Before You Build in Caldwell, ID: Permit & Rule Checklist (2026)

Caldwell City Code section 10-02-07 limits open and solid residential fences to a maximum of six feet along side and rear property lines. Within twenty feet of the front property line, heights step down. Fences in a vision triangle are capped at three feet for traffic visibility.

Under the Idaho Residential Code adopted by Caldwell, fences up to seven feet are exempt from a building permit, but all fences must still comply with zoning Section 10-02-07 for height, setback, and material. Masonry walls, retaining walls over four feet, and pool barriers can trigger a separate permit.

Caldwell's zoning code sets fence heights and a "good side out" rule but does not assign cost-sharing for boundary fences. Idaho Code Title 35 governs shared partition fences: an adjoining owner who is notified must build half, or the neighbor can build it and recover half the cost with a lien.

Caldwell follows the Idaho Residential Code, which exempts retaining walls four feet or less (measured from the bottom of the footing to the top) from a building permit unless they support a surcharge or impound flammable liquids. Taller walls require a permit and engineering. Walls must also respect zoning setbacks and vision triangles.

Most standard fence materials are allowed in Caldwell under Section 10-02-07, but the code distinguishes "open" from "solid" fencing for height and bars dangerous wire types outside commercial/industrial zones. Historic and arterial-frontage rules add material limits, and street-frontage fences must show the finished side outward.

Building a pool in Caldwell requires a building permit. The city has adopted the 2018 International Residential Code (including Appendix G for pools and spas) per City Code 12-01-01, and the Building Safety Division reviews and inspects pool construction under that code.

Caldwell's zoning code (10-12-03-1) does not set its own pool-barrier dimensions; it states pool barriers 'shall be provided and regulated under the adopted building codes.' That code is the 2018 IRC, Appendix G, which requires a barrier at least 48 inches high with self-closing, self-latching gates.

Pool safety in Caldwell is governed by the adopted 2018 International Residential Code, Appendix G (City Code 12-01-01), enforced through the building-permit process. Zoning Code 10-12-03-1 adds a 10-foot property-line setback and points barrier requirements to that building code.

Caldwell's pool definition (Code 10-01-10) covers above-surface pools more than 30 inches deep, so above-ground pools are regulated. They must meet the 10-foot property-line setback (Code 10-12-03-1) and the adopted 2018 IRC Appendix G barrier rules, and are permitted in interior side and rear yards.

Caldwell regulates spas and hot tubs through the adopted 2018 International Residential Code, Appendix G (City Code 12-01-01), which covers pools, spas and hot tubs. The zoning code's 10-foot pool setback (10-12-03-1) applies, and barrier rules are enforced through that building code.

Caldwell allows an accessory dwelling unit by right on single-family lots. ADUs must be at least 200 square feet, are limited to one bedroom, and may not use a recreational vehicle or mobile home. The ADU cannot be subdivided off the parcel and must meet accessory-structure setbacks.

Caldwell has no separate 'garage conversion' ordinance. Converting a garage into living space is reviewed as a building-permit and zoning matter, and if it creates a second independent dwelling it must meet the city's accessory dwelling unit standards in 10-12-03-1, including the one-bedroom limit and accessory-structure setbacks.

Caldwell sheds and detached accessory buildings under 200 square feet need no setback; those 200 to under 600 square feet must sit at least 5 feet from interior side and rear lot lines. In residential zones an accessory structure may not be larger than the principal home without a special use permit, and height is capped by district.

Caldwell regulates carports as accessory structures under City Code 10-02-04. A detached carport follows the same size-based setbacks as other accessory buildings - no setback under 200 square feet, 5 feet for 200 to under 600 square feet - and the same district height caps of 22 or 33 feet.

A tiny home on a permanent foundation is treated as a regular dwelling or ADU in Caldwell and must meet building and zoning code. A tiny home on wheels or a recreational vehicle is prohibited for use as an ADU under City Code 10-12-03-1, and Idaho generally bars living in an RV on a standard residential lot.

Recreational fires, campfires and ceremonial fires are allowed in Caldwell without a permit if the fire stays under three feet in diameter and two feet high. Fire-extinguishing equipment such as a connected water hose must be readily available, and a competent adult must attend until the fire is out.

Caldwell City Code Article 17 bans most outdoor burning. Weed-abatement and special-circumstance fires require a Caldwell Fire Department permit. All burning is prohibited when the Treasure Valley air quality index hits 60 or winds exceed 10 mph, and burn piles are capped at 3 feet by 2 feet.

Caldwell's Tree Ordinance (Chapter 10, Article 8) governs trimming of public and street trees. "Topping" of public trees is prohibited except in limited cases, and pruning of public trees is overseen by the City Forester. Caldwell is a long-running Tree City USA community.

Removing a public or street tree in Caldwell requires City Forester involvement, and anyone who removes or destroys a public tree must replace it with trees of equivalent dollar value. Private trees on private property are far less restricted. Article 8 of the City Code governs.

Caldwell requires new developments to irrigate landscaping with non-potable (surface/well) water through pressurized irrigation built to Caldwell Municipal Irrigation District standards, conserving drinking water. Section 10-07-12 governs irrigation; dry landscaping is allowed where no irrigation water right exists.