Two bills, one deadline

Governor Brad Little signed Senate Bills 1352 and 1354 on April 1, 2026, after the Idaho Legislature passed both in late March.

SB 1352 bars cities from prohibiting starter-home subdivisions on parcels of at least four acres, and prevents them from requiring lots larger than 1,500 square feet within those subdivisions. SB 1354 removes local government and homeowners association bans on accessory dwelling units.

Both carry a compliance deadline of February 1, 2027, by which cities must amend their comprehensive plans and land-use regulations. The ADU deadline was moved back from an earlier October 1, 2026 date by amendment.

What the 1,500 square foot figure means

Minimum lot size is one of the most effective tools a local government has for limiting how many homes can be built on a given acre. A quarter-acre minimum caps a four-acre parcel at sixteen houses before any other rule applies.

By capping the minimum a city may impose at 1,500 square feet inside a starter-home subdivision, SB 1352 does not require small lots; it removes the city's ability to forbid them. Whether builders use the allowance depends on what buyers will accept and what the arithmetic of land, servicing and construction supports.

Analysis: legislation of this type changes the permitted envelope, not the market. Idaho's outcome over the next several years will show how much of the state's affordability problem was zoning capacity and how much was construction cost, land price and financing — a natural experiment worth watching precisely because the legal change is so specific.

The votes were close

SB 1352 passed the Senate 25 to 10 and the House 36 to 34 — a two-vote margin in the lower chamber. SB 1354 passed the Senate by the same 25 to 10 and the House more comfortably, 47 to 23. The sponsor was Senator Ben Toews of Coeur d'Alene.

Those tallies are the clearest available evidence of contested support. No specific opposition statements from Idaho municipal governments or the Association of Idaho Cities were located in the sources reviewed, so the shape of local objections is not documented here beyond the roll calls.

What the laws leave alone

The ADU bill explicitly preserves local building codes, fire safety rules, floodplain regulations, water and sewer requirements and environmental-hazard regulations. Historic districts and historic properties are exempt from the starter-home mandate in SB 1352.

Those carve-outs matter more than they may appear. A city that cannot ban small lots outright retains servicing standards, and infrastructure capacity remains a real constraint on where subdivisions can go regardless of what zoning permits.

Part of a wider package

SB 1352 and SB 1354 were not the whole of Idaho's 2026 housing session. A companion bill, SB 1279, separately voids restrictive covenants that strictly prohibit or unreasonably restrict starter-home subdivisions, effective July 1, 2026, closing off a private-law route around the new statutory floor.

House Bill 800 amended Idaho Code section 67-6509A to strengthen requirements that cities amend their comprehensive plans and zoning to allow manufactured homes on any lot zoned for single-family use, extending a siting mandate that previously applied unevenly; it passed the House 60-6-4 on March 9, 2026. A companion, House Bill 647, addressed the same manufactured-housing provisions together with a covenant ban.

House Bill 706 authorizes local governments, for the first time under Idaho's building code, to permit residential apartment buildings of up to six stories to be built with a single interior stairway rather than the two required by the International Building Code, provided the building carries an automatic sprinkler system, fire-rated stairway enclosures and doors, and limits of four units per floor and 6,000 square feet per story. It passed the House 63-7-0 on March 24, 2026 and the Senate 18-17 on April 1, 2026, becoming law April 2 with a July 1, 2026 effective date. Single-stair construction is cheaper per unit than the standard double-loaded corridor design because it needs less circulation space, and a handful of other states have passed similar exceptions to encourage smaller infill apartment buildings.