programmes (CodeCAP, Help
for Homes and Paint-a-Thon), funded with HUD Community Development Block
Grant money for repairs touching health, safety, accessibility and energy
efficiency. Ask Thornton's Housing and Homelessness team what you qualify for.

A discrimination charge, though, goes to the Colorado Civil Rights Division on
303-894-2997, with a Spanish line on 720-432-4294. C.R.S. § 24-34-504(1) gives
you one year from the unfair housing practice, and the Division says plainly
that it cannot extend that for any reason. One trap to avoid: sending intake
through CaseConnect is not filing a charge. The charge is drafted and signed
after intake, so a submission made in the final fortnight of the year saves
nothing. Once filed, most housing cases are dual-filed with HUD, because the
Division is a HUD-certified Fair Housing Assistance Program agency.

## What Thornton landlords can and cannot do

**Cannot:**
- Cannot operate a complete prohibition on assistance animals, which C.R.S. § 24-34-502.2(2)(b)(II)(B) presumes to be discriminatory from August 12, 2026
- Cannot treat the mere presence of an assistance animal as a direct threat to health or safety, or presume it will cause substantial physical damage to the property of others, under C.R.S. § 24-34-502(1)(a)(III)
- Cannot refuse to make reasonable accommodations in rules, policies, practices or services where necessary to afford a person with a disability equal opportunity to use and enjoy a dwelling, under C.R.S. § 24-34-502.2(2)(b)
- Cannot rely on the small-landlord and owner-occupied exemptions that exist under federal law, because Colorado's disability provisions carry no equivalent, the three-or-fewer-units carve-out at C.R.S. § 24-34-502(1.5)(a) applies only to the source-of-income rules
- Cannot charge a pet deposit or pet rent for an approved assistance animal, because waiving that charge is an exception to a policy within the definition of reasonable accommodation at C.R.S. § 24-34-501(3.5)
- Cannot take more than a three-hundred-dollar refundable pet deposit, or more than thirty-five dollars a month or one and one-half percent of rent, whichever is greater, for an ordinary pet under C.R.S. § 38-12-106
- Cannot justify a breed restriction by pointing at its insurer, since C.R.S. § 10-4-110.8(16) bars an insurer from pricing or refusing a policy on dog breed and from asking about breed at all
- Cannot keep any part of a deposit without a written statement of the exact reasons within thirty days, and cannot charge for carpet replacement across a unit where the carpet was not replaced within the previous ten years, under C.R.S. § 38-12-103
- Cannot place a lien on the animal itself for unpaid rent, under C.R.S. § 38-20-102(3)(a)

**Can:**
- May request reasonable documentation supporting the claim of disability or the disability-related need, and may run a good faith interactive process, without that being discrimination, unless the disability or the need is obvious, under C.R.S. § 24-34-502.2(2)(b)(II)(C)
- May act on documented, specific conduct of the animal that poses a direct threat to health or safety or causes substantial physical damage to property
- May hold a tenant responsible for damage the animal actually causes, provided it exceeds normal wear and tear, did not preexist the tenancy, and is substantiated with the photographs, invoices or estimates C.R.S. § 38-12-103(8) requires on request
- May ask for a walk-through inspection at the end of the tenancy, as may the tenant, under C.R.S. § 38-12-103(1.5)

## How to get an ESA letter in Thornton

1. **Check that you qualify**, Answer a short screening about how your condition affects daily life in Thornton. No diagnosis paperwork needed up front. (About 5 minutes: free)
2. **Connect with a licensed professional**, You are matched with a provider licensed for Colorado clients who reviews your situation in a telehealth evaluation. (Telehealth evaluation)
3. **Complete your evaluation**, The professional evaluates whether an emotional support animal alleviates symptoms of a condition recognized in the DSM-5. Honest evaluations, not everyone qualifies. (Most of Our Applicants Qualify)
4. **Receive your signed letter**, Your letter arrives on the professional's letterhead with their license number: the documentation Colorado landlords may lawfully request. (Typically within days of approval)
5. **Send it to your landlord**, Submit the letter with a short reasonable-accommodation request. Pet fees, pet deposits, and breed limits no longer apply to your animal in Thornton. (Protection under FHA + state law)

## Conditions that can qualify for an ESA

No fixed government list exists. A licensed professional evaluates whether an animal alleviates symptoms of a DSM-5-recognized condition, commonly:

- Generalized anxiety disorder
- Major depressive disorder
- Post-traumatic stress disorder (PTSD)
- Panic disorder
- Social anxiety disorder
- Obsessive-compulsive disorder (OCD)
- Bipolar disorder
- Attention-deficit/hyperactivity disorder (ADHD)
- Phobias with housing impact
- Chronic stress affecting daily function

## Housing help in Thornton

- [Colorado Civil Rights Division, Housing Discrimination](https://ccrd.colorado.gov/housing-discrimination) (state agency)
- [City of Thornton Housing & Homelessness](https://www.thorntonco.gov/community-culture/housing-homelessness) (city agency)
- [Maiker Housing Partners (Adams County housing authority)](https://maikerhp.org/) (housing authority)
- [Denver Metro Fair Housing Center](https://www.dmfhc.org/) (fair housing)
- [Colorado Legal Services](https://www.coloradolegalservices.org/get-help/) (legal aid)
- [Colorado Housing Connects](https://coloradohousingconnects.org/) (tenant help)

## Frequently asked questions

### My Thornton landlord owns one house and says fair housing law does not apply to them. Is that right?

No. That belief comes from federal law, which does not reach an owner-occupied building of four units or fewer. Colorado's law does reach it. C.R.S. § 24-34-502.2(2)(b) makes it discrimination to refuse a reasonable accommodation that a person with a disability needs for equal opportunity to use and enjoy a dwelling, and C.R.S. § 24-34-502(1)(k) makes a violation of that section an unfair housing practice. The only small-property carve-out in the statute, at C.R.S. § 24-34-502(1.5)(a), covers properties of three units or fewer and applies only to the source-of-income rules, not to disability.

### There is no leasing office to file a request with. How do I ask?

In writing, to whoever signs your lease, before the animal moves in. This matters more in Thornton than in a city of managed buildings, because no portal is going to timestamp the request for you. From August 12, 2026, C.R.S. § 24-34-502.2(2)(b)(II)(A) presumes that allowing an assistance animal in housing is a reasonable accommodation, but only where the housing provider has been given an opportunity to engage in an interactive accommodation process. An email or a dated letter is what creates that opportunity and proves it happened.

### My landlord asked for a letter. Is asking illegal?

It is not. C.R.S. § 24-34-502.2(2)(b)(II)(C) states that a housing provider does not commit a discriminatory housing practice solely by requesting reasonable documentation of the disability or of the disability-related need, or by running a good faith interactive process, unless the disability or the need is obvious. What the request may cover is bounded by its purpose. The breed, the weight, the training history and any online listing sit outside it, and no Colorado agency issues a registration or certificate for an assistance animal in the first place.

### The owner of my Thornton rental house says their homeowner's insurance bars the breed. Can they use that?

That answer stopped working in Colorado on January 1, 2024. C.R.S. § 10-4-110.8(16) forbids an insurer from refusing, cancelling or surcharging a homeowner's or dwelling fire policy because of a dog's breed, and forbids the insurer from asking about breed at all except whether the dog has been declared dangerous. Since so many Thornton rentals are single houses carried on exactly those policies, this is the local version of the objection, and the carrier is not permitted to do the thing the owner is describing.

### Can a landlord say no because the animal might damage the house?

Not on a guess. From August 12, 2026, C.R.S. § 24-34-502(1)(a)(III) provides that the mere presence of an assistance animal is not a direct threat to the health or safety of others and is not presumed to result in substantial physical damage to the property of others. A housing provider may still consider documented, specific conduct by the individual animal that poses a direct threat or causes substantial damage. Also relevant: C.R.S. § 24-34-502.2(2)(b)(II)(B) presumes that a complete prohibition of assistance animals in housing is discriminatory.

### Who in Colorado is allowed to write my documentation?

A licensed professional who has actually assessed you, under rules that differ by profession. C.R.S. § 12-245-229(3)(a) requires a mental health licensee (psychologist, licensed counsellor, social worker, or marriage and family therapist), to have met the patient in person. A physician has more room: C.R.S. § 12-240-144(3)(a) accepts a visit in person or by telemedicine. Two written findings then have to come out of whichever appointment you had, one on the disability and a separate one on the disability-related need, from a licensee sufficiently familiar with the patient and legally and professionally qualified. A current letter from someone who genuinely examined you is the strongest document you can hold.

### Where does a Thornton renter go for free help?

Thornton sits in Adams County, so Colorado Legal Services covers it from the Denver office at 1560 Broadway, Suite 1100, on 303-837-1313. Its Adams County eviction clinic runs Wednesday and Friday from 8 to 11 a.m. at the Justice Center, 1100 Judicial Center Drive in Brighton, and helps people on their court date at the courthouse named on the summons. Maiker Housing Partners is the Adams County housing authority. The Denver Metro Fair Housing Center takes fair housing questions across the metro, and Colorado Housing Connects runs a statewide bilingual renter helpline on 844-926-6632. Discrimination charges themselves go to the Colorado Civil Rights Division, on 303-894-2997, within one year under C.R.S. § 24-34-504(1).

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Get evaluated by a licensed provider: https://my.supportanimal.com/qualify?sa_source=blog&sa_medium=blog&sa_campaign=esa-guides&sa_content=markdown&ref=blog&sa_term=colorado-emotional-support-animal%2Fthornton