Tiny Homes in Costilla County, Colorado

600 square feet is the floor -- and it has to be a permanent structure

Costilla County's Land Use Code sets a 600-square-foot minimum for any permanent, single-family dwelling, and that minimum applies to a tiny house the same way it applies to any other home. A tiny house built to a permanent foundation and meeting applicable building-code standards can qualify as a legal dwelling here if it clears that 600-square-foot line -- but a smaller structure doesn't get an exception just because it's marketed as a tiny home.

The county's definition of a qualifying tiny home specifically excludes recreational park trailers, RVs, semitrailers, and intermodal shipping containers -- none of those count as a permanent dwelling under the code no matter how they're finished out inside. A tiny house permanently built on a vehicle chassis is allowed, but only if it isn't self-propelled and is installed and secured to county and state standards; a mobile or wheeled tiny home cannot be used as a permanent, full-time primary residence here. Any qualifying structure also needs a visible street address and secure utility connections before it's treated as move-in ready.

Living on-site during construction: the temporary RV permit

If your plan is to live in an RV or a wheeled tiny home while you build a permanent, code-compliant house on the same parcel, Costilla County has a specific mechanism for that rather than a blanket prohibition: a temporary permit for RV living during active home construction, capped at 180 days per parcel within any 12-month period. To use it, you need a source of fresh water already in place -- a well or a cistern -- and a septic system installed, not merely planned. This ties directly into the county's broader camping rules: without any permit, camping on your own land is capped at 14 days in any 3-month period, so the 180-day construction permit is the route around that shorter general limit, not an exception from needing a permit at all.

Don't treat this permit as a way to live indefinitely in an RV while a tiny home project stalls -- it's tied to active construction of a permanent dwelling, and the 180-day cap is a hard outer limit per parcel per year. If your build timeline is likely to run longer than that, ask the Planning and Zoning Department directly how renewal or a second permit period is handled before you commit to that living arrangement.

What qualifies, what doesn't

• Qualifies as a permanent dwelling: a tiny house of at least 600 square feet, on a permanent foundation, built to applicable code, with secure utility connections and a visible street address.
• Qualifies as a temporary living arrangement only: an RV or wheeled tiny home used under the 180-day construction permit, with a well/cistern and septic system already installed.
• Does not qualify as a dwelling under the code at all: recreational park trailers, standard RVs, semitrailers, and intermodal shipping containers, regardless of interior finish.
• Not permitted: living full-time in an RV or wheeled tiny home as a permanent primary residence outside the construction-permit window.