An installer fitting a new double glazed window
Process, regs & planning · Guide

How long does it take to fit double glazing?

Per window, for a whole house, plus survey and lead times — the typical timescales explained.

Updated June 2026Sourced from trade and government guidance
DG
Double Glazing Answers editorial
Reviewed against FENSA, CERTASS, the BFRC, Building Regulations Part L and Part F, the Glass and Glazing Federation (GGF) and the Energy Saving Trust. We are an independent information and introduction service, not a window installer.

The short answer

Once on site, a single window typically takes around 30 minutes to an hour to fit, and a whole house of 8–10 windows is usually done in one to three days. The fitting itself is quick; the longer wait is the lead time before fitting day — after the survey, made-to-measure windows usually take a few weeks to manufacture and schedule. Larger jobs, awkward access, bay windows or rendered reveals add time. See double glazing installation: what to expect for the day-by-day picture.

People usually ask this for two reasons: how disruptive will the fitting be, and how long from ordering to finished. This guide covers both — the time per window and per house on fitting day, and the typical lead time from survey to installation.

Timescales at a glance

Time on fitting day

The actual fitting is faster than most people expect. A standard window is generally out and replaced in around 30 minutes to an hour, including removing the old frame, fitting and sealing the new one, and tidying up. A typical three-bed house with 8–10 windows is usually completed within one to three days, often by a two-person team working through the property room by room. Doors, bay windows and larger or awkward openings take longer.

JobTypical time on site
Single standard window~30–60 minutes
Bay windowHalf a day or more
Whole house (8–10 windows)1–3 days
DoorsA few hours each

Survey and lead time

The bigger part of the timeline is usually the wait before fitting day. Reputable installers carry out a technical survey to measure each opening precisely, then the windows are manufactured to measure — this typically takes a few weeks. So from signing the order to the fitters arriving, a few weeks is normal, sometimes longer in busy periods or for non-standard styles and colours. The fitting itself, by contrast, is short.

What can add time: bay windows, rendered or rebuilt reveals, awkward access (scaffolding for upper floors), structural repairs found on removal, and non-standard sizes or colours with longer manufacturing lead times. A good installer flags these at the survey.

Keeping disruption manageable

Because installers work room by room and each window is quick, your home stays broadly liveable during a whole-house job — you are not without windows everywhere at once. Plan for some dust and noise, clear access to each window beforehand, and expect the team to make each opening weathertight the same day. These are typical timescales only; your actual timeline depends on the number and type of windows, access, and your installer’s schedule. This is general guidance, not a commitment for any specific job.

Compare double glazing quotes

Ask each installer for their lead time and fitting schedule so you can compare on timing as well as price. Use our service to reach FENSA or CERTASS registered installers in your area.

Free to use. No obligation. We are an independent guide, not an installer.

Frequently asked questions

How long does it take to fit one window?

A standard window is usually fitted in around 30 minutes to an hour, including removing the old frame, fitting and sealing the new one. Bay windows and larger or awkward openings take longer.

How long to fit double glazing in a whole house?

A typical three-bed house with 8–10 windows is usually completed within one to three days, often by a two-person team working room by room. Larger properties, doors and bay windows add time.

How long from ordering to installation?

After the survey, made-to-measure windows typically take a few weeks to manufacture and schedule, so a few weeks from order to fitting day is normal — sometimes longer in busy periods or for non-standard styles and colours.

Will I be without windows during the work?

No — installers work one opening at a time and make each window weathertight the same day, so your home stays broadly liveable. You are not left without windows across the whole property at once.

Sources & further reading

This is general information, not a commitment for any specific job. Actual timescales depend on the number and type of windows, access and your installer’s schedule. Replacement windows should be fitted by a FENSA or CERTASS registered window installer. We are an independent information and introduction service, not an installer.