How Much of a VELUX Replacement Is Done From Inside the Room?

A VELUX replacement runs as two connected pieces of work rather than one. On the roof, the fitter is dealing with tiles or slates, the flashing kit, the frame fixings and the weatherproofing that keeps water out. Inside the room, someone else, sometimes the same fitter between roof visits, is dealing with the lining, the plaster edge and whatever sits against the frame on the room side. The roof-side work decides whether the window keeps out weather. The room-side work decides what the finished opening looks like from the bed, the landing or the desk underneath it.

Peterborough's stock makes the split easy to picture. In a Bretton or Orton loft conversion the room side is usually a plastered stud lining a few decades old; in a Fletton-brick terrace it might be painted timber boarding fitted when the loft was first done out. Either way, that internal finish is the part the household actually sees every day, and it is a smaller share of the total job than the roof work that surrounds it.

The room is prepared first, and none of this involves opening the roof. Furniture and flooring near the window are covered, the blind is taken down (our guide to VELUX blinds covers the types and how each one comes off), and where the window is an INTEGRA model the mains or solar wiring is isolated before anything is disturbed. A quick check of the wiring for that kind of window is worth reading on its own, since whether an INTEGRA needs an electrician depends on how the original supply was run.

Once the room is protected, the internal lining or trim around the frame is lifted away so the fitter can reach the fixing points from inside as well as outside. On an older installation this can mean easing off timber architrave or cutting back a plastered reveal a short way; on a newer one it is often no more than unclipping a factory lining kit. Either way, this is the point where dust and mess are at their worst, and it is also the shortest stage of the whole job.

The sash, the outer frame and the old flashing come out through the roof, not through the room. That is deliberate: lifting a sash out through a loft hatch and down a staircase risks the walls, the stairs and the sash itself far more than lowering it from a ladder outside. The same logic applies in reverse when the new window goes in. So while the room is opened up to expose the frame, almost nothing of the old window itself passes back through it.

When the new window goes into the same opening as the old one, which is the usual case covered on replacing an old VELUX in the same opening, the room-side work is lighter still. The lining only needs to come away from the frame edge, not from the wider reveal, and there is no plastering out to a new, larger opening. A change of size, by contrast, means cutting back plaster or boarding well beyond the old frame, which is a longer job on the room side and worth flagging separately when a size change is being considered rather than assumed.

Whether the old flashing can stay in place or has to be renewed alongside the frame is a roof-side question rather than a room-side one, and it depends on the roof covering and the flashing's condition; that is set out on will a new VELUX fit my old VELUX flashing?.

Once the new frame is fixed and flashed from the roof side, the remaining work moves back inside. An insulation collar and a vapour barrier are fitted around the frame from the room, closing the gap between the frame and the surrounding structure so warm, moist room air cannot reach the cold roof timbers behind the lining. Our guide to VELUX installation collars and linings goes into what each layer does and why the order they go in matters.

The lining kit or plastered reveal goes back on last, and this is the stage that decides how much of the frame you actually see from the room once the job is finished. A deep reveal with a steep lining angle can hide more sky than a shallow one lined close to the frame, which is exactly the question answered on how much of the frame will I see from inside a VELUX?. It is also why we sketch the sightline from your side of the room before any of this starts, so the reveal is planned rather than an afterthought.

The last stage is finishing, and it happens entirely inside. Plaster edges are made good and left to dry, boarded linings are filled and sanded, and any trim or architrave is refitted or replaced to match what was there. Painting the reveal is usually left to the homeowner once plaster has had time to dry out properly, since painting over damp plaster traps moisture rather than sealing it in. The blind goes back on last, once the frame and lining are dry and settled, so it is not sitting against wet plaster while it cures.

None of this making-good stage touches the roof again. By the time the room is being finished, the flashing has already been tested against the weather from outside, and the household's part of the job, protecting the room, losing the old lining, then living with an open reveal for a short stretch, is effectively over.

The full sequence, roof-side and room-side together, is set out on our VELUX Window Installation in Peterborough page, alongside how the survey decides what stays and what is renewed for a specific roof and room. Understanding the room-side portion in advance is mostly about knowing what to move, what to cover, and how long the reveal will sit open before it is lined and made good again.

Do I need to clear the whole room, or just around the window?

Just around the window. Furniture and flooring directly beneath and either side of the frame need covering or moving; the rest of the room can carry on being used.

How long does the room stay opened up around the frame?

The lining is off for as long as the roof-side work takes, since the collar and vapour barrier cannot go in until the frame is fixed and flashed, then it is closed up and made good the same visit in most cases.

Will the blind fit straight back on once the window is replaced?

An existing blind can often be refitted if the new window is the same size and range, but a different size or model usually needs a new blind sized to match.

Does the room need repainting straight away?

No. Plaster needs time to dry out before it takes paint well, so painting the reveal is normally left until the new plaster has fully dried rather than done on the day of the fit.