Learning Center · Home Codes
The Building Code for a Texas Home: What the IRC Says, Trade by Trade
The International Residential Code, the IRC, is the building code Texas cities use for houses. It reaches well past the roof. Here is what it says about the parts of a home we work on, in plain words, with the section number so you can read it yourself.
Updated October 28, 2026
Read This First
The short version
- Inside city limits, Texas law makes the IRC the building code for houses, and each city adopts its own edition.
- Round Rock, Austin and Hutto are on the 2024 edition; Georgetown, Pflugerville, Cedar Park and Leander are on 2021.
- Where expansive soils are known to exist, roof water must discharge at least 5 feet from the foundation or into an approved drainage system.
- Siding goes over a continuous water-resistive barrier, with flashing at windows, doors and where a roof meets a wall.
- The IRC lists painting among work exempt from its permit rule, cities set their own permit rules, and an exemption never means the code stops applying.
Questions about roof, gutter or siding work on your home? Use Get Help or call or text 512-575-5052.
Short version: 2 min. Full page: 8 min. Want the detail? Each section below opens with a tap, or switch to Full at the top to open them all.
Texas Law
What the IRC is, and where it applies in Texas
Texas law makes it the house code inside city limits, and each city picks its edition.
Inside city limits
Texas Local Government Code Section 214.212 adopts the IRC, as it existed on May 1, 2012, as the residential building code for cities. It applies to all construction, alteration, remodeling, enlargement and repair of homes in a city. A city may adopt a newer edition, and may add local amendments after a public hearing and by ordinance.
Your city’s edition
Round Rock, Austin and Hutto list the 2024 edition as adopted; Georgetown, Pflugerville, Cedar Park and Leander list 2021. Austin adds local amendments, including a wildfire code; see the Austin wildfire roof guide. The roof code guide, linked in the next section, has the dates we read for each city.
Outside city limits
A county applies these standards only if it opts in, and then only to new houses and to additions that grow a house or duplex in square footage or value by more than half (Sections 233.151 to 233.153). If the county has opted in and a city has adopted a building code for its extraterritorial jurisdiction, the city’s code controls there. On our reading, a repair outside city limits generally is not covered by a residential building code, though other county rules may apply.
Roofing
The roof, and the attic under it
Roof coverings follow Chapter 9; attic ventilation follows Section R806.
Roof coverings
Chapter 9 sets the underlayment, drip edge, flashing and how each roof covering goes on, and it makes the maker’s installation instructions part of the code. Our roof code guide walks through it line by line.
Attic ventilation
An enclosed attic needs cross ventilation, with openings between 1/16 and 1/4 inch, or screened to that size, and protected from birds, rodents and snakes (R806.1). The minimum open vent area, after screens and louvers, is 1/150 of the vented space. It may drop to 1/300 when 40 to 50 percent of it sits within 3 feet of the ridge, measured vertically, and the rest in the bottom third; the other condition, a vapor retarder, applies only in colder climate zones, not Texas (R806.2). The attic ventilation guide shows the math.
Gutters
Roof water and drainage around the house
On swelling clay, roof water must land at least 5 feet from the foundation.
Roof water
Where expansive or collapsible soils are known to exist, a house needs a controlled way to carry roof water to the ground at least 5 feet from the foundation walls, or to an approved drainage system (R801.3). Much of the clay around Round Rock swells when wet and shrinks when dry, so ask your city whether it applies this section.
Grading the yard
The ground must fall at least 6 inches within the first 10 feet away from the foundation. Where a lot line or wall prevents that, drains or swales carry the water away, and hard surfaces within 10 feet slope at least 2 percent away from the house (R401.3).
What it means for gutters
The code does not name gutters. It asks for a controlled method of water disposal, and on our reading gutters with downspouts that discharge 5 feet out are the usual way to meet it. See gutters and foundations on clay soil, or our gutter services.
Services
Siding, house wrap and flashing
A continuous water-resistive barrier behind siding, and flashing wherever water can get in.
Behind the siding
An outside wall must keep water from building up inside it: a water-resistive barrier behind the siding, and a way for water that gets past the siding to drain out (R703.1.1). At least one layer of that barrier runs continuous to the top of the wall (R703.2). Concrete and masonry walls, and tested wall systems, have exceptions.
Flashing
Corrosion-resistant flashing is required at places including windows and doors, where a chimney meets a frame wall, under and at the ends of sills and copings, above projecting wood trim, where a porch or deck attaches, at every wall and roof intersection, and at built-in gutters; overlapped flashing laps in shingle fashion (R703.4).
Clearance
Unless the maker says otherwise, vinyl, insulated vinyl and polypropylene siding stays at least 6 inches above the ground and 1/2 inch from decks, roofs and slabs (R703.3.1). More on repair choices in siding repair or replace.
Services
The drywall between the garage and the house
Garage-side gypsum board is a fire separation, so a repair puts back what the table calls for.
The rule
Table R302.6 calls for at least 1/2 inch gypsum board, or equivalent, on the garage side between the garage and the house and its attic, and at least 5/8 inch Type X gypsum board, or equivalent, under rooms above the garage. The same section number holds in the 2021 edition.
After a leak
When drywall on that wall or ceiling is replaced, the new board should match what the table calls for, not whatever is on hand. See drywall after a roof leak.
Services
Solar panels on the roof
Rooftop panels carry the roof’s fire rating, and every roof penetration is flashed.
What the code asks
A rooftop panel system must be supported by the roof under it, carry the fire classification the code requires for the roof, and have its roof penetrations flashed and sealed under Chapter 9. That is Section R329.4 in the 2024 edition and R324.4 in 2021.
During a reroof
Panels typically come off before a reroof and go back after it, and the mounts should be flashed into the new roof. See solar detach and reset.
Painting
Painting, permits, and what an exemption does not do
Painting is on the IRC permit exemption list, but the code still applies, and lead rules may too.
No permit for finish work
R105.2 lists painting, papering, tiling, carpeting, cabinets, countertops and similar finish work among the work exempt from the IRC permit requirement, and R105.2.2 lets ordinary repairs go without an application, unless they cut away part of a wall, cut structural members, change exits, or replace or move piping (downspout drain leaders included), wiring or mechanical work. Your city sets its own permit rules, so confirm with it.
An exemption is not a pass
The IRC says an exemption from a permit never allows work that breaks the code. Cities can also set their own permit rules; see roof permits by city and painting permits and HOAs.
Lead paint
In a home built before 1978, a federal EPA rule, not the IRC, may apply to paid work that disturbs paint. See lead paint in older Texas homes.
Primary Source
Where to read the code yourself
ICC publishes the IRC to read online, and your city posts the edition it adopted.
The code and your city
The International Code Council lets anyone read the IRC online without buying it. Start with your city’s building department page to see which edition and amendments it adopted, then read that edition. Section numbers can move between editions.
Common Questions
Questions homeowners ask
Does Texas have a building code for houses?
Inside city limits, yes. Texas Local Government Code Section 214.212 makes the International Residential Code the residential building code for cities, and each city may adopt a newer edition. Outside city limits, a county applies it only if it opts in, and then only to new houses and large additions.
Does the building code require gutters in Texas?
Not by name. Where expansive or collapsible soils are known to exist, IRC Section R801.3 requires a controlled way to carry roof water at least 5 feet from the foundation or to an approved drainage system. Gutters with downspouts are, on our reading, the usual way to meet it.
Do I need a permit to paint my house in Texas?
The IRC lists painting and similar finish work as exempt from its permit requirement (Section R105.2), but cities set their own permit rules, so confirm with your city and HOA. In a home built before 1978, the EPA lead rule may apply to paid work that disturbs paint.
What drywall does code require between a garage and a house?
At least 1/2 inch gypsum board, or equivalent, on the garage side between the garage and the house and its attic, and at least 5/8 inch Type X gypsum board, or equivalent, under rooms above the garage, under IRC Table R302.6.
Which IRC edition does my city use?
Around Round Rock, Round Rock, Austin and Hutto list the 2024 edition and Georgetown, Pflugerville, Cedar Park and Leander list 2021. Editions change by ordinance, so confirm on your city’s building department page.
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