A uPVC window lock that won't lock, won't turn, or has a handle that spins is a security problem — but it's usually a cheap one to fix. Here's what the different faults cost, what you can sort yourself, and when to call someone in.
What kind of lock does a uPVC window have?
Most uPVC windows use an espag lock — a flat metal strip along the edge of the sash that throws locking points into the frame when you turn the handle. Over time the handle, the spindle, or the mechanism itself wears out, and the window stops securing.
What uPVC window lock repair costs
Prices are typical UK figures, not a quote.
| Fix | Typical price |
|---|---|
| Lock adjustment / re-alignment | from £75 |
| Handle replacement | from £85 |
| Locking mechanism (espag) replacement | from £115 |
| Full lock overhaul, flat-rate per window | around £175 |
What moves the price:
- Which part failed — a handle is cheaper than the full mechanism.
- The window's make — some brands have pricier or harder-to-source parts.
- Access — an upstairs window takes longer to work on safely.
Can you fix it yourself?
- A loose handle is often just loose screws — tighten them first.
- A stiff handle often responds to lubricating the locking points and mechanism.
- A handle replacement is DIY-able if you match the exact make and backplate size.
But if the handle turns and nothing engages, or the key won't turn, the mechanism itself has failed. That's specific to the window's make and usually needs a professional with the right part — and it's a security issue you don't want to get wrong.
When to call a professional
Call someone in if the window won't lock, the handle spins freely, or you can't match the part. Leaving a window unlocked because the lock's broken is a bigger risk than the cost of fixing it.
Get a fixed quote — tell us the fault and the window's make if you know it.
