Buying a Telluride Property With an Existing ADU: The Due Diligence Checklist
When buying a Telluride property that already has an accessory dwelling unit, a buyer should verify seven things before writing an offer: the permit chain of title, the governing jurisdiction (Town of Telluride, Town of Mountain Village, or unincorporated San Miguel County), any deed restriction recorded on the parcel, short-term rental eligibility under the current local ordinance, whether the unit's current use matches its permitted use, financing and appraisal treatment of the ADU, and the insurance, utility, and HOA carrying-cost picture. An existing ADU is an asset only when each of those checks resolves cleanly. This guide walks the audit.
Why an existing ADU changes a Telluride transaction
An ADU does not behave like a finished basement or a bonus room. It is a second dwelling on the title, and the local code, recorded restrictions, and short-term rental rules treat it as such. That status cuts two ways for a buyer.
When the ADU is legal, conforming, and free of restrictive use covenants, it expands the property's value: multi-generational living, caretaker housing, long-term workforce rental, or licensed short-term rental income. When the ADU is non-conforming, deed-restricted to workforce use the buyer did not anticipate, or operating in violation of the current short-term rental ordinance, the unit becomes a liability that flows directly into appraised value, financing terms, insurance cost, and post-closing legal exposure.
The categorical difference between asset and liability is what the audit below is designed to surface, before earnest money goes hard.
What are the three categories of existing ADUs you will encounter in Telluride?
In practice, an ADU showing up on a listing in the Telluride region will fall into one of three categories, and the category determines the rest of the conversation.
Category 1: Fully permitted and conforming. The original building permit was pulled with the relevant building department, the certificate of occupancy was issued, the unit complies with the current local code, and no deed restriction limits its use. This is the cleanest case and, in the Telluride market, the least common.
Category 2: Permitted but restricted. The unit was permitted, but a recorded restriction governs how it can be used. The most frequent variant in the Town of Telluride is a workforce-housing deed restriction requiring occupancy by a qualified local worker at controlled rents. Mountain Village Owners Association covenants and sub-association rules can layer additional restrictions on top of the Town's code. The unit is legal, but its allowable use may not match the buyer's plan.
Category 3: Non-conforming or unpermitted. The unit exists physically, but the permit record does not support it as a legal dwelling. Sellers often describe these as "grandfathered." A grandfathered claim only holds if the unit was lawful when built and has not been substantially altered since. Many "grandfathered" ADUs in the Telluride region cannot withstand a permit-record audit, which is why this check belongs at the front of the due diligence process rather than at the end.
The Telluride ADU Buyer's 7-Point Audit
The framework below is the audit I run before recommending an offer on any property in the Telluride region that includes an existing accessory dwelling unit. It treats the unit not as a feature in the listing copy but as a distinct legal object with its own permit history, restriction status, allowable use, and carrying cost. The seven checks are sequential. A failure at point one rarely resolves at point seven.
1. Permit chain of title
Pull the original building permit, the approved plans, the inspection record, and the certificate of occupancy from the jurisdiction with authority over the parcel. For parcels inside the Town of Telluride, that is the Town's Planning & Building Department. For parcels inside the Town of Mountain Village, that is the Town's Community Development Department. For unincorporated parcels, that is the San Miguel County Planning Department and Building Department. A unit without a permit, a final inspection, and a certificate of occupancy is not a legal ADU regardless of how it appears in person.
2. Jurisdictional classification
Confirm which body of code governs the ADU. The Town of Telluride Land Use Code, the Mountain Village Community Development Code, and the San Miguel County Land Use Code treat ADUs differently on lot size, gross floor area cap, setbacks, parking, owner-occupancy, and short-term rental eligibility. House Bill 24-1152, signed by Governor Jared Polis on May 13, 2024, set a statewide ADU framework but applies only to subject jurisdictions inside a metropolitan planning organization with a population of at least 1,000. Source: Colorado General Assembly, HB24-1152 bill text and history (as_of_date: 2024-05-13). Neither Telluride nor Mountain Village qualifies, and San Miguel County is not a subject jurisdiction, so each of the three local codes controls its own parcels. The pillar guide on Colorado ADU laws and Telluride zoning walks the layered framework in full.
3. Deed-restriction check
Order the title commitment early and read every recorded document on the parcel, not just the headline restrictions. The Town of Telluride has long used workforce-housing deed restrictions to keep specific units affordable for qualified local workers; those restrictions run with the land and bind every future owner. Mountain Village parcels frequently sit under the Telluride Mountain Village Owners Association (TTMVOA) declaration plus a sub-association declaration, each with its own ADU-relevant covenants. San Miguel County unincorporated parcels can have private covenants from the original subdivision plat. A deed-restricted ADU is not an ADU the buyer can use freely.
4. Short-term rental eligibility
Short-term rental rules diverge sharply across the three jurisdictions and have been revised multiple times since 2021. The Town of Telluride, the Town of Mountain Village, and San Miguel County each operate separate short-term rental licensing programs. An ADU permitted as a long-term secondary unit may not be eligible for a short-term rental license under the current ordinance. A deed-restricted workforce unit is not STR-eligible. A non-conforming unit cannot be lawfully licensed. Verify current STR eligibility with the licensing office in the controlling jurisdiction before underwriting any rental income into the purchase.
5. Current use versus permitted use
The unit's actual day-to-day use must match what the permit authorizes. An ADU permitted as a "secondary dwelling" and operated as a nightly rental without an STR license is in violation. An ADU recorded as deed-restricted workforce housing and occupied by an out-of-area tenant is in violation. A garage conversion permitted as storage and used as a residence is unpermitted living space. The buyer inherits the violation at closing, including any enforcement action the relevant jurisdiction may bring against the prior use.
6. Financing and appraisal complications
Lender treatment of ADU income, and appraiser treatment of ADU value, depend on the unit's legal status. Conventional lenders following Fannie Mae and Freddie Mac guidelines generally credit ADU rental income only when the unit is legal, conforming, and supported by lease or market comparables. A non-conforming ADU is often valued by the appraiser as additional finished square footage rather than as a separate income-producing unit, which compresses appraised value relative to what the listing implies. Renovation-extension products such as the Fannie Mae HomeStyle Renovation loan and the FHA 203(k) treat ADUs under specific eligibility rules; a Telluride-area mortgage professional should confirm structure-specific treatment.
7. Insurance and carrying-cost reality
A property with an ADU usually requires a different insurance structure than a single-family residence: separate dwelling coverage for the ADU, liability coverage that contemplates a tenant or short-term guest, and higher overall premiums at altitude. Mountain Village properties carry TMVOA dues plus, in many cases, sub-association dues. Utility metering varies: in-town ADUs may share or split meters with the primary residence; County parcels on well and septic must demonstrate adequate capacity to serve the additional bedroom load. The full carrying cost picture rarely appears in the listing.
What are the common deal-killers at inspection?
Even where the permit record looks clean on paper, a physical inspection of an existing ADU surfaces issues that change the deal. Four patterns recur in the Telluride region.
Electrical sub-panel violations. Many older ADUs were wired before the current National Electrical Code adoption cycle in the relevant jurisdiction. Undersized sub-panels, missing arc-fault protection, and improperly bonded neutrals are common findings.
Lack of separate, code-compliant egress. A basement ADU without an egress window of the required size, or a converted garage without a code-compliant exit path, is not a legal sleeping space.
Kitchen separation that does not meet code. A "kitchenette" with a microwave and a hot plate is not a legal kitchen under most local code adoptions, which means the unit may not qualify as a separate dwelling.
Septic over-capacity on unincorporated parcels. A primary residence septic system sized for three bedrooms cannot legally absorb an additional bedroom from an ADU without engineered expansion and Colorado Department of Public Health and Environment (CDPHE) review. This is the most common County-side ADU killer.
A separate ADU-specific inspection, alongside the standard whole-property inspection, typically surfaces these items before contingency expiration.
What should a buyer ask the listing agent or seller before writing an offer?
The questions below are the practical version of the seven-point audit. Each one is intended to surface a documentary answer, not a verbal reassurance.
- Can you provide the original building permit, the approved plans, and the certificate of occupancy for the ADU?
- Which jurisdiction (Town of Telluride, Town of Mountain Village, or San Miguel County) issued the permit, and what zone is the parcel in?
- Is the ADU subject to any recorded deed restriction, and can I see the recorded instrument?
- Does the property currently hold a short-term rental license for the ADU, and under which ordinance?
- Is the ADU's current use the same use the permit authorizes?
- Has the assessor reassessed the parcel since the ADU was added, and what was the resulting valuation impact?
- Are there any open code-enforcement matters, pending HOA design-review actions, or unresolved building inspection items on the unit?
Where the answer is verbal rather than documentary, the buyer or the buyer's broker should pull the supporting record directly from the relevant department before the inspection contingency expires.
What are the red flags in the property disclosure?
Colorado's standard real estate contract and the Colorado Real Estate Commission's Seller's Property Disclosure form ask sellers to disclose known material facts, including building permits, code violations, and rental history. Source: Colorado Real Estate Commission resources (as_of_date: 2026-05-27). The form is informative, but ADU disclosures frequently use vague language that warrants follow-up.
Watch for the phrases "grandfathered," "added by prior owner," "permit status unknown," "rental history available upon request," and "no known restrictions." Each of these is a prompt for documentary verification rather than a closed answer. A disclosure that lists an ADU but cannot point to a permit number, a CO date, or a recorded restriction document is a disclosure that has more to discover.
Pair the disclosure review with a written request to the relevant jurisdiction for the parcel's permit history. The pattern I see when ADUs become a deal-killer in the Telluride region is that the disclosure is technically accurate while leaving the most important questions structurally unanswered.
Frequently Asked Questions
How do I know if a Telluride ADU is legal?
A Telluride ADU is legal when the relevant jurisdiction issued a building permit for it, the building department signed off on final inspection, and the certificate of occupancy is on file. Pull the permit record from the Town of Telluride Community Development Department for in-town parcels, the Mountain Village Planning and Community Development Department for Mountain Village parcels, or the San Miguel County Planning Department for unincorporated parcels. Absent a permit, a final inspection, and a CO, the unit is not legally an ADU regardless of physical appearance.
Can I short-term rent the ADU at a property I am buying in Mountain Village?
Short-term rental eligibility for a Mountain Village ADU depends on the parcel's zone, the unit's legal status, TMVOA and sub-association covenants, and the current Mountain Village short-term rental ordinance. Eligibility cannot be assumed from a current rental history. Verify with the Town of Mountain Village's licensing office and read the TMVOA and sub-association covenants before relying on STR income.
What is a deed-restricted ADU and should I avoid it?
A deed-restricted ADU carries a recorded restriction on the title that controls how the unit can be used, most commonly a workforce-housing restriction requiring occupancy by a qualified local worker. The restriction runs with the land and binds every future owner. Whether to avoid it depends on the buyer's intended use; the unit is not unusable, but it is not freely usable either. Read the recorded restriction in full before closing.
Does an existing ADU help or hurt the appraisal?
A legal, conforming ADU generally supports appraised value, because the appraiser can credit a second dwelling and, where the rental market supports it, income. A non-conforming or unpermitted ADU often does not add proportionate value; the appraiser may treat the space as additional finished square footage rather than a separate dwelling, which reduces the contribution to appraised value relative to what the listing copy implies.
Can I get a mortgage on a property where the ADU is non-conforming?
Most conventional lenders following Fannie Mae and Freddie Mac guidelines can lend on a property with a non-conforming ADU, but they will typically not credit ADU income toward debt-to-income qualification and the appraiser will adjust value accordingly. Some lenders require the non-conforming use to be cured before close. A Telluride-area mortgage professional should be consulted early, because the lender's treatment can change the maximum offer the buyer can support.
Who do I call to verify ADU permit status before making an offer?
Call the planning or community development department in the jurisdiction with authority over the parcel: the Town of Telluride Community Development Department for parcels inside town, the Town of Mountain Village Planning and Community Development Department for Mountain Village parcels, or the San Miguel County Planning Department for unincorporated parcels. The relevant department will provide the parcel's permit history; the recorder's office, the County Clerk and Recorder, provides the recorded deed restriction documents.
Closing: how to use this checklist
An existing ADU is one of the more leveraged variables in a Telluride-area purchase. The same physical structure can be a $300,000 value-add or a $200,000 problem depending on the permit record, the recorded restrictions, the short-term rental status, and the appraisal treatment, and the buyer rarely has the data to make that call from the listing alone.
The seven-point audit above is the framework I use to bring that data to the surface before contingency expiration. Pair it with a Colorado attorney's review of any recorded restriction, a Telluride-area mortgage professional's read on financing structure, and a local builder's input on any deferred maintenance the unit shows at inspection. The deeper context on the underlying code framework sits in the Colorado ADU laws and Telluride zoning complete guide, the local picture sits in the ADUs in Telluride overview, and the broader market sits in Why Telluride. For current Telluride and Mountain Village listings or a parcel-specific ADU review, the Town of Telluride and Mountain Village community pages are the right starting points.
Anne-Britt Østlund is the broker-owner of Mountain Rose Realty, a member of REALM Global, and affiliated with the Institute for Luxury Home Marketing. Reach her at (970) 759-4886 or ab@mountainrose.co. This guide is informational and does not constitute legal, tax, or financial advice; recorded deed restrictions should be reviewed with a Colorado attorney, financing structure with a licensed mortgage professional, and tax treatment with a tax advisor.