Replacement uPVC Window Handles: What If Screw Centres Don’t Match?

Replacing a UPVC window handle is a common maintenance task for homeowners and tradespeople, but the job becomes trickier when screw centres don’t match. Choosing the correct replacement upvc window handles involves measuring accurately, understanding handle types and backplate sizes, and knowing when adaptors or slight modifications are acceptable. This article explains practical options and step-by-step solutions to get a secure, neat finish.

Understand screw centres and why they matter

Screw centres refer to the distance between the fixing holes on a handle’s backplate, usually measured in millimetres. The most common centres for UPVC window handles are 43mm, 45mm and occasionally 92mm depending on handle type and manufacturer. If the replacement handle’s screw centres don’t align with the existing holes, the handle won’t sit flush or may not secure properly, which can affect the lock function and overall window performance.

Matching screw centres preserves the aesthetics and avoids unnecessary drilling or filling. However, exact matches are not always possible when replacing older or non-standard handles. Practical solutions exist to adapt handles with different centres without compromising safety.

Identify handle type and backplate style

Before selecting a replacement, identify whether the window uses an espag handle, cockspur handle, or a different style, since each type has different fixing methods.

• Espag handles attach to a spindle and typically have two screw fixings along a backplate. Consider modern designs like the TSS Cockspur Window Handles which are designed to fit most upvc window profiles but still require attention to screw centres.
• Cockspur handles are surface-mounted and screw into the window frame with a visible backplate; the TSS Cockspur Window Handle is an example of a straightforward replacement for older cockspur fittings.
• Some handles like the TSS Offset UPVC Window Handles offer universal spindles or multi-fix backplates to increase compatibility.

Check whether the existing handle uses a round or flat spindle and whether the fixation screws are countersunk or raised, as these details affect fit.

Measure accurately: tools and technique

Accurate measurement prevents mistakes. Tools required: tape measure or calipers, pencil, and masking tape.

1. Measure the screw centres from the middle of one screw hole to the middle of the other, not from edge to edge. 2. Measure the spindle length and width. For espag handles the spindle is often 7mm or 8mm square; verify using calipers. 3. Note the overall backplate height and width to ensure the new handle will not overlap existing paint or glazing sealant. 4. Photograph the existing handle in situ to capture orientation and any hidden fixings.

Record measurements in millimetres and double-check them. Manufacturers sometimes list screw centres in product specifications; cross-reference measurements with available product data.

Practical solutions when centres don’t match

Several workable options exist if replacement upvc window handles have mismatched screw centres:

• Use a universal or adjustable backplate: Some replacement handles include elongated fixing slots instead of fixed holes, allowing a small range of adjustment. This avoids new drilling and can accommodate variations of a few millimetres.
• Use longer screws with a washer or nylon spacer: If the new handle’s holes are slightly off, longer screws with a thin washer can bridge the gap, but only if the handle still aligns functionally with the spindle.
• Use a mounting plate or adaptor: Small steel or plastic adaptor plates can be fixed to the window, providing new fixing points matching the replacement handle. This is useful where aesthetics are acceptable and the adaptor is concealed under the handle.
• Re-drill and fill old holes: When holes need moving more than a few millimetres, drill new holes in the frame and fill the old ones with a compatible filler such as epoxy resin or PU foam for a strong repair. Allow full cure before fitting the new handle.
• Replace the frame’s fixing block: Some UPVC frames have replaceable fixing blocks. If the existing block is cracked or non-standard, replacing it restores correct centres for compatible handles. This option is more involved and may require partial sash removal.

Choose the least invasive option that maintains mechanical integrity and appearance. Filling and re-drilling is common but requires patience to ensure the filler bonds well and does not trap moisture.

Installation tips and best practice

• Prepare the surface: Clean the frame and remove old sealant. Masking tape around the work area protects the frame finish.
• Use the correct screws: Stainless steel screws resist corrosion. Match screw length to the frame thickness to avoid protrusion or strip-out.
• Apply threadlocker sparingly: A small amount of blue threadlocker prevents screws loosening over time without making future removal difficult.
• Align the spindle properly: Ensure the spindle engages with the gearbox inside the window before tightening fixings. Misalignment can cause jamming or damage to the locking mechanism.
• Test operation before final tightening: Open and close the window several times to confirm the handle operates smoothly and the lock engages correctly.
• Seal around fixings: If holes have been drilled through to the external face, seal with a silicone or appropriate sealant to prevent water ingress.

For tradespeople, carrying a small assortment of backplates, spindles and fixings on-site reduces return visits and allows immediate adaptation for most mismatches.

When to replace the whole handle set or call a specialist

If the locking mechanism within the multi-point espagnolette is damaged, the window sash is warped, or repeated problems occur after several repair attempts, replacing the entire handle and gearbox set may be the best long-term solution. Complex sash removals, damaged reinforcement, or heritage windows with bespoke fittings warrant specialist attention.

Safety-critical issues such as broken locks on upstairs windows or compromised security should be resolved promptly by a qualified fitter to ensure compliance with building and insurance requirements.

Final checklist before ordering

• Confirm screw centres, spindle size and handle type.
• Decide whether a universal backplate or adaptor is acceptable.
• Choose corrosion-resistant fixings and appropriate sealant.
• Keep photographs and measurements for reference when ordering.

Replacement upvc window handles are straightforward when measurements and compatibility are checked in advance. With accurate measurement, the right replacement part and basic tools, mismatched screw centres can be resolved with minimal fuss.

Window Handles Guide