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How long does window installation take?

It is the first thing most people ask: how long will my house be a building site? The honest answer is less time than you would think. Fitting is quick — the longer wait is for your made-to-measure windows to be manufactured. Here are realistic window installation times to plan around.

Fitting time per window

As a rule of thumb, a single, straightforward replacement window takes a two-person crew around 60 to 90 minutes from removing the old unit to sealing the new one. That figure covers most standard casement windows. Larger or more complex openings take longer:

• Standard casement: roughly 1 to 1.5 hours.
• Bay window: half a day, because the frame is built up in sections and needs careful levelling.
• Sash windows: a little longer than casements, especially in period openings that are out of square.
• Doors (patio or French): two to four hours depending on size and threshold work.

How long for a whole house?

Most terraced and semi-detached homes with eight to twelve windows are completed in one to two days. A larger detached property, or a job that includes doors and a bay, may run to three days. A single crew will usually work through the house room by room so you are never left exposed — exactly as described in our installation day guide.

The bigger wait: manufacturing

The fitting itself is fast; the lead time is mostly your windows being made to measure. From the survey, expect two to four weeks for standard units, and longer for bespoke shapes, sculpted or heritage frames, or special colours. This is why the process from enquiry to fit typically spans three to six weeks overall, as set out in our step-by-step buying process. Installers have survey appointments in many areas this month, so the clock usually starts quickly.

What can slow things down

A few things add time, and a good surveyor will flag them upfront:

• Access: upstairs windows needing scaffolding or a tower take longer to set up.
• Structural surprises: a rotten lintel or crumbling sill found on the day needs making good first.
• Weather: heavy rain or high winds can pause work at height for safety.
• Bay and feature windows: more sections mean more careful, slower fitting.

Choosing a crew you have taken care vetting your installer first means realistic timings and fewer surprises. Getting the job done well the first time also means the new units start solving the everyday problems new windows solve straight away, and your certificate follows shortly after. If windows are part of a wider project, a home improvement quote comparison helps you sequence the work.

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