Replacement Double Glazed Window Handles: DIY Fitting Steps

Replacement double glazed window handles can wear, break or simply go out of fashion. Replacing them is a straightforward task for a competent DIYer or tradesperson with basic tools and a clear method. This guide explains practical, step-by-step fitting of new window handles for common types found on UK double glazed windows, highlighting preparation, removal, measurement and installation to ensure a secure, long-lasting result.

Tools, materials and safety

Essential tools and materials:

• Screwdrivers (Pozidriv and flat)
• Torx bits if required by the handle
• Tape measure and vernier calipers (for accurate backset)
• Masking tape and pencil
• Replacement handle(s)
• Threadlocker (medium strength) or Loctite 243
• Cleaning cloth and mild detergent
• Protective goggles and gloves

Safety notes:

• Wear eye protection when working with metal and around glass.
• Support opening sashes to prevent sudden movement — place a wedge or prop under the sash.
• If the window is heavy or pinned, use two people to reduce risk of dropping the sash.

Identifying the handle type and measuring

Accurate identification matters for ordering a compatible replacement. Common types on double glazed windows include:

• Espag (espagnolette) handles — operate a multi-point locking mechanism via a spindle and espagnolette gearbox.
• Cockspur handles — a simple lever with a hook or spur that engages the frame.
• Tilt/turn and other proprietary handles — require measuring the rose size and spindle.

Make these key measurements:

• Backset: distance from handle spindle centre to the edge of the handle rose (commonly 22mm or 28mm).
• Fixing hole centres: for handles with two screws, measure the distance between screw centres.
• Spindle size: square spindle thickness (commonly 8mm) and length.
• Handle orientation: left- or right-handed fitting (which way the handle points when closed).

Record measurements precisely before ordering. For espag fittings, measure the gearbox height and the distance to the end of the espagnolette if possible.

Choosing a replacement

Select a handle that matches the measured backset, spindle size and fixing centres. For a secure, modern espag handle, consider the TSS Cockspur Window Handles. For traditional side-hung windows, a robust TSS Cockspur Window Handle is an appropriate option. For a widely used manufacturer's style, the TSS Offset UPVC Window Handles offers good compatibility with many standard gearboxes.

When matching finishes, choose corrosion-resistant materials for coastal locations and consider uPVC-specific fittings that include corrosion protection and stainless fixings.

Removing the old handle

1. Open the window to access the fixing screws on the inside face. Use a prop to support the sash if necessary. 2. Remove any decorative cover plates by levering gently with a flat screwdriver. 3. Unscrew the fixing screws while holding the handle to prevent it dropping. 4. Withdraw the spindle from the gear. For espag handles, the spindle may be firmly seated; pull evenly to avoid bending. 5. Inspect the gearbox or latch — look for wear, damaged splines or seized components. Replace the gearbox if wear is evident.

Mark the existing holes lightly with masking tape to preserve alignment and prevent damaging the frame while working.

Fitting the replacement handle — step by step

1. Clean the area where the new handle will sit. Remove old sealant, dirt and grease to ensure a flush fit. 2. Check the new handle's spindle and backset against the old measurements. If the spindle is too long, trim it carefully with a hacksaw, then file the cut square and remove burrs. 3. Insert the spindle fully into the gearbox or lock mechanism. For espag handles ensure the spindle engages with the internal actuator and the handle sits flush to the frame. 4. Align the handle rose so it matches the existing screw holes. Use a pilot screw to hold it in place, then fit the second screw. 5. Tighten screws evenly; avoid over-tightening into uPVC as this can crack the frame. Apply a small amount of medium-strength threadlocker to the fixing screws where appropriate. 6. Replace any decorative caps. Operate the handle through full travel several times to confirm smooth action and full engagement of the lock. 7. For espag handles fitted to multi-point locks, test the handle with the key or locking cylinder to ensure the shootbolts engage correctly.

If the handle has a locking feature, confirm the key rotates smoothly and the lock deadlocks in position. Lubricate moving parts with a dry PTFE spray rather than oil, which can attract dust.

Common problems and troubleshooting

• Handle wobbles after fitting: Check that the spindle is fully engaged and screws are tight. Use longer screws for soft frames if necessary, but avoid penetrating through the frame.
• Stiff operation: Verify spindle alignment and that the gearbox is not seized. Clean or replace a worn gearbox.
• Short handle throw (does not lock fully): Confirm correct backset and that the handle engages with the multi-point mechanism. Adjust the striker plates on the frame if needed.
• Wrong fixing centres: Use a universal adaptor plate or filler shims to accommodate different hole patterns, or consider replacing the lockcase to suit the chosen handle.

Maintenance tips for longevity

• Periodic lubrication of the gearbox and locking points with dry PTFE keeps action smooth without attracting grime.
• Tighten handle fixings every 12–18 months to prevent loosening from repeated use.
• Inspect for corrosion and replace handles in coastal properties with marine-grade stainless or corrosion-resistant finishes.
• Store spare fixings and a matching handle in a small home maintenance kit for quick repairs.

When to call a professional

Most replacement double glazed window handles can be fitted by a homeowner or tradesperson, but contact a professional fitter for:

• Complex multi-point lock replacements or if the sash needs removal.
• Significant damage to the frame or if the lockcase requires replacement.
• Windows under warranty where incorrect fitting could void coverage.

Replacement handles improve security, functionality and appearance. With correct measurement, the right tools and a stepwise approach, fitting new double glazed window handles is a manageable, cost-effective upgrade.

Window Handles Guide