Residential Code, Explained
Original plain-English explanations of the code questions builders and homeowners actually search — with the controlling numbers and section citations from the model codes (2021 IRC, 2023 NEC) that most states adopt. Your jurisdiction may amend them: check your local page.
Deck Footing Requirements — Depth, Size & Frost Protection
Deck footings live or die by two questions: are they below the frost line, and are they big enough for the load? The IRC answers the first with your j…
Deck Ledger Attachment — Bolt Schedule, Flashing & Lateral Load
Most deck failures are ledger failures. The IRC treats ledger attachment with a prescriptive fastener schedule, mandatory flashing, and a short list o…
Where GFCI Outlets Are Required — The NEC 210.8 Location List
GFCI protection is location-driven: the NEC lists the places in a dwelling where receptacles must be GFCI-protected, and the list has grown nearly eve…
Egress Window Requirements — Size, Sill Height & Window Wells
Every sleeping room and every basement with habitable space needs an emergency escape and rescue opening — the "egress window." The four numbers that …
Stair Code Requirements — Rise, Run, Width & Headroom
Residential stairs are governed by four numbers most builders can recite: 7-3/4, 10, 36, and 6-8. Miss the uniformity tolerance, though, and a stair t…
Handrail & Guardrail Code — Heights, Grip Size & the 4-Inch Sphere
Handrails are for grip; guards are for falls. The IRC gives each its own trigger, height, and geometry — and ties them together with the 4-inch sphere…
Smoke & Carbon Monoxide Alarm Placement — Where the Code Puts Them
Smoke alarm placement in a dwelling is a fixed list: each bedroom, outside each sleeping area, and every story. Carbon monoxide alarms attach to the s…
Garage Fire Separation — Drywall, Doors & the No-Direct-Opening Rule
The house-garage separation is not a fire wall — the IRC just wants a gypsum membrane and a decent door between the car and the living space. Table R3…
Where Tempered (Safety) Glass Is Required — The Hazardous Locations List
The code never says "tempered glass" is required everywhere — it lists hazardous locations where glazing must be safety-rated (tempered or laminated).…
Receptacle Spacing Rules — The 6/12 Rule, Countertops & Walls
The NEC’s receptacle-placement logic is simple: no point along a wall should be far from a plug, and countertops get their own denser rules. It all li…
These are BuildSpec’s own summaries — not reproductions of ICC or NFPA text. For the authoritative language, follow the official-code links on each page, and confirm your jurisdiction’s adopted edition and amendments on its permit page.