The short answer
Often yes. A roof window on a low or easily reached slope can be fitted using a tower, or a roof ladder, and nothing more. A window well up a main slope, or over a pavement or road, is safer with scaffold. Under the Highways Act 1980, the highway authority must grant a licence before scaffold goes up on the road or pavement.
Low slopes: tower and roof ladder
A roof ladder has wheels and a hook that fits over the ridge, so it lies flat along the slope and spreads the load. It gives a fitter a firm place to kneel on a gentle or moderate pitch, and it suits small jobs near the eaves: a window in a porch roof, a single-storey extension or the cheek of a dormer.
A mobile tower is a platform on wheels. It works where the ground is firm and level, the window is within reach of the deck, and there is room beside the house to set it up. For a swap on a low slope, a tower plus a roof ladder is often all the access the job needs.
Both are tools for a job that stays small. Fitting a window means lifting tiles, handling a frame about the size of a door panel and moving materials up and down, and each extra metre of height makes every one of those tasks harder to do safely.
Our answer on replacing a roof window from inside covers the swaps that need very little outside access at all.
When the window calls for a full scaffold
Scaffold earns its place higher up the slope. Edge protection stops a person or a tool going over, a working platform gives room to move, and a proper structure lets us stack and cut tiles beside the window without leaning out over the edge.
The signs are simple. A window in the upper half of a two-storey slope, a steep pitch where a roof ladder feels thin, a long open edge or a position above a drive, path or pavement all point to scaffold. So does a new opening, because cutting into the roof structure uncovers a larger area than a swap does.
Nobody is helped by a firm that takes a risk to save on set-up. If a quote for a high slope has no access allowed, ask the firm how it plans to reach the roof.
At survey stage we check the position and tell you which method suits, with photos showing why. The same thinking applies to scaffolding for slate repairs, where fragile slates add a second reason to keep fitters off the roof surface.
The highway licence, in plain words
A licence concerns only the public highway, so scaffold that stays on private ground is a different matter. Section 169 of the Highways Act 1980 prohibits erecting or keeping on or over a highway any scaffolding that obstructs it, unless the highway authority has granted a licence.
That authority is not the district council. At every Hampshire district address, Test Valley and its neighbours included, it is Hampshire County Council, and Hampshire County Council expects the scaffold firm to be the applicant. Its own page also asks for a clear notice period before the start date, so a window job on a pavement-side house needs planning well ahead of the booking.
Wiltshire Council and West Berkshire Council each run their own process, and each states that the scaffold firm is the applicant. Other highway authorities set their own rules and charges.
A licence needs the right paperwork and a gap before the start date, which is why we sort it with the scaffolder in the survey stage. You are not left to chase an application, and the job does not stall on the day.
What this means for the price and the day
Access is among the biggest things that move a roof window price. A swap from a ladder on a low roof is one of the smaller jobs on a roof, while a high window with licensed scaffold is a bigger operation altogether. That is why a quote for one window can sit well above or below a guide figure.
When you compare quotes, ask what each firm has allowed for access. A total that leaves scaffolding out looks cheaper for a reason you will meet later, and it is worth asking whether VAT is in it too.
Weather plays a part. Wind makes working from a roof ladder or a platform unsafe, and a roof cannot be left open in the rain, so a good plan keeps the opening small and covers it each time work stops. Where the frame can go in during one visit, the roof is closed up again before nightfall.
For the typical UK range on the window itself, read how much it costs to fit a new roof window, and for the whole service see roof windows and skylights.
