New build inspection · Plumbing
Plumbing defects in a new build
Plumbing defects in a new home are rarely dramatic leaks; they are missing shut-offs, unsupported pipe and drainage details that only reveal themselves after a season of use.
What goes wrong with plumbing in a new build?
Reviewed · 2026-09-03Plumbing defects in a new home are rarely dramatic leaks; they are missing shut-offs, unsupported pipe and drainage details that only reveal themselves after a season of use.
Why it matters
Plumbing in a new home
Plumbing is pressure tested before drywall, so outright leaks are usually caught. What survives to possession is the set of items a pressure test cannot detect: valves that were never installed, pipe that is inadequately supported, fixtures that drain slowly, and venting that was routed for convenience rather than correctly.
Most modern Calgary homes are plumbed in PEX rather than copper. It is a good material, but it needs support at intervals and protection where it passes through framing, and it is easy to run quickly and badly.
The Alberta-specific item is freezing. An exterior hose bib that is not frost-free, or is frost-free but installed without the required slope, holds water in the pipe over winter and splits inside the wall. The failure shows up the following spring, the first time the tap is opened.
Best moment to look
Pre-possession walkthrough
Run every fixture at the walkthrough, then check under every sink and around the water heater the following day for slow leaks that only appear with use.
In Alberta
Frozen and split hose bibs are one of the most common first-spring warranty calls in Calgary, and the damage happens inside the wall where it is not noticed until water appears in a basement ceiling. Before the first freeze, disconnect every garden hose, because a hose left attached defeats a frost-free bib entirely by trapping water in it. Plumbing and other distribution systems typically carry a shorter Alberta New Home Warranty period than the structure, so plumbing complaints are time sensitive.
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.
01Missing or inaccessible shut-off valves
Comfort and costWhat it is. Every fixture should have its own shut-off so a repair does not mean shutting down the house. Missing or buried valves turn a small failure into an emergency.
How to spot it. Look under each sink and behind each toilet for two valves and one respectively. Find the main shut-off and confirm you can reach and turn it.
Visible at: Pre-possession walkthrough
02PEX unsupported or unprotected through framing
Water and envelopeWhat it is. PEX needs support at intervals or it sags and moves, and it needs a nail plate where it passes through a stud so a future picture hook does not pierce it.
How to spot it. At pre-drywall, look at horizontal pipe runs for regular clips, and at every point pipe crosses a stud face for a steel protection plate.
Visible at: Pre-drywall
03Hose bibs not frost-free or wrongly sloped
Water and envelopeWhat it is. An exterior tap in Calgary must drain when closed. A standard bib, or a frost-free unit installed level or sloping back, holds water that freezes and splits the pipe inside the wall.
How to spot it. Ask which type is installed. From inside, look at the pipe where it exits the wall; a frost-free bib should pitch slightly downward toward the outside. Confirm no interior shut-off is left closed with the line full.
Visible at: Pre-possession walkthrough
04Slow drains and unvented fixtures
Comfort and costWhat it is. A fixture that gurgles or drains slowly in a brand new house usually indicates a venting problem or debris left in the line, not a temporary condition.
How to spot it. Fill each sink and tub and release it. Listen for gurgling from other fixtures, watch the speed, and check for water backing up elsewhere.
Visible at: Pre-possession walkthrough
05Water heater venting, relief valve or drain pan issues
SafetyWhat it is. A gas water heater needs correct venting and a temperature and pressure relief valve piped to a safe discharge point. Tank units in finished spaces should sit in a pan with a drain.
How to spot it. Look for the relief valve discharge pipe running down to near the floor rather than stopping in mid-air, and check that the vent is properly connected and sloped.
Visible at: Pre-possession walkthrough
06Leaks that only appear after use
Water and envelopeWhat it is. Compression fittings under sinks and appliance connections often weep rather than gush, and the trace can take a day to show. Nothing at the walkthrough does not mean nothing at all.
How to spot it. Run every fixture hard, then place a dry paper towel under each trap and connection and check it the next day.
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.
- Are the exterior hose bibs frost-free, and what is the winter shutdown procedure for this house?
- Where is the main water shut-off and is there a shut-off for the exterior taps?
- Is the water heater under a manufacturer warranty separate from the builder warranty?
- Was the system pressure tested, and is there a record?
FAQ
Questions about plumbing
Disconnect every hose in the fall, without exception. A frost-free hose bib drains by pitching water back into the heated part of the wall when you close it, and an attached hose blocks that drain path completely. If there is an interior shut-off for the exterior line, close it and then open the outside tap to let the line drain.
No. PEX is standard in new Alberta construction, handles freezing better than rigid copper, and has fewer joints. What matters is installation: adequate support so it does not sag, protection plates where it passes through framing, and correct fittings. Those are the things worth checking at pre-drywall.
In a brand new home there is nothing to clear. A slow or gurgling drain generally means a venting issue or construction debris in the line, and both are workmanship items. Report it in writing with the specific fixture named, and ask them to scope or vent-test rather than snake and hope.
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.