A straightforward single window into a modern trussed roof is a day, including the reveal being left ready for plastering. A like for like replacement into an existing opening is often less. What extends it is the covering, the access and the number of openings, in that order, and none of those has anything to do with the window itself.
How long a rooflight job takes generally
What sets the duration on any rooflight job is on how long does a flat roof rooflight take to install.
This page covers only what is different about a boxed branded roof window on a pitched slope.
Why the components save time
Because the thinking has already been done.
Brackets, an insulation collar, a vapour collar and a flashing kit all arrive made for the size code, so the detail is assembled rather than devised on the roof.
That is worth an hour or two against a bespoke unit on the same roof.
The brackets are already positioned
A small thing that matters on the day.
Fixing brackets locate against marks on the frame, so the frame is set square and at the right height in the opening without measuring from first principles.
It removes the step where things usually go slightly wrong.
The sash comes out
Which changes what is being lifted.
An empty frame is passed up and set, and the glazed sash goes in afterwards, so the heavy awkward part is handled last and at a moment when the frame is already secure.
The kit arrives as a set
Rather than as sheet material to be formed.
Side, head and sill flashings are pressed for the size and the covering, so dressing them is fitting rather than fabricating.
What that kit contains is on what is a flashing kit.
What a like for like swap saves
The whole of the structural and most of the covering work.
The opening exists, the trimmers are there and the courses above and below are already cut to the right line, so the job is a lift, a swap and a reinstatement.
Half a day is realistic where nothing has rotted.
What extends it on a Sussex covering
Setting out, not cutting.
A hand made clay peg tile roof has an irregular gauge, so the courses either side of the opening have to be set out to look right rather than simply put back.
That is the guide on flashing an irregular gauge.
What extends it on a slate roof
Care and breakage.
Slates are cut and hooked or nailed individually, and an old covering breaks under handling, so time goes into working slowly and into finding replacements.
What the access adds
Sometimes a day before anybody starts.
A scaffold has to go up and come down, and where a tower will not reach or cannot stand, that is a separate visit at each end.
Where the ground is difficult, as on a town centre terrace, it is the largest variable.
Several windows in one visit
Much less than the sum of the parts.
Access, protection and setting out happen once, so a second window on the same slope is an opening and a set of courses rather than another day.
The reveal afterwards
A separate trade, and it is why the room is not finished on the day.
Insulating and boarding the reveal is part of the installation. Skimming, drying and decorating is plastering work that follows.
It is usually the plaster drying that decides when a room is usable.
An electric or solar unit
Adds a little, and less than people expect.
A solar unit needs no cable and is barely longer than a manual one. A mains unit needs an electrician, which is a separate visit rather than a longer day.
That is on the electric rooflight installation page.
A recessed installation
Longer, and deliberately so.
Setting the frame deeper into the covering means more work at the opening and a more involved flashing detail, which is time bought for appearance.
It is described on what is a VELUX recessed installation.
Weather
The reason a date sometimes moves.
The roof is open for part of the day, and a job is postponed rather than started on a forecast that will not hold, which is the right decision even when it is the inconvenient one.
What happens before the day
Ordering, and it is not instant.
The window, the kit and the collars are ordered against the code once the survey has confirmed it, and a common size is quick where an unusual one carries a lead time.
The install date follows the delivery rather than the enquiry.
What is asked of the household
Very little, and it saves an hour.
Clearing the loft around the position, moving furniture from under the opening and leaving access to the room is the whole of it, and a loft that has not been cleared is the commonest late start.
Where an inspection sits in the programme
Between the structure and the covering, where one is needed.
Notifiable work is inspected at a stage where the trimming is visible, which means the job is sequenced around a visit rather than closed up and opened again.
On a single window that is usually a phone call rather than a delay.
What we give you on a VELUX
We give a duration after seeing the covering and the access rather than from the size code, because those are what actually decide it, and we sequence so the roof is closed before we leave.
The rest is on the VELUX window installation page.
Thinking about this job? We survey across Worthing, West Sussex and the South Downs and give you a fixed price before any work starts, with a 10-year workmanship guarantee.