How to Lock a VELUX Roof Window and Check That It’s Secure

A roof window that appears closed is not necessarily latched. On many VELUX models, the handle or control bar must return to a particular position for the sash to be secure. Because different generations work differently, identify your window before forcing a stiff handle.

Find the product identification

Check the manufacturer’s identification plate, commonly visible when the window is opened, and note the model and production details. Then consult the instructions for that specific unit. A top-hung, center-pivot, electric or solar-operated window can have different closing controls.

Check the closing position

Close the sash slowly and make sure no fabric, insect screen or debris obstructs the sealing surface. Return the control bar or handle to its prescribed closed position. Gently check that the sash does not pull open without operating the control. Never lean out of an upper-story window to test it.

When it won’t latch

Inspect accessible seals and hardware for visible dirt, damaged fittings or an obstruction. Do not repeatedly force the handle. If the sash is twisted or the frame has shifted, a manufacturer-approved service adjustment may be required. For powered models, follow the manual’s reset and troubleshooting steps; do not dismantle wiring or motors yourself.

Ventilation is not full locking

Some roof windows offer a ventilation flap or limited opening position. This may be appropriate for air circulation, but it should not be treated as equivalent to a fully closed and locked window, particularly when the home is empty.

Security and escape

Consider whether the window provides emergency access or an escape route before installing any additional latch. Adding incompatible hardware can compromise the window’s function, water resistance or warranty. A secure home also depends on appropriately protected lower-level openings; see our window security guide and basement window precautions.

Maintenance that matters

Keep drainage channels clear where safely accessible and inspect seals regularly. Record the model before ordering replacement parts. If you encounter leaks, cracked glazing or a sash that no longer fits evenly, arrange a qualified inspection rather than attempting to compensate with extra force.