New build inspection · Garage and fire separation
Garage and fire separation defects in a new build
An attached garage has to be sealed and fire separated from the living space, and the details that do that work are among the most frequently incomplete items in a finished new home.
What goes wrong with garage and fire separation in a new build?
Reviewed · 2026-09-03An attached garage has to be sealed and fire separated from the living space, and the details that do that work are among the most frequently incomplete items in a finished new home.
Why it matters
Garage and fire separation in a new home
A garage stores vehicles, fuel and chemicals against the side of a house full of people. The building code responds by requiring the wall and ceiling between them to resist fire for a period, and to be sealed so exhaust fumes cannot migrate into the living space.
Both requirements are commonly compromised, and usually for mundane reasons. Drywall in the garage gets hung but never taped, because the garage is not a finished room and nobody thinks of the taping as structural. Penetrations for wires and pipes are left unsealed. The door into the house gets its self-closing hardware removed because it is annoying.
This is the single easiest inspection in the house. Everything is visible, at eye level, and takes ten minutes.
Best moment to look
Pre-possession walkthrough
Check the garage at the walkthrough, then check it again after any post-possession work, because a later basement development or shelving install often breaches the separation.
In Alberta
Carbon monoxide from a vehicle in an attached garage is a recognised hazard, and it is the reason both the sealing requirement and the carbon monoxide alarm requirement exist. Two Calgary-specific habits make it worse: block heaters and remote starters mean vehicles idle in garages on cold mornings, and heavy snow load on vehicles means constant meltwater at the common wall. Check the garage separation before your first winter, and confirm there is a working carbon monoxide alarm on the house side of the wall.
How it should be built
What correct looks like
Fire and gas separation at an attached garage
The shared wall and ceiling are taped and sealed, penetrations are filled, the door self-closes, and a carbon monoxide alarm sits on the house side.
The flags
What to look for
Each item lists what the defect is, how to spot it without tools, and the stage of construction when it is still visible. None of this replaces a licensed inspector. It makes you a useful witness on your own site.
01Drywall untaped or unsealed at joints
SafetyWhat it is. Fire separation depends on a continuous membrane. Drywall hung and left with open joints, or with gaps at the top plate and the floor, does not provide the rated separation.
How to spot it. Look at every drywall joint on the common wall and ceiling, including the corners and up where the wall meets the ceiling. Joints should be taped and filled, not open.
Visible at: Pre-possession walkthrough
02Penetrations not sealed
SafetyWhat it is. Every wire, pipe, duct and bolt through the common wall is a path for smoke and carbon monoxide. These are supposed to be sealed with an appropriate material.
How to spot it. Look for holes around electrical boxes, hose bib pipes, dryer ducts and anything else passing through the shared wall or ceiling. Gaps you can see light or daylight through are the finding.
Visible at: Pre-possession walkthrough
03Missing self-closing device on the house door
SafetyWhat it is. The door between the garage and the house is generally required to be self-closing so it is never left standing open. The hardware is often omitted or removed.
How to spot it. Open the door into the house and let go. It should close on its own and latch. If it stays open, the device is missing or disabled.
Visible at: Pre-possession walkthrough
04Attic access located in the garage without separation
SafetyWhat it is. A hatch in the garage ceiling that opens into the same attic as the house breaks the separation entirely, giving smoke a direct route into the roof space above the bedrooms.
How to spot it. Look for an attic hatch in the garage ceiling. If there is one, ask how the separation is maintained and whether the hatch itself is rated and sealed.
Visible at: Pre-possession walkthrough
05Garage slab sloped toward the house
Water and envelopeWhat it is. The garage floor should fall toward the overhead door so melting snow, which in Calgary arrives on every vehicle all winter, drains outward rather than pooling at the common wall.
How to spot it. Pour water at the back of the garage and watch where it goes. Look for staining or salt residue along the wall shared with the house.
Visible at: Pre-possession walkthrough
06Overhead door safety features not working
SafetyWhat it is. A powered overhead door needs functioning photo eye sensors and an auto-reverse. These get knocked out of alignment during construction and are rarely retested.
How to spot it. With the door closing, break the photo eye beam with an object. The door should stop and reverse. Test the reverse on contact as well, using a block rather than a person.
Visible at: Pre-possession walkthrough
Put it in writing
Questions for the builder
Ask these by email rather than on site. A written answer is a record, and a builder who answers clearly in writing is telling you something useful about how the rest of the build will go.
- Is the garage drywall taped and sealed as fire separation, and were penetrations sealed?
- Is the door into the house self-closing, and is that hardware included?
- Is there a carbon monoxide alarm on the house side of the garage wall?
- Does the garage slab slope to the overhead door?
FAQ
Questions about garage and fire separation
Where the drywall is acting as fire separation between the garage and the living space, the assembly only performs as rated if it is continuous, which means joints are taped and filled and penetrations are sealed. Untaped garage drywall is one of the most commonly reported new build findings, partly because it looks like an unfinished cosmetic detail rather than a safety one.
Because the separation only works when the door is shut, and in practice people prop that door open while carrying groceries or leave it ajar. A self-closing device means the separation restores itself. If yours does not close and latch on its own, ask for the hardware to be installed rather than removing the question.
If you have an attached garage, yes. A vehicle running for even a short time in an attached garage can push carbon monoxide into the house through gaps in the separation, which is exactly the scenario the alarm requirement addresses. Confirm the alarm is on the house side, near the sleeping areas, and that it is within its service life.
Source note
- Sources
- Alberta New Home Warranty program information
- National Building Code, Alberta Edition, as adopted for the permit in force
- City of Calgary building inspection and lot grading information
- Health Canada radon guidance for homeowners
- Jurisdiction
- Alberta, with Calgary-specific notes
- Applies to
- New residential construction purchased from a builder.
- Last reviewed
- 2026-09-03
- Limitations
- General guidance written for buyers, not a code interpretation and not a substitute for a licensed home inspector or a professional engineer. Code requirements depend on the edition in force when the permit was issued. Warranty periods and coverage depend on your own warranty certificate.
- What you should verify
- The requirements that applied to your permit, the coverage periods on your warranty certificate, and any defect with a licensed inspector before you rely on it in a claim.
Work with REP YYC
Bring your own representative to the walkthrough.
The builder's sales staff are paid to sell the builder's lots. REP YYC agents are paid by the builder too, but they work for you: lot choice, contract terms, incentives and the possession timeline. No cost to the buyer.