How long does a replacement glass unit take to arrive?

Each sealed unit is cut, assembled and sealed to fit one opening, so it only exists once someone has measured and ordered it.

Rooflight openings are not standard. Two kitchen extensions built the same year can have frames that differ by a few millimetres, and an old lantern may have panels cut to angles that no catalogue lists. A sealed unit has to fit its rebate closely, with the right clearance all round, or it will not sit on its gaskets properly. So the unit is made from the measurements taken at your house, in a factory that builds sealed units to order.

That is also why the survey comes first. Nothing can be ordered until the existing unit has been measured and the new build has been chosen. A rough estimate from a photograph will not do, because a unit that is a few millimetres wrong arrives unusable. How that measuring is done is set out in how a failed rooflight is measured for its replacement.

The sequence, without any promises on timing, runs like this:

1. You send photographs or ask for a survey through the quote form.
2. We visit, measure the frame and unit, note the glazing and listen to the room.
3. You receive a written quote with the proposed glass build and, where it applies, the quiet spec.
4. You accept, and the unit is ordered from the maker.
5. The maker confirms a production and delivery date, and we pass it on to you in writing.
6. We book the fitting for a day after the unit has arrived and has been checked against the opening.

Four things move the date more than anything else, and the survey tells us which of them apply to you.

Glass build is the one you control. A plain toughened unit is the simplest thing to make. A laminated acoustic inner pane is bonded from two sheets with an interlayer, then built into the sealed unit, and that extra stage can take longer. The same is true of a thicker outer pane, because thick glass is handled and toughened in its own batches. It is sensible to accept that a quieter build may mean a longer wait, and to weigh it against the room. A bedroom under a busy flight path may justify it. A utility room may not.

Size matters because large units need careful handling. A lantern panel cut to a pitched angle takes more care than a plain rectangle. And if the rooflight is an older or unusual product, the question can move from timing to whether the maker still supplies it, which is covered in replacement units for a skylight that is no longer made.

A date quoted before the maker has accepted the order is a guess, and we would sooner give you a fact.

The length of time a maker needs changes with their workload, with the season, and with the glass you have chosen. Quoting a number of weeks on the website would be stating something we cannot stand behind for your particular unit. So the date is confirmed in writing after the order is placed. It comes from the maker's own acknowledgement, and it is the date we plan the fitting around.

What we can say at the survey is which of the factors above apply, and whether any of them is likely to lengthen the wait. If you are choosing between two glass builds, we can tell you which one involves the extra stage. That lets you decide with the trade-off in front of you. The choice is written into your quiet spec, so the build and the reasoning are on one page.

The time between survey and fitting is useful: it is when the decisions get made calmly.

A failed unit does not become more dangerous while you wait, and it will not correct itself either. You can live with mist for a while. The page on whether a misted rooflight is dangerous says what to watch for. A cracked pane is different, and needs a quicker decision, so tell us at the survey if you can see one.

Use the wait to settle what else you want from the new unit:

• whether a quieter inner pane is worth it for this room;
• whether to renew neighbouring units at the same visit, which saves access costs;
• whether the frame should be replaced at the same time;
• what to clear around the rooflight on the day, inside and out.

The comparison between renewing the unit or the whole rooflight is in replacing the glass unit or the whole rooflight. Our page on upgrading the glazing when a unit fails covers the glass options, and the price side is on the costs page.

We cover Crawley and 30 miles around. Work is installed to current Building Regulations, we handle the Building Control notification where the work is notifiable, and it carries a 10-year workmanship guarantee.

Can I pay for the unit to be made faster?

It depends on the maker's process, not on us. Where an option exists, it is written in the quote as a choice with its consequences, never added silently.

Will you fit the unit on the day it arrives?

We check the delivered unit against the opening first, then fit on the booked day. A wrongly sized unit that is fitted in a hurry is worse than a short delay.

Does a lantern with many panels take longer?

It can, because each panel is its own unit. The survey works out whether they are ordered together or in stages. See misted roof lantern panels for how lantern units are handled.

What if my old unit has no maker's mark?

The measurements and the glass build are what count, not the label. We record both at the survey and order to match or to upgrade.

Ready to start the clock? Send photographs on WhatsApp, or read the parent guide to misted and failed rooflight replacement in Crawley.