The Final Look: A Daylight Inspection Routine for Newly Fitted Windows

Final payment is not a formality. It is the point at which the installation moves from the installer's responsibility to yours, and it deserves a measured look before the balance is released. The aim is not to hunt for fault in every pane, but to confirm that the windows supplied and fitted match the specification, operate correctly and are free from defects that a reasonable homeowner would notice.

At Crystal Clear Glazing Co., we recommend a simple principle: inspect calmly, record precisely and resolve fairly. A daylight inspection, carried out before cleaning and before the final payment, gives both parties a clear reference point.

Start with the paperwork, not the glass

Before you walk from room to room, check the contract and specification. Confirm the window sizes, frame colour, glazing type, handle style, ventilation provisions and any agreed extras. If the sealed units were specified with particular performance attributes, such as solar control or acoustic glazing, make sure the labels or documentation support that. Ask for the sealed unit specification if it has not already been supplied.

A clipboard or phone note is useful. Record the date, the rooms inspected and the names of anyone present. This is not an adversarial step; it is simply good administration. The clearer your notes, the easier it is for an installer to respond without ambiguity.

Inspect in daylight, from more than one angle

Artificial light can flatter glass, and direct sunlight can exaggerate minor reflections. Diffused daylight is the most useful condition. Stand inside each room and view the window straight on, then move to one side and look across the pane at an angle. Repeat from the other side where access allows. If it is safe and practical, inspect from outside as well, particularly where ground-floor windows are concerned.

Open and close every opening light. Check handles, hinges, locking points and any restrictors. Look at the frame joints, gaskets, drainage slots and reveals. A low-angle torch can be a useful secondary tool for highlighting scratches or seal irregularities, but it should not be the deciding test. Under a torch, almost every pane will show something; the question is whether the issue is visible in ordinary daylight and whether it affects performance or appearance.

Know what is normal in a sealed unit

Glass is not optically perfect. Standard float glass can carry a very slight tint, and low-emissivity coatings can produce a faint haze or colour shift depending on the light. Toughened glass may show a subtle roller-wave effect, and sealed units can have minor variations at the edge seal. These characteristics are generally within manufacturing tolerances and are not, by themselves, evidence of a faulty unit.

The distinction matters. A slight reflection pattern that moves as you change position is different from a persistent scratch. A faint colour difference between panes may be normal tint variation; a clearly mismatched pane in the same elevation is worth questioning. Most importantly, condensation inside the sealed unit is not normal. Mist between the panes indicates that the seal has failed and should be recorded as a defect.

The snagging list: what is worth recording

A practical snagging list should focus on issues that are visible, measurable or likely to affect performance. Look for scratches that catch a fingernail, chips at the glass edge, damaged or misaligned gaskets, gaps in the sealant line, and drainage slots that are blocked or painted over. Check that opening lights close flush and that locks engage without force.

Visible distortion is worth noting where it makes straight lines look wavy or affects the view in a way that is noticeable in normal use. Small reflections at the edge of a unit are common; a persistent optical defect across the central viewing area deserves a conversation. Also record any missing trickle vents, damaged handles, poorly fitted trims or internal condensation.

Record issues so they can be resolved

Photographs are helpful, but they need context. Take a wider shot showing the room and window, then a close-up with a ruler, coin or marked tape for scale. Note the room, the elevation, the pane and whether the issue is inside or outside. A small piece of removable tape on the glass can identify the exact spot, but avoid covering drainage slots or seal edges.

Put your observations in writing and send them promptly by email. Ask for a written response with a proposed remedy and timescale. If the contract includes a snagging period, check what it says. It is reasonable to ask the installer to inspect the issues with you before the balance is paid, but it is not usually reasonable to withhold the entire balance for a minor cosmetic point. Follow the contract terms, and seek independent advice if the disagreement is substantial.

Before you release the balance

Once the snagging points are agreed, confirm the completion paperwork. Ask for the relevant guarantee documents, any competent-person scheme certificate and confirmation that the installation has been notified under current Building Regulations where required. Check that the windows have been left clean, that fixings and trims are complete, and that you know how to operate and maintain the ventilation and hardware.

A final payment should mark a completed job, not the start of an unresolved argument. A careful daylight inspection, a clear written record and a fair response from both sides are the best way to ensure that the windows you have paid for are the windows you are content to live with.