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Parker, CO Accessory Structures: ADU Rules (2026)

Heavy Restrictions

Compiled from the official code textEditor Martyn O'NeillLast verified September 2026

ADU rules in Parker, CO, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.

Key Facts

ADU status: Prohibited in all zoning districts
Governing section: LDO § 13.05.050(d)(1)
State mandate: Rejected HB 24-1152 via Ord. 1.644 (2025)
Alternative: AG-zone caretaker residence, 1 per 10 acres
Max fine: $499 per day of violation

ADU Eligibility Quick-Check

An Accessory Dwelling Unit (ADU) is a smaller, independent living unit on the same lot as a single-family home: converted garages, detached cottages, basement or attic conversions, and attached additions all qualify. Most states have streamlined ADU permitting since 2020, but local rules still control size, height, and setback.

Is your lot zoned single-family or multi-family residential?
Does your lot have at least 1,200 sq ft of buildable space?
Is your existing home owner-occupied (in most states this is not required, but some require it for ADU permits)?
Will the ADU stay under your state's size cap (commonly 850-1,200 sq ft for detached)?
Can you provide one off-street parking space (waived in many states within 0.5 mi of transit)?

If you answered 'yes' to most of these, you likely qualify in Colorado under recent ADU streamlining laws. The Parker, CO rules below cover local size, height, and setback requirements.

Summary

The Town of Parker prohibits accessory dwelling units in every zoning district. Town Council reaffirmed the ban on May 5, 2025 by rejecting the state ADU mandate in House Bill 24-1152, so no garage apartment, basement unit or backyard cottage can be permitted as a second dwelling on a residential lot anywhere in Parker.

(1)Accessory dwelling unit. Accessory dwelling units are prohibited in all districts. [3] ... Note— On May 5, 2025, the Town Council adopted Ordinance No. 1.644, Series of 2025, rejecting House Bill 24-1152.

View official code

Full Breakdown

Parker Municipal Code § 13.05.050(d)(1), part of the Land Development Ordinance's accessory-use standards, states flatly that accessory dwelling units are prohibited in all districts. That single sentence controls every residential zoning district in the Town of Parker, from SF1 large-lot lots to multifamily-zoned parcels. Colorado's 2024 legislature passed House Bill 24-1152 to force municipalities to allow ADUs near transit, but Parker used its home-rule authority under Article XX of the Colorado Constitution to opt out: the Town Council adopted Ordinance No. 1.644, Series of 2025 on May 5, 2025, specifically rejecting that state mandate.

Because Parker is a home rule town, the Town Council's own ordinance controls land use matters of local concern rather than the state statute. Anyone wanting a caretaker unit instead should look at the separate caretaker residence allowance in § 13.05.050(d)(3), which permits one caretaker residence per ten acres, but only in the AG agricultural zoning district; this option does not apply to standard single-family lots. Community Development's Planning Division reviews all building permit and site plan applications and will reject any proposal that adds a second dwelling unit, kitchen, or separate entrance configured as an independent residence on a lot zoned for one principal dwelling.

Violations & Fines

Building or occupying an unpermitted second dwelling unit violates the Land Development Ordinance and is enforceable under Parker Municipal Code § 13.01.080. The Town can fine the property owner up to $499 per violation, with each day the illegal unit exists counted as a separate offense, and the Town Attorney may also seek injunctive relief or abatement through Municipal Court to force removal of the unauthorized unit.

Frequently Asked Questions

Can I build a garage apartment or basement rental unit in Parker?

No. Parker Municipal Code § 13.05.050(d)(1) prohibits accessory dwelling units in every zoning district in the Town, including detached garage apartments, basement units, and backyard cottages, regardless of lot size.

Does Colorado's new ADU law override Parker's ban?

No. Parker is a home rule municipality, and on May 5, 2025 the Town Council adopted Ordinance No. 1.644, Series of 2025, specifically rejecting House Bill 24-1152, the state law that otherwise pushed cities to allow ADUs.

Is there any way to get a second residence approved on my property?

Only the caretaker residence option in § 13.05.050(d)(3) comes close, and it is limited to one caretaker residence per ten acres in the AG agricultural zoning district, not standard residential lots.

Sources & Official References

[1]Parker Municipal Code § 13.05.050 - Accessory uses and structures

Other rules in Parker

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All Parker rules

How Parker compares: Easiest Cities to Build an ADU·Compare Parker to another location·View the Colorado accessory structures overview

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