STAMP REQUIREMENTS · CO
Do you need an architect's stamp in Colorado?
Colorado does not require an architect for one- to four-family dwellings or their accessory buildings, including additions and alterations that keep them within those limits (C.R.S. §12-120-403).
What the law says
C.R.S. §12-120-403(1) exempts one-, two-, three- and four-family dwellings and their accessory buildings, plus additions, alterations and repairs that don’t push the building past those limits.
Where the exemption stops
- Up to four dwelling units.
- Cities and counties keep the power to adopt building codes that ask for more (§12-120-403(2)).
When an engineer is still required
Snow loads, expansive soils and foundations on slopes commonly bring in a Colorado-licensed engineer, and many jurisdictions require engineered foundations for new homes.
What this means if you're using a drafting service
A drafting service can prepare the architectural set for a Colorado house, ADU or addition. Check your jurisdiction’s foundation and snow-load requirements before ordering.
ArchWorkPro drafts permit sets for $1 per square foot of drawn area with a $1,200 minimum, or $195 per sheet for new construction under 1,200 sq ft. We don't seal drawings. When your project needs an engineer or architect, you hire them directly and we draft to their direction. See what a permit set includes or permit drawings for owner-builders.
City pages for Colorado, with plan check times and energy code details: Aurora.
Questions
Do I need an architect to build a house in Colorado?
Colorado does not require an architect for one- to four-family dwellings or their accessory buildings, including additions and alterations that keep them within those limits (C.R.S. §12-120-403).
Do I need an engineer's stamp in Colorado?
Snow loads, expansive soils and foundations on slopes commonly bring in a Colorado-licensed engineer, and many jurisdictions require engineered foundations for new homes.
Can a drafting service prepare my permit plans in Colorado?
A drafting service can prepare the architectural set for a Colorado house, ADU or addition. Check your jurisdiction’s foundation and snow-load requirements before ordering.
Who has the final word on stamps for my project?
Your local building department. State law sets the floor, and the building official can ask for a licensed professional's seal on any portion that falls outside the code's prescriptive rules. Ask before you order drawings.
Sources
Read from the statute and regulation text on . This is general information, not legal advice. Your building department decides what your specific project needs, and laws change; confirm before you rely on it.
Other states: California · Texas · Florida · Arizona · Washington · Oregon · New Jersey
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