A recessed installation uses a different flashing kit to set the frame lower into the roof build up, so the glass sits much closer to the plane of the tiles or slates. From the ground the window reads as part of the roof rather than as something sitting on it, and on a visible slope that is a substantial difference for a modest amount of extra work.
What a standard installation looks like
The frame sits with its top surface above the covering line.
A standard kit weathers the window where it sits, which is proud of the tiles by the depth of the frame and the flashing, and from the garden the unit reads as a raised rectangle with a visible surround.
On most roofs nobody minds.
What a recessed installation changes
The depth, and therefore the shadow.
Setting the frame lower means less of it stands proud, so the eye reads a pane in the roof rather than a box on it, and the metal surround largely disappears.
It is a shadow line rather than a silhouette.
How it is achieved
With a kit made for the purpose.
The recessed kit carries deeper side sections and a different head and sill arrangement, so the covering can come up closer to the glass while the water still gets out.
It is not a standard kit fitted lower.
What changes in the opening
The frame sits deeper relative to the rafters.
The brackets are positioned lower and the underlay collar is formed to suit, so the whole detail is set out differently from the start rather than adjusted at the end.
Where it earns its keep
A front slope, a conservation area, a village street.
Anywhere the roof is seen and the appearance of a standard unit would be the objection, a recessed installation is the specification that answers it.
Where that matters is on do I need permission for a rooflight in a conservation area.
Whether it satisfies a conservation officer
Sometimes, and it is a conversation rather than a rule.
Some authorities accept a recessed standard unit on a less prominent slope and ask for a conservation rooflight where the roof is prominent.
It varies across our area and it is worth asking before ordering.
How it differs from a conservation rooflight
A different product entirely.
A conservation rooflight is a steel framed unit with a central glazing bar and its own proportions, made to look like a Victorian original.
A recessed standard window is a modern window sitting low. Both sit flat and they do not look alike.
The comparison is on how flush does a conservation rooflight sit.
What it adds to the work
Time at the opening and time at the covering.
The frame position has to be set precisely, the covering is cut closer to the frame, and the flashing detail has more parts to dress.
It is a few hours rather than a different job.
What it adds to the cost
A step on the kit and a step on the labour.
Neither is dramatic against the whole job, and where the appearance is the reason for the work it is money spent on the thing being bought.
Where it falls in a quotation is on how much does a VELUX window cost.
Which coverings suit it
Flat and shallow profiles best.
Slate, plain tile and flat concrete tile recess cleanly. A deep pantile has a contour that a recessed detail has to work harder against.
The covering is checked before it is offered.
The build up depth
The practical constraint on some roofs.
Setting a frame lower needs depth in the roof to set it into, and a shallow rafter with a thick insulation layer can leave less room than the detail wants.
It is measured in the loft rather than assumed.
What it does to the reveal inside
Very little, and slightly more depth.
The frame sitting lower means the internal reveal is marginally deeper, which is generally unnoticeable and occasionally an improvement.
Whether it affects planning
Helpfully, on the projection test.
Permitted development limits how far a rooflight may project beyond the roof plane, and a recessed installation reduces that projection considerably.
The tests are on do roof windows need planning permission.
Whether it affects performance
No, and it is worth saying.
The window is the same window with the same glazing and the same figures. What changes is where it sits in the roof.
Whether it leaks any more
Not when the kit is used as intended.
The recessed kit is engineered for the position, and the failures come from setting a standard unit low without the right components rather than from the principle.
Retro fitting it to an existing window
Possible, and it is a real job.
Changing a standard installation to a recessed one means resetting the frame in the opening and renewing the kit, which is most of a replacement.
It is usually done when the window is being changed anyway.
Combining it with two windows
Available, and it looks very good.
Recessed combination kits exist for a pair, and two units sitting low with a formed gutter between them read as a single considered opening.
How it reads at night
A detail worth mentioning because it is the one people notice from the street.
A lit window low in a roof reads as a panel of light in the covering, where a proud unit reads as a lantern standing off it, and on a village street after dark that difference is more obvious than in daylight.
What to ask an installer
Two questions, and they settle whether it has been done properly.
Which recessed kit is being used, and how the covering will be cut and set out around it, because a recessed detail lives or dies on how close the tiles come and how true the courses run.
What we offer
We offer it wherever the roof is seen from a street or a garden, because the difference in appearance is out of proportion to the difference in cost, and homeowners are rarely told the option exists.
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.