Can a skylight be replaced without scaffolding?

On a pitched roof, the usual candidate is a roof window sitting in the plane of the slope. When the old unit and the new one are the same size and the covering around the frame is sound, the swap can be planned so that the removal and the fitting are done from inside the room.

Inside access has limits, because the flashing and the roof covering sit on the outside of the frame. That is the reason the survey looks at the roof from outside before anything is promised, and a photo sent in advance is only a start. Where the unit is high in the ceiling or on a steep slope, the answer can change.

A flat rooflight or lantern is fitted from the roof itself, so someone has to get up there and work safely near the edge. A scaffold tower is one way, and edge protection fixed to the building is another. Which suits depends on the height of the roof, whether there is clear ground beside the wall, and how far the unit has to be carried. The firmness and levelness of the ground at the foot of the wall decide where a tower can stand. A single-storey extension with a clear side garden presents a different problem from a flat roof over a first-floor rear addition.

Full scaffolding goes up when a tower or edge protection would not give safe, stable working at the roof. That can be a tall house, where the eaves sit high above the ground. It can be a larger rooflight or a roof lantern, which is heavy enough to need lifting and setting by more than one person.

Scaffolding is a hire and erection cost on top of the unit, so it can make a large difference between two quotes for the same rooflight.

The survey measures the unit and the opening, looks at the slope and covering, and checks how the roof can be reached. Ground conditions beside the wall, the width of side access and the height of the eaves all feed into it.

Access is a real cost, so the same unit in two houses can be priced differently. Changing from inside costs less in equipment than a tower, and a tower costs less than full scaffolding. The route chosen at the free survey sets the fixed written quote, never a guess from a photo. For the wider list of price factors, see the cost to replace a skylight.

The access question is a good moment to think about use. A roof window that sits high can be fitted with a control rod or an electric opener, so nobody needs a stool. A blind can be chosen for the room, such as blackout for a bedroom or a damp-room blind for a bathroom, and the blind is ordered against the size code of that unit and the name of the maker. A child-safe restrictor is an option on some models, and a remote handset can live on a high shelf. The choice starts from who opens the unit and how high it sits.

Access matters again once the new unit is in. A centre-pivot roof window swings round, so the outside of the glass comes in to face the room and is wiped indoors. A flat rooflight or lantern has to be cleaned from outside. Reaching it from the ground is possible with a water-fed pole; failing that, a ladder reaches the roof edge. Walk-on units are the only ones built for standing on. Before we leave, the controls and the cleaning are run through with you. For planning this ahead, moving the position would make it a new opening rather than a swap, with a different route to the roof.