What to Check on the Windows Before You Buy a BC Home
You’ve got twenty minutes at a showing, or maybe an hour with a home inspector who’s also checking the roof, the electrical panel, the crawlspace, and everything else. Windows rarely get more than a glance. But they’re one of the few building components you can actually assess yourself, on the spot, without any tools or training, and what you find can shift a negotiation by thousands of dollars.
After 35+ years manufacturing windows in Delta, BC, we get calls fairly often from people who just closed on a home and are now facing a window problem nobody flagged before they signed. Most of it was visible if someone had known what to look for. This is what to actually check.
Start With a Quick Fog Test
Stand close to a window and look at the glass edge-on, at an angle, rather than straight through it. Fogging or a hazy band trapped between the panes means a failed seal on a double or triple-pane unit. This is different from surface condensation, which wipes away and comes and goes with weather. Seal failure is permanent and doesn’t clear.
It’s easiest to spot on a cool morning or after the heat’s been off for a while, since that’s when the temperature differential makes any trapped moisture most visible. Check a few windows on different exposures, not just one, since seal failure often shows up first on south and west-facing glass that takes the most sun and heat cycling.
If you find it, the fix is glass unit replacement (if the frame is otherwise sound) or full window replacement, and either way it’s a real cost, not a wipe-and-forget issue.
Check Whether You’re Looking at Single, Double, or Triple Pane
This matters more than most buyers realize, and it’s easy to check without any tools. Look at the glass edge where it meets the frame, or knock lightly on the glass, single-pane has a slightly different sound and reflects light as one surface. If the home still has original single-pane glass, that’s usually a strong signal the windows are original to the house and decades old, regardless of what the listing says.
Another trick: hold a lit lighter or your phone flashlight near the glass at night and count the reflections. One reflection means single pane. Two means double. Three means triple. It’s not perfectly precise but it’s a fast way to confirm what you’re dealing with before you ask anyone.
Look at the Frame Material and Condition
Wood frames should be checked for soft spots, especially at the bottom corners and sill where water collects. Press a fingernail or a key into the wood at these points. If it dents easily or feels spongy, there’s rot underneath, even if the paint looks fine on the surface.
Aluminum frames, common in 1970s to 1990s Metro Vancouver homes, conduct cold directly and often show visible condensation streaking on the interior frame itself, not just the glass, during winter months. That streaking is a sign of poor thermal performance, not necessarily damage, but it tells you the windows are original and dated.
Vinyl frames should be checked for yellowing, chalking (a powdery residue when you run a finger across the surface), and warping. Slight yellowing on older white vinyl is cosmetic. Visible warping or bowing, especially on south-facing exposures, suggests the frames are failing structurally, not just aging in appearance.
Test the Operation
Open and close a few windows in different rooms, not just the one nearest the front door. Windows that stick, require real force, or won’t stay open on their own often have swollen frames, failed balances, or track debris. This can be a minor fix or a sign of moisture-related swelling that goes deeper than the hardware.
Check the locks too. If they engage smoothly and the sash pulls tight against the frame, that’s a reasonable sign the window is sealing properly. Loose, wobbly, or hard-to-engage locks usually mean worn hardware and reduced airtightness, even if the glass itself looks fine.
Check for Water Staining Around the Frame
Look at the drywall, trim, and sill area around each window, inside and out if you can. Staining, bubbling paint, or a slightly soft feel to the drywall below a window is one of the most reliable signs of a leak that’s been happening for a while, even if it’s not actively wet the day you look.
This is worth taking seriously. A leaking window that’s been ignored can mean rot in the framing behind the wall, not just a window problem. If you see staining, it’s worth asking directly whether the seller is aware of it and whether any repair was done, and getting that in writing where possible.
Ask About Permits, Especially If Windows Look New
If the home has windows that look clearly newer than the house itself, ask the listing agent or seller directly whether a permit was pulled for the work, particularly if any window openings look like they were resized or if the replacement was recent. Unpermitted work discovered after a sale can become the buyer’s problem, not the seller’s, once you own the home. It can complicate future insurance claims and create issues if you ever want to sell.
Most straightforward like-for-like replacements don’t require a permit in Metro Vancouver, so this isn’t usually a red flag on its own. But if the windows were resized, added, or if the home is in a heritage designation area, it’s worth a direct question before you remove subjects.
Weigh What You’re Seeing Against the Home’s Age
A quick mental framework helps here. Vinyl windows generally last 20 to 40 years depending on quality and exposure, with hardware and seals often needing attention well before the frame itself fails. If a home was built or last had windows replaced more than 20 years ago, budget mentally for replacement within the next several years even if everything looks functional today. The 20-year mark is often when the real decision point arrives, whether the current owner already dealt with that or it’s about to land on you.
A home with original 1980s aluminum sliders is a very different proposition than one with vinyl windows replaced five years ago, even if both show fine on a walkthrough. Ask when the windows were last replaced. Sellers and agents usually know, or can find out, and it’s a completely normal question to ask.
Turning What You Find Into Negotiating Leverage
None of this needs to be a dealbreaker. Most homes have windows somewhere between perfect and terrible, and window condition is one of the more straightforward things to price into an offer or a post-inspection negotiation, because the cost to fix it is fairly well understood.
If you’re finding multiple fogged units, visible rot, or windows clearly original to a decades-old home, get a realistic sense of replacement cost before you finalize your offer. A whole-home replacement in Metro Vancouver typically runs $12,000 to $25,000 depending on window count, style, and glazing, and having that number in hand gives you something concrete to raise in negotiation, whether that’s a price adjustment, a credit, or simply going in with eyes open about what you’re taking on.
If You’ve Already Bought the Home
If you’re past closing and now looking at windows you wish you’d caught earlier, that’s a common enough situation and not one worth losing sleep over. Quality window replacement pays back through energy savings, comfort, and resale value whether you do it in year one of ownership or year ten. There’s no penalty for catching it after the fact rather than before.
Contact us for an honest assessment of what you’re working with. We’ll tell you what’s cosmetic, what’s worth watching, and what actually needs attention now, and give you a realistic sense of cost and timeline whether you’re planning to act right away or just want to know what you’re dealing with.
What to check on the windows before buying a home in BC: spotting fogged seals, rot, single vs double pane, and permit red flags during a showing or inspection. Local Metro Vancouver manufacturer guidance.
