Help & Advice

uPVC Door & Window Help

Free guides to measuring, fixing and choosing uPVC door and window hardware: euro cylinders, multipoint locks, handles, letterboxes, hinges, window mechanisms and draught seals. Written by the Home Secure team at our trade counter in Aintree, Liverpool.

What's the problem?

Tap the one that sounds like yours and go straight to the fix.

Measure or identify your part

Get the size right first time. These are the guides our customers use most before ordering.

What do you need to do?

Measure & identify

Find the exact part before you order.

Fix a problem

Find the cause first, then fix it.

Choose what to buy

Our honest picks, and why.

Fit it yourself

Step-by-step, with a screwdriver.

Browse guides by area

Every guide, grouped by the part of the home it's about.

Door Locks & Keys

Measure, fix and choose euro cylinders, multipoint locks, keypad locks and keys.

All 26 Door Locks & Keys guides
Door Locks & Keys guides Shop door locks

Door Handles, Letterboxes & Hinges

Identify, measure and replace uPVC door handles, letterboxes, hinges, latches and spindles.

All 15 Door Handles, Letterboxes & Hinges guides
Door Handles, Letterboxes & Hinges guides Shop door hardware

Windows

Window handles, espag mechanisms, friction hinges and restrictors: identify, measure and fit.

All 10 Windows guides
Windows guides Shop window hardware

Extra Security

Patio door locks, sash jammers, letterbox security, door chains and key safes.

All 21 Extra Security guides
Extra Security guides Shop security

Draughts, Leaks & Ventilation

Stop rain under the door, replace seals and gaskets, fit weather bars and trickle vents.

All 6 Draughts, Leaks & Ventilation guides
Draughts, Leaks & Ventilation guides Shop seals & draught proofing

Fixings & Repairs

The right screws for uPVC, jack nuts for stripped holes, and lock care.

Fixings & Repairs guides Shop screws & fixings

Quick answers

Short answers from our guides. Tap a question to see the answer.

How do I measure a euro cylinder lock?

Measure from the centre of the fixing screw on the edge of the door to each end of the cylinder, and write it as internal × external, for example 40 × 50mm. Sizes go up in 5mm steps, and more than 4 in 10 of the cylinders we sell are a different length on each side, so always measure both.

Read the guide: How to Measure a Euro Cylinder Lock (UK Size Guide)

What size is an internal door latch?

UK internal door latches are 64mm (2½″) or 76mm (3″). Measure from the edge of the door to the centre of the handle: about 44mm means a 64mm latch, and about 57mm means a 76mm latch.

Read the guide: How to Measure an Internal Door Latch: 64mm vs 76mm (UK Size Guide)

What does TS007 3-star mean?

TS007 is the UK Kitemark standard for euro cylinders and door handles, tested against snapping, drilling and picking. You need 3 stars in total on the door: a 3-star cylinder gets you there on its own, while a 1-star cylinder needs a 2-star security handle as well.

Read the guide: TS007 3-Star Euro Cylinders: What the Rating Means and Which to Buy

Why is my key hard to turn?

Turn the key with the door open. If it's easy, the door has moved and needs adjusting; if it's still stiff, puff a little graphite powder into the keyhole and work the key back and forth. Don't use WD-40 or oil, which collects dust and makes the lock stiffer over time.

Read the guide: Key Hard to Turn in Your Door Lock? Causes and How to Fix It

How do I know if my uPVC door gearbox is failing?

Signs are a floppy or drooping handle, a handle that's getting harder to lift, a key that turns but doesn't lock, and clicking or grinding inside the door. Test with the door open first: if everything works smoothly then, the door is out of line, and that needs fixing before a new gearbox.

Read the guide: Signs Your uPVC Door Gearbox Is Failing (and the 30-Second Test)

Can you replace hinges on a uPVC door?

Yes, without replacing the door. Match the type (butt, rebated or flag hinge), the size and profile, and the colour, then support the door and change one hinge at a time. If the door has only dropped, try adjusting the hinges first.

Read the guide: Can You Replace Hinges on a uPVC Door? (Yes: Here's How)

How do I stop rain coming in under my front door?

First clear the drainage holes in the threshold, which costs nothing and is a common cause. Then check the seals, whether the door has dropped, and the sealant round the frame. If rain only gets in during heavy weather, fit a weather bar to the bottom of the door.

Read the guide: How to Stop Rainwater Leaking Under Your Front Door

Can I get one key for all my doors?

Yes. You can't cut one key to fit your existing locks, but you can swap the lock barrel in each door for a matching set that shares one key. It's called keyed alike, and each barrel takes about 10 minutes to fit with a screwdriver.

Read the guide: How to Get the Same Key for All Your Doors

Will a sash jammer work on my door or window?

Only if it opens inwards. A sash jammer screws to the inside of the frame and its arm swings over the door or window so it can't be pushed open. Use 2 on a door, 2 on the inside letterbox flap to make a letterbox lock, and 1 or 2 on an inward-opening window.

Read the guide: How to Fit a Sash Jammer to uPVC Doors, Windows and Letterboxes

How much does it cost to get a key cut?

It depends on the key type: standard door keys are the cheapest to copy, and 3 or more of the same key saves 20%. High-security keys cost more, and Avocet ABS and Yale Platinum keys can be cut from the code on your key card.

Read the guide: How Much Does It Cost to Get a Key Cut? Prices from £2.80 (2026)

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