CodeMandatory
Required heating
IRC R303.8Description
Dwellings in regions where the winter design temperature is <60°F must have heating capable of maintaining 68°F at a point 3 ft above the floor in habitable rooms.
Why this exists
Some climates need active heat to be habitable; the IRC sets a minimum interior temperature target.
Measurements
| Property | Operator | Value | Unit | Note |
|---|---|---|---|---|
minInteriorTemp | min | 68 | F |
Categories
EnergyVentilation
Source
ICCno manifest entry
International Residential Code (2024)
Section: R303.8
Published 2024-01-01 · last verified 2026-05-09
Solver enforcement
Browsable only — the solver does not currently enforce this directive (no spec-level data to check against). This entry exists so the architect personas can cite it in conversation and the user can read what the rule says.
Related directives
- Natural light in habitable rooms · IRC R303.1
- Carbon monoxide alarms in sleeping areas · IRC R315
- Garage HVAC duct prohibition · IRC R302.5.2
- Natural ventilation in habitable rooms · IRC R303.1 (vent)
- Bathroom ventilation · IRC R303.3
Last reviewed 2026-05-09.