Rooflights or skylights beneath Astley's colliery winding gear

The headframe at Astley Green, kept as part of a mining museum, tells you what built the village. Coal brought the terraces: short rows of red-brick houses for the miners, with slate roofs, small back yards and, behind them, an outrigger carrying the scullery. Many of those rows are still lived in, and their roofs are modest in size, with a single slope on each side of a ridge that a person can reach by ladder without much fuss.

Around the terraces, the older farm buildings remind you that Astley was farmland before and after the pit. Farmhouses and barns on the edge of the moss have been converted into family homes, and they bring a different roof altogether: tall, wide, timber-framed or steel-trussed slopes in slate or clay tile, with deep insulated build-ups added during the conversion.

Interwar and post-war semis line the main roads, and later estates from the 1970s onwards fill the space behind them. Between the two sit the plain brick semis with bay windows and hipped roofs, whose lofts are generous and whose landings often have no window at all. Some of the later housing is quite recent, built as infill on land beside the village. The newer houses mostly have simple gabled roofs in concrete interlocking tile, and many have had a loft converted since they were built.

The two ends of this range need quite different thinking. A terrace roof is built from sawn common rafters that rest on a purlin, so a roof window can be fitted by trimming an opening, a method that has worked for a century. An estate roof is made of factory trusses at regular spacing, and those are a structural system that cannot simply be cut. A farm conversion lies somewhere between the two, with large members and an insulated lining that need to be understood before a frame is chosen.

A terrace roof can be opened up and trimmed, whereas a truss roof has to be worked around.

Flat roofs are the common thread. Extensions to terraces and semis, garage conversions and porches all carry flat or near-flat roofs, usually in felt or single-ply, and these are the places where a rooflight can be dropped in without touching the main pitch. That makes them the first place we look when the aim is simply to bring light into a kitchen or a downstairs room. Garages tacked onto the side of a semi often have a shallow-pitched or flat roof that has not been touched since it was built, so those are worth a look from the loft hatch as well. A flat rooflight is also the easier job to price, since the deck is open to inspect from above and the upstand can be built to suit.

Many Astley addresses carry a Manchester postcode, and the village lies in Greater Manchester, but the planning authority is Wigan Council and not any of its neighbours. That matters when you look up a rule or an application, because the council that handles the application is the one that holds your address on its map. A pitched-roof house will usually need no application for a rooflight; the conditions behind that are written up once in when a skylight needs planning permission, and we run them against your roof before quoting.

Flats are the main exception, and so are properties where the council has issued an Article 4 direction. We ask about both when you contact us. The older buildings need a closer look. Listing covers the colliery headframe and winding house, two moated halls and a few old farmhouses and a barn, and for any of those you apply for consent before cutting the roof; how consent works for a listed roof walks through it. Historic England holds the national list, and the council's conservation officer is the person who will read your drawings, so a clear photograph of the roof and a sketch of the unit help a decision along.

On a loft conversion in an estate house, the front slope is the one to think about. A unit facing the street can become a planning matter, which the rules for a front-slope roof window explain, while choosing sizes for a loft room deals with positions.

We send the Building Control notification for every Astley rooflight to Wigan Council or a registered building control approver, and what that inspection checks is laid out in a separate guide. From first call to sign-off, a job in Astley moves through four stages.