The Window Installation Sequence, Step by Step

1. Survey and coordination

The survey records more than width and height. It identifies opening condition, substrate, access, floor level, external finish, sill geometry and nearby services. Measurements should be tied to agreed reference points and checked for square, level and plumb.

Responsibilities at each interface should be documented: who prepares the opening, who protects finishes, and how hidden conditions will be handled if discovered.

2. Preparation and setting out

The opening must be stable, clean and suitable for the specified fixing and sealant approach. Setting blocks and packers should support loads at intended locations without obstructing drainage. The frame is positioned with the required tolerances and perimeter space.

Foam alone should not be assumed to provide structural fixing or a complete weather seal. Products have defined roles, substrates and installation requirements.

3. Fixing, glazing and perimeter work

Fixings transfer loads to the surrounding construction. Their type, spacing, edge distance and corrosion resistance are project-specific. Frames need to remain aligned while avoiding distortion that could impair operation.

Perimeter sealing often includes distinct interior and exterior functions. Joint dimensions, backing material, surface preparation and sealant compatibility affect performance. Drainage exits must remain open.

4. Inspection and handover

• Operate every sash and lock.
• Inspect gaskets, beads and seals continuously.
• Confirm weep paths are clear.
• Remove labels according to guidance.
• Record product, glass and finish references.
• Provide cleaning and maintenance information.

Water testing or other verification should follow an agreed method where the project calls for it. Photographs of concealed stages can become useful property records.