New build inspection · Electrical
Electrical defects in a new build
Electrical defects in new homes cluster around protection devices and labelling rather than wiring itself, and most of them can be found with a cheap outlet tester and half an hour.
What goes wrong with electrical in a new build?
Reviewed · 2026-09-03Electrical defects in new homes cluster around protection devices and labelling rather than wiring itself, and most of them can be found with a cheap outlet tester and half an hour.
Why it matters
Electrical in a new home
Rough-in electrical is inspected before drywall and again at final, so gross wiring errors are usually caught. What tends to survive is a set of quieter problems: protection devices that were specified but not installed, a panel directory that says nothing useful, receptacles wired with reversed polarity, and alarms placed where they will not do their job.
Two device types matter most. Ground fault protection cuts power when current leaks to ground, and belongs anywhere water and electricity meet. Arc fault protection detects the signature of an arcing connection, which is a leading cause of residential fire, and modern codes require it across most living areas.
None of this requires an electrician to check at a basic level. A plug-in outlet tester costs very little and will find reversed polarity, open grounds and missing ground fault protection in every receptacle in the house.
Best moment to look
Pre-possession walkthrough
Test every receptacle, every switch and every alarm at the walkthrough. This is one of the few systems you can check completely in an hour.
In Alberta
Electrical work in Alberta is permitted and inspected, and a final electrical inspection is required before occupancy. That inspection is a genuine safeguard, but inspectors sample rather than test every device in the house, which is why buyers still find reversed receptacles and unlabelled panels. If you are planning an electric vehicle charger, a hot tub, a garage heater or a future basement suite, ask now whether the panel has physical space and capacity, because adding it later is far cheaper if the rough-in exists.
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 ground fault protection at wet locations
SafetyWhat it is. Receptacles near sinks, in bathrooms, in the garage, outdoors and in unfinished basements need ground fault protection. It is occasionally omitted, or one device is expected to protect a circuit it does not actually cover.
How to spot it. Use a plug-in tester with a test button at every wet-location receptacle. The power should cut. If nothing happens, the protection is not there or not covering that outlet.
Visible at: Pre-possession walkthrough
02Missing arc fault protection on living area circuits
SafetyWhat it is. Arc fault breakers detect arcing faults in wiring and are required by current codes over most of the living space. Substituting a standard breaker is invisible unless you open the panel.
How to spot it. Open the panel cover door and look at the breakers. Arc fault breakers are physically distinct and carry a test button. Ask which circuits are protected.
Visible at: Pre-possession walkthrough
03Panel directory blank, generic or wrong
SafetyWhat it is. A panel labelled "bedroom, bedroom, kitchen" is nearly useless in an emergency. Directories are commonly filled in from the plan rather than by testing what each breaker actually controls.
How to spot it. Pick three breakers, switch them off, and check what actually loses power against what the label claims.
Visible at: Pre-possession walkthrough
04Reversed polarity and open grounds
SafetyWhat it is. A receptacle wired with hot and neutral reversed, or with no ground connection, will run an appliance normally and still be a shock hazard.
How to spot it. A plug-in outlet tester shows both conditions immediately with a light pattern. Test every receptacle in the house, including the ones behind furniture and in closets.
Visible at: Pre-possession walkthrough
05Smoke and carbon monoxide alarms missing, misplaced or unlinked
SafetyWhat it is. Alarms are required on every level and near sleeping areas, and in new construction they are generally required to be interconnected so all sound together. Placement too close to a kitchen or a bathroom causes nuisance alarms that lead owners to disable them.
How to spot it. Count the alarms on every floor and outside each sleeping area. Press test on one and confirm the others sound. Confirm carbon monoxide coverage where there are fuel-burning appliances or an attached garage.
Visible at: Pre-possession walkthrough
06Junction boxes buried or left without covers
SafetyWhat it is. Every splice must be in an accessible box with a cover. Boxes buried in insulation, closed into a wall or left open are a fire risk and a code violation.
How to spot it. In the attic, the basement and the garage, look for boxes with no cover plate or wires joined outside a box. At pre-drywall, note the location of every box and check they remain accessible.
Visible at: Pre-drywall
07Exterior receptacles without weather-resistant covers
SafetyWhat it is. Outdoor receptacles need covers that keep water out while a cord is plugged in, not just when closed.
How to spot it. Look at each exterior receptacle. The cover should be the bubble type that closes over a plugged-in cord.
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.
- Which circuits have arc fault protection, and which receptacles have ground fault protection?
- Was the panel directory filled in by testing each circuit?
- Is there panel capacity and physical space for an EV charger, a hot tub or a future suite?
- Are the smoke and carbon monoxide alarms interconnected, and are they hard-wired?
FAQ
Questions about electrical
Ground fault protection watches for current leaking to ground, which is what happens when electricity finds a person or water, and it protects against shock. Arc fault protection watches for the electrical signature of an arcing connection, such as a damaged wire or a loose terminal, and it protects against fire. New homes need both, in different places, and they are not interchangeable.
The basics, yes. A plug-in outlet tester is inexpensive and will find reversed polarity, open grounds and missing ground fault protection across the whole house in under an hour. You can also count alarms, test them, and verify the panel directory by switching breakers. Anything inside the panel beyond reading labels belongs to a licensed electrician.
If there is any chance you will want one, yes, and ask before drywall. A conduit run from the panel to the garage wall and reserved panel capacity costs a fraction of retrofitting later, when the wall is finished and the panel may be full. Ask specifically about available capacity, not just whether a wire can be run.
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.