Every year, the first real cold snap brings the same question: "Why are my windows dripping?" Before I became a REALTOR®, I spent years as a home inspector, and wet or frosted windows were one of the most common things I saw once winter settled in. The good news is that in most homes, the fix costs next to nothing.

Why it happens

Warm indoor air holds moisture. When that air touches something cold, like a window pane on a -20°C morning, it cools down and can't hold as much water, so the extra moisture lands on the glass. The colder it gets outside, the colder the glass gets, and the less humidity your home can carry before you see water or frost.

That's why the same house can be perfectly dry in October and dripping in January. The windows didn't change. The weather did.

Step one: measure, don't guess

Pick up a hygrometer. It's a small, inexpensive humidity reader sold at most hardware stores, and it takes the guesswork out. Put one in the main living area and check it first thing in the morning, when condensation is usually at its worst.

CMHC's rule of thumb is to keep indoor relative humidity between 30 and 50 per cent during the heating season, and around 30 per cent once it's colder than -10°C outside. CMHC also notes that in very cold weather, 30 per cent or lower may be needed to keep windows clear, and that newer, energy-efficient windows can handle higher humidity without condensing.

The simple fixes

Start with the free stuff. Health Canada's guidance on moisture and mould lists most of these, and they match what I'd tell clients at the end of an inspection.

• Use your fans. Run the bathroom exhaust fan during and after showers, and the range hood when you cook. If your fan doesn't seem to pull much air, hold a square of toilet paper up to the grille. If it doesn't stick, the fan or its duct needs a look.

• Open the coverings. Heavy curtains and blinds trap cold, damp air against the glass. Open them during the day, and leave a gap at night on the worst windows.

• Let the heat reach the glass. Keep furniture away from heat registers and baseboard heaters, and leave interior doors open so air can move.

• Wipe the sills. On the bad mornings, dry the frames and sills. Standing water is what turns into peeling paint, swollen trim and mould.

• Check your furnace humidifier. This is the big one I used to find. Many homes have a humidifier on the furnace with the dial set once and never touched again. Turn it down as the temperature drops, or off during a cold snap, and turn it back up when it warms.

• Watch other moisture sources. Lots of plants, drying laundry indoors, an aquarium or a damp basement all add up.

If you have a heat recovery ventilator (HRV), make sure it's running and that its filters are clean. It's designed to swap stale, humid indoor air for fresh outdoor air without losing much heat.

When it's the window, not the humidity

If your humidity reads around 30 per cent on a cold morning and you still have water on the middle of the glass, the windows themselves may be at their limit. And if you see fog or moisture between the panes of a sealed unit, that's a failed seal. Wiping won't help, and lowering humidity won't fix it. The sealed unit needs replacing, though often not the whole frame.

Frost on the frame that keeps coming back can also point to air leaking in around the window. Fresh caulking or weatherstripping is a cheap fix that can help with both comfort and your heating bill.

Why it matters if you're buying or selling

When I inspected homes, stained sills, peeling paint under windows and dark spots in the corners of window frames told me a story about how the house had been run in winter. Buyers and their inspectors notice the same things. If you're planning to sell in the spring, getting condensation under control now can save you repairs later, and it's one less thing to explain.

The short version

• Buy a hygrometer and aim for about 30 per cent when it's colder than -10°C outside, and lower still in a deep cold snap

• Run your fans, open the blinds, and keep vents clear

• Turn the furnace humidifier down during cold snaps

• Fog between the panes means a failed seal

Whether you're in Sunterra Ridge or anywhere else in Cochrane, a few small habits make a big difference to how your home comes through the winter. If you're thinking about a move and want to talk through what to look for in a home, we're always happy to help. Our neighbourhood guide and Sunterra Ridge page are good places to start.

Wayne & Sean Burton, REMAX West Real Estate

Sources: CMHC, Measuring Humidity in Your Home and Moisture and Air; Health Canada, Guide to addressing moisture and mould indoors.

Before I became a REALTOR®, I spent years as a home inspector. I could tell you a lot about a house from a walkthrough: how the roof was aging, whether the furnace had been looked after, where water was finding its way in. Radon was the exception. You can't see it, smell it or taste it, and nothing about a home's age, style or neighbourhood tells you whether it has a problem. The only way to know is to test.

The good news is that testing is simple, and right now is the best time of year to do it.

What radon is

Radon is a radioactive gas that forms naturally when uranium in soil and rock breaks down. Outdoors it disperses harmlessly. Indoors it can build up, entering through cracks in foundations, gaps around pipes, sump pits and floor drains. Health Canada calls radon the number one cause of lung cancer for non-smokers, which is why it's worth taking seriously even though it's easy to forget about.

Any home can have elevated radon: new or old, with or without a basement, in town or on an acreage. Two houses side by side can test very differently.

Why fall and winter are the best time to test

Health Canada recommends a long-term test lasting at least 91 days, or about three months, and says at least 91 days of the test should fall in the heating season. Its measurement guide describes October through April as the ideal window.

The reason is simple. In winter our windows and doors stay closed, and warm air rising through the house creates a slight draw at the foundation (the stack effect) that pulls more soil gas inside. Indoor radon levels are usually highest in the colder months, so a winter test gives you a conservative, realistic read on your yearly average. A test done in summer, with the windows open, risks underestimating it.

Start a test in early November and you'll have your results by spring.

How to test your home

1. Get a long-term test kit. Long-term detectors are small and easy to use, and you mail them to a lab when the test is done. Health Canada advises against relying on short tests of a few days to decide whether to fix anything, because radon levels swing from day to day.

2. Pick the right spot. Place the detector in the lowest lived-in level of the home, the area where someone spends a good part of the day, such as a finished basement, rec room or main-floor bedroom. Keep it away from drafts, heat sources, kitchens and bathrooms, and follow the kit's height and placement instructions.

3. Record the start date and leave it alone. Live normally. You don't need to change how you use the house during the test.

4. Mail it in after three months or more. Health Canada says results usually arrive within three to six weeks.

What your result means

The Canadian guideline is 200 becquerels per cubic metre (Bq/m³), based on your average annual level.

• Below 200 Bq/m³: no action is needed under the guideline. Health Canada notes there's no level that's completely risk-free, so the rest is your call.

• Above 200 Bq/m³: Health Canada recommends lowering it within one year.

• Well above 200 Bq/m³: act sooner. The higher the number, the faster you should fix it.

What fixing it looks like

High radon is a very solvable problem. The most common fix is a sub-slab depressurization system: a pipe through the basement floor and a small fan that draws radon from beneath the slab and vents it outside. Sealing cracks and openings helps, but usually doesn't solve it on its own. Use a certified radon mitigation professional, and test again afterwards to confirm the level has come down.

Radon and buying or selling a home

Radon comes up more and more in real estate. A few practical notes from both sides of the table:

• Sellers: a completed long-term test result, plus any mitigation receipts, is useful paperwork to have ready for buyers.

• Buyers: a long-term test can't be done in the few days before an offer's conditions come off. If you want peace of mind, plan to test once you've moved in, and know that mitigation is a known, manageable fix.

• Everyone: a short-term test can flag a concern, but Health Canada recommends basing decisions on a test of at least 91 days.

The bottom line

Radon testing is one of the cheapest, easiest things you can do for your home's long-term health, and the coming months are the right time to do it. Set the detector out in November, mark your calendar for February, and you'll know where you stand.

Have a question about radon, or anything else you've noticed in your home? Send us a message. We're happy to help, no strings attached.

Wayne & Sean Burton, REMAX West Real Estate, Cochrane, Alberta

Sources: Health Canada, Radon guideline; Guide for radon measurements in homes; Long-term test instructions; Should I test for radon?