It's mid-January, -24°C outside, and you hear a sharp crack from the stairwell at 2 a.m. In the morning there's a hairline crack above a doorway, a few round bumps in the drywall, and a film of water on the bottom of the bedroom windows. Did the builder cut corners, or is your new house just going through its first winter?
Usually it's the second. A new wood-frame home is built with lumber that still holds moisture, and the first heating season dries it out fast. Framing shrinks, joints move and the drywall shows it. At the same time a modern, airtight envelope traps every litre of water you produce by cooking, showering and breathing. Some of what you see in year one is normal. Some of it should go on your warranty form before the deadline. This guide puts the two side by side.
Normal settling vs. warranty issue at a glance
| Symptom | Usually normal in year one | Report it when | Who acts |
|---|---|---|---|
| Drywall cracks and nail pops | Hairline cracks at corners, doors and windows; small screw or nail pops | Cracks wider than a few millimetres, growing, or with doors that stop closing | Note it, report at year end |
| Window condensation | Light fog on the bottom of the glass on the coldest nights | Water between panes, frost inside the frame, wet sills that stay wet | You first (humidity, HRV), then builder |
| Indoor humidity | High in the first months as materials dry | Mould, wet attic insulation, frost on nails in the attic | You adjust; builder if the envelope leaks |
| HRV | Needs seasonal adjustment and filter cleaning | No airflow, ice in ducts, constant defrost, rattling or no balancing report | You maintain; installer or builder fixes |
| Floors, doors, trim | Minor squeaks, gaps at trim and baseboards | Sloping floors, doors binding badly, tile cracking | Builder |
| Basement and foundation | Fine shrinkage cracks in poured concrete, dry | Water coming through, cracks that widen or leak | Builder, quickly |
| Seasonal maintenance | Always your job | Never covered if damage comes from skipped upkeep | You |
Warranty programs differ by province. Ontario has Tarion, Quebec has the Garantie de construction résidentielle, British Columbia's coverage is overseen by BC Housing's licensing and consumer services branch, and Alberta has its own new home warranty legislation. Coverage is usually split into a short period for workmanship and materials, a longer one for things like the building envelope, and a long one for structure. Forms and deadlines matter more than anything else: check your own program's guidelines and calendar the dates the week you get the keys.
Drywall cracks and nail pops
Verdict: mostly normal, document and report together at the end of year one.
Framing lumber can shrink noticeably across its width as it dries over the first heating season, and floor joists and top plates move the most. Drywall is rigid, so it cracks at its weak points: corners of door and window openings, the joint between wall and ceiling, and stairwells. Nail and screw pops are fasteners pushed out as the wood around them moves. In a four-bedroom, two-storey Craftsman of 3672 sq ft you'll often see more of this on the upper floor and along the open stair, simply because there's more stacked lumber shrinking under it.
Don't patch every crack in February. Movement continues until the house has been through a full cycle of seasons. Photograph each one with a date, keep a list, and let the builder repair them once, typically near the end of the first year, if your program covers drywall shrinkage. A crack that keeps widening, or a door that suddenly won't latch, is a different story: report that right away.
Window condensation
Verdict: light condensation is a humidity signal, not a defect; water between the panes is a defect.
The glass is the coldest surface in the room. When warm, moist air touches it at -20°C outside, water condenses on the lower edge of the pane, where the glass is coldest near the spacer. Airtight houses show this more than drafty old ones, especially in the first winter when concrete, lumber and drywall are still giving off moisture.
Homes with lots of glass need the most care. A one-storey modern mountain ranch of 4167 sq ft with tall windows, or the large-window plans in general, will fog up first, and blinds or heavy curtains pulled tight make it worse by keeping warm air off the glass. Open window coverings during the day, keep the heating registers under windows clear, and lower the humidity before you blame the windows. Fogging inside a sealed unit, frost forming on the frame itself, or a sill that rots or stains is a warranty matter.
Indoor humidity: setting it for the outdoor temperature
Verdict: you control this one, and the right number drops as it gets colder.
Comfort guides often quote 40 to 50% relative humidity, but in a Canadian winter that's too high for most windows. The common rule, used on many humidistat dials, is to lower the indoor target as the outdoor temperature falls. Treat these as starting points and adjust to what your windows tell you:
| Outdoor temperature | Indoor relative humidity to aim for |
|---|---|
| Around -10°C | About 30 to 35% |
| Around -15°C to -20°C | About 25 to 30% |
| Around -25°C | About 20 to 25% |
| -30°C and colder | About 15 to 20% |
A digital hygrometer costs roughly $15 to $40 in 2026 and is the most useful tool you'll buy for the house. Put one in the main living area and one in a bedroom. In year one, most new homes don't need a humidifier at all; many need help getting rid of moisture instead. If your furnace has a humidifier, leave it off for the first winter unless the reading is consistently below the target.
HRV settings
Verdict: the HRV is your main humidity control, so learn its settings rather than turning it off.
Codes across Canada now expect mechanical ventilation in new homes, and in most of them that means a heat recovery ventilator (or an ERV in some designs). It swaps stale, moist indoor air for fresh, dry outdoor air while recovering much of the heat. In a cold snap, that outdoor air is very dry, so the HRV is how you pull humidity down.
- Condensation on windows: raise the HRV speed or run it continuously on low, and use the bathroom and kitchen exhaust longer after showers and cooking.
- Air too dry, static shocks, cracking trim: drop to a lower speed or intermittent mode, but keep it running.
- Defrost: at very low temperatures the unit cycles into defrost. That's normal. Ice building up in the ducts or a unit that never leaves defrost is not.
- Balancing: ask the builder for the balancing report showing supply and exhaust airflow. An unbalanced system can pressurize the house and push moist air into walls and the attic.
Clean the HRV filters every one to three months in winter and wash the core as the manual recommends. A unit that's set up correctly but still can't keep the windows clear points to a design or installation issue the builder should look at.
Floors, doors and trim
Verdict: small squeaks and gaps are normal; slopes and binding are not.
As subfloors and joists dry, you'll hear new squeaks and see gaps open at baseboards and casings. Hardwood shrinks too, so seams between boards get wider in the driest months and close again in summer. A door that rubs a little in January may be fine by May. Report doors that won't close at all, floors you can see slope, or tile and grout cracking in a line, because those can point to framing or support problems.
Basement and foundation
Verdict: dry hairline cracks are common; any water is urgent.
Full basements are standard in most of Canada because footings have to sit below the frost line, and poured concrete shrinks as it cures. Thin vertical cracks in the walls or the slab, dry to the touch, are typical. Mark the ends with a pencil and date them so you can tell if they grow. Water coming through a crack, efflorescence spreading across the wall, or a crack you can slide a coin into should be reported in writing right away, not saved for the year-end list.
Bungalows on full basements, such as a compact 1556 sq ft one-storey with five bedrooms or a 1758 sq ft Craftsman bungalow with a finished lower level, put a lot of the living space below grade. That makes the sump pump, the grading and the downspouts part of the living room, not just the mechanical room. You can browse more house plans with a basement to see how bedrooms and family rooms are laid out downstairs.
Fall and winter maintenance: always on you
Verdict: skipped maintenance can void warranty coverage, so treat this list as part of owning the house.
- Furnace and HRV filters: replace or clean before heating season and check monthly in winter.
- Sump pump test: in October, pour a bucket of water into the pit and confirm the pump starts and drains to the outside. Check the discharge line isn't buried or frozen. Consider a battery backup if your area loses power in storms.
- Eavestroughs and downspouts: clear leaves after they fall, make sure extensions carry water a couple of metres away from the foundation, and watch for ice dams after the first big thaw.
- Grading: new lots settle. Fill low spots against the foundation in fall so spring melt runs away from the house.
- Hose bibs: disconnect hoses, close the interior shut-off valve if you have one and drain the line. Even frost-free bibs can split if a hose is left attached.
- Snow around vents: after every storm, clear the HRV intake and exhaust hoods, the furnace and water heater vents and the dryer vent. A blocked high-efficiency furnace vent can shut down the heat or create a safety risk.
- Smoke and CO alarms: test them when you turn on the heat.
- Warranty log: keep your list of cracks, photos and dates in one place so the year-end form takes an evening, not a weekend.
A four-bedroom, 1669 sq ft one-storey with a basement has a short roofline and fewer eavestroughs to clear than a 5013 sq ft three-storey farmhouse, where reaching the upper gutters and the vent hoods safely may mean hiring help. It's worth thinking about while you're still choosing among one-storey plans and taller homes.
Who should choose what
- Hairline drywall cracks, small nail pops, light squeaks: document them and choose the year-end warranty claim, not a DIY patch in winter.
- Fog on the glass on cold nights: choose to adjust humidity and the HRV first, using the temperature table above.
- Water between panes, frost on frames, wet attic insulation: choose a written warranty report now.
- Any water in the basement or a widening foundation crack: choose to report immediately and keep the sump pump running.
- Dry air and static in a deep freeze: choose a lower HRV speed before adding a humidifier.
- Filters, sump tests, eavestroughs, vents and hose bibs: choose the checklist every fall, because no warranty covers damage from skipping it.
- Unsure where your problem falls: choose to ask your provincial warranty program or a home inspector before the deadline passes.
