START FROM THE SYMPTOM
Window Repair or Replacement — Which One Do You Need?
You arrived with one thing you can see or feel. This page routes from that, instead of asking you to read an argument for each outcome and work out which half you belong in.
- No obligation
- No payback figure invented
- We install nothing
Find the fault before you price it
Half the quotes people collect are for the wrong job. Naming the symptom accurately is what stops that.
If it is replacement →
Signs replacement may be needed
Six findings that usually take an opening past what a repair can hold.
Rot in the frame or sill
Timber that gives under a thumbnail has been taking water for a while, and how far it has gone cannot be established without opening the trim. This finding usually points at full-frame work rather than at a unit.
The opening has moved
A frame that has gone out of square no longer meets its sash anywhere along the closure, and no amount of hardware adjustment brings back a seal the geometry has lost.
The same faults, house-wide
One failing opening is about that opening. The same failure arriving across most elevations inside a single season is about age, and pricing them one at a time costs more than pricing them together.
Repairs that have not held
An opening already repaired twice for the same fault is telling you the fault is not where the repair was. The third repair is rarely the one that changes it.
The window has to change
A different operating type, a different size, or a requirement the existing unit cannot meet is a replacement by definition, whatever condition the old window is in.
Parts are no longer supplied
A window whose balances, seals or glazing units can still be bought is repairable. One whose cannot is on a clock, however sound it looks from the room.
None of them is about age. The usual way this gets answered is backwards: someone decides the windows are old, collects quotes for all of them, and finds afterwards that six were sound and two had a failed part. The reverse mistake is just as common — repairing one window three times because nobody looked at the sill under it.
The test, in four stages
Run it per opening rather than per house, and write down what you find before anyone visits.
Observe, per opening
Go round the house and write down what you can see and feel at each window. Two rooms legitimately produce two different answers.
Name the fault
Say what has failed rather than what you want done — a balance, a seal, weatherstripping, a sill. The name of the fault is what makes the next two steps possible.
Price the right job
Ask for the repair and the replacement of the same opening. A quote written for the wrong scope is not a comparison.
Decide per opening
A mixed answer is legitimate. Replacing some openings and servicing the rest is often the proportionate plan, and rarely the one a package proposes.
Ten symptoms and where each one points
Find the row that matches what you can see or feel, and start from there.
| What you can see or feel | What it tells you | Where it points |
|---|---|---|
| Haze or moisture between the panes | Moisture is inside the sealed cavity, so the seal around that glass unit is no longer keeping it out. | The sealed unit rather than the window. Whether it can be dealt with on its own depends on the specific window. |
| Condensation on the room-side surface in cold weather | ENERGY STAR describes this as water condensing when the inside surface falls below the dew point of humid indoor air, and says even certified windows can suffer from it in cold weather. | Indoor humidity and ventilation first. ENERGY STAR advises venting dryers and kitchen and bath fans directly outside and running them during and after showering or cooking. |
| A draft you can feel at the perimeter | Air is moving between the frame and the wall rather than through the window itself. | Sealing and insulation at the opening, which is installation work and not necessarily a new window. |
| A draft at the sash itself | The weatherstripping or the closure has stopped doing its job. | Repair first. Weatherstripping, locks and closure adjustment are replaceable parts on most windows. |
| A sash that will not stay up | The balance mechanism has failed. The window around it has not. | Ask whether the balance can be replaced on your window before anyone quotes you a new unit. |
| Soft, dark or crumbling timber in the sill or frame | Water has been getting into the frame for some time and the frame is no longer sound. | Replacement, and probably full-frame, because the opening has to be exposed and made good. |
| A cracked or broken pane in an otherwise sound window | One component has failed. Nothing else about the window has been tested by it. | Glazing work rather than replacement, unless that same window has other faults on this list. |
| Staining, swelling or peeling paint on the wall below | Water is reaching the wall. The window may or may not be the route it took. | An inspection of the opening before any unit is ordered. Replacing the window without finding the path leaves the path. |
| A window painted shut, or one that binds in its frame | Usually accumulated paint, swelling, or an opening that has moved. | Repair, unless the opening itself has gone out of square, which is a structural question. |
| Rattling, or a lock that no longer aligns | The sash has loosened in its track, or the frame has shifted around it. | Hardware and adjustment first. A frame that has genuinely shifted is a larger question than the lock. |
Where a row points at repair, that is a starting point rather than a conclusion — a window can carry more than one of these faults, and two or three together change the answer.
The condensation row is ENERGY STAR’s explanation and advice, read on 22 August 2026 from its residential windows, doors and skylights guidance. The remaining rows describe what a fault indicates and which question to ask about it; none of them is a diagnosis of your window, which nobody can make without seeing it.
The second row surprises people most
Water on the inside of the glass in winter is usually a message about the room, not about the window.
A great many replacement projects begin with condensation running down the inside of a pane on a cold morning. ENERGY STAR’s account of it is that water condenses on interior window surfaces when the surface temperature drops below the dew point of the humid air in the room, that certified windows are more resistant to it, and that even they can suffer from it in cold weather. Its advice is about the air: manage indoor humidity, vent dryers directly outside, make sure kitchen and bathroom fans vent outside rather than into the house, and keep them running after showering or cooking.
That does not make the window irrelevant — a colder inner surface condenses sooner, which the certified ratings describe. It means a new window is not a humidity control system. What those ratings measure is on energy-efficient windows.
When repair is the proportionate answer
The conditions under which repair is obviously right, and the ones under which it gets paid for twice.
Repair is proportionate when
- The fault is in a replaceable part: a balance, a lock, a hinge, a roller, weatherstripping.
- One pane or one sealed unit has failed in a window that is otherwise sound.
- The frame and sill are dry, square and structurally intact.
- The problem is confined to one or two openings rather than to every elevation.
- The window is part of what the house is, and a like-for-like replacement does not exist.
A repair is money spent twice when
- The sill under the new hardware is already soft, so the fault outlives the part that was changed.
- Water is reaching the wall and nobody has established the path it takes to get there.
- The same opening has been repaired for the same fault before, and the fault has come back.
- The parts the repair depends on are no longer supplied, so the fix is a postponement.
If the answer does come back as replacement for some or all of your openings, the project itself is sequenced on window replacement, and what happens on the day — and what to look at while an opening is still open — is on window installation.
If the fault is in the glass
Fogging between the panes is a failure of one component in a window that may be sound everywhere else, which is why it deserves its own conversation before it becomes a whole-house project. We publish no general rule about whether the glass alone can be changed, because the answer depends on how the unit is held and whether it is still supplied, and a general rule would be wrong in a large number of houses.
How sealed units fail →Is it worth the money?
Worth is a comparison, and not between a new window and nothing. It is between a new window and the repair you would otherwise carry out, over the period you expect to own the house. Three things decide it: how much of the repair bill recurs, whether the repair leaves an underlying cause in place, and what else the replacement buys that the repair does not.
Full cost guide →Questions to ask a contractor
Six questions that separate a company diagnosing your window from one quoting a catalog.
- Which part of this window has actually failed, and can that part be bought on its own?
- Can the sealed glass unit be dealt with without replacing the whole window?
- Is the sill under this opening sound, and how did you establish that?
- If this is replacement, is it an insert or full-frame, and why that one here?
- What would you do at this opening if the budget covered only half the house?
- What happens to your price if rot is found once the trim comes off?
Browse by state
All locations →Who repairs, who replaces and who will do either at one address changes with the ZIP code.
Common questions
Name the fault, then price the right job
A quote for the wrong scope is not a bargain and not a comparison. Start from the opening.