THIA Pushes Unified Tiny Home Standards and Municipal Tools Nationwide

The International Code Council and the Tiny Home Industry Association are pushing ICC/THIA Standard 1215 toward a Spring 2026 finish, and if the document lands on schedule, it will hand building officials across the country a single technical reference for permitting tiny homes of 400 square feet or less as permanent residences, whether those homes sit on a foundation or roll in on a chassis.

The standard's first draft cleared a November 24, 2025 public comment deadline, advancing through ICC's ANSI-consensus procedures, which require documented input from all materially affected stakeholders before any final ballot. The formal title, "Design, Construction, Inspection and Regulation of Tiny Houses for Permanent Occupancy," signals a direct evolution of IRC Appendix AQ, the 2018 code provision that first carved out a legal pathway for sub-400-square-foot dwellings but left each jurisdiction free to adopt or ignore it, generating the patchwork enforcement THIA has spent years fighting.

THIA, a 501(c)(6) nonprofit launched in 2016, describes its mission as "making tiny possible." Its current push layers Standard 1215 advocacy with two municipal-facing tools: the Tiny House Resource Map, a state-by-state tracker of approved legislation and builder models, and the "Bring Tiny to Your Town" program, a step-by-step playbook for community advocates taking their case to local decision-makers. Together, the tools are designed to convert Standard 1215's technical legitimacy into actual zoning ordinances at the county level.

Not everyone in the community views the standard as clean progress. In May 2025, ICC submitted a revised project initiation notification expanding the standard's scope to include "Small Residential Units," structures up to 1,200 square feet, drawing formal objections from critics including the Tiny House Alliance USA. Opponents argue the SRU category dilutes tiny-house-specific protections and introduces unresolved conflicts with federal chassis preemption rules that govern homes on wheels.

Those chassis and titling questions carry direct consequences for buyers. Standard 1215 does not automatically resolve how a tiny house on wheels converts from personal property to real property, and lenders still need that classification before underwriting. Builders and buyers planning a 2026 close should track the OSMTH 1215 committee's final ballot language and confirm whether their state building code division intends to reference the new standard.

THIA President Dan Fitzpatrick, who also serves as Director of Government Relations for the American Tiny House Association, has framed ICC-backed standards as the baseline local jurisdictions should reference when drafting new tiny home ordinances. His prior work includes co-authoring language behind Colorado's HB22-1242, a Movable Tiny Home bill that state advocates have since held up as a model for replication elsewhere. The association's searchable membership directory now connects builders and suppliers to regional decision-makers, giving city planners a vetted starting point when drafting permitting language.

A finalized Standard 1215 carries no zoning mandate. What it carries is the same institutional weight ICC standards bring to every other residential construction category, enough to move a hesitant planning commission from "we don't have a code for that" to "here is the one we are adopting.