Skylights and rooflights in Ashby de la Zouch

Ashby de la Zouch falls under North West Leicestershire District Council. Ashby is both a market town and a parish, sitting close to the Derbyshire and Staffordshire borders, and its castle was an important fort from the fifteenth century to the seventeenth. That history shows in the planning data. Ashby's conservation area was created on 2 November 1972, and the town centre point lies inside it. Within it, the register lists 139 buildings: 130 at Grade II, six at Grade II*, two at Grade I and one without a recorded grade.

Those numbers set the first job on any Ashby survey. A house that is neither listed nor a flat gets the benefit of Class C in the 2015 permitted development order. In plain terms the unit may project 150mm at the very most, cannot top the ridge, and on a side-facing slope needs frosted, fixed glass unless the section that opens lies higher than 1.7m from the floor. A listed building needs the council's consent before any new opening is made, and a flat carries no householder permissions of this kind.

A conservation area on its own does not shift Class C. Only an Article 4 direction, applied by the council to named properties or streets, can take it away. Whether one covers an Ashby address is the council's call, so check with them before you pay any deposit.

Where the register says listed, the product choice narrows fast. A conservation rooflight has a narrow frame with a single bar down the centre and lies flat with the slates or tiles, which is why conservation officers find it easier to accept next to a chunkier roof window. Even so, the decision is the council's, so we describe the proposal in terms an officer can take in at a glance: product, frame depth, position on the slope and how far it stands above the covering.

With 139 listings in one conservation area, a neighbour may well have been through this already, and it is worth asking what the council wanted from them. A proposal that answers the obvious questions up front, with clear photographs of the slope and a drawing of the opening, tends to keep the conversation with a planning officer short.

Bath Street holds a row of Classical-style houses called Rawdon Terrace, dating from the 1820s, when Ashby was a spa destination. The visible part is a polite brick street front. Elsewhere in the town an older structure is hidden by later brick facades, and that matters when someone wants a hole cut in the roof. What you see from the pavement tells you little about what is up in the roof void.

So we start in the loft rather than on the street. In an older frame the rafters may be hand-cut, irregularly spaced and notched where the roof was altered in a later century, and a purlin can run exactly where a window would otherwise go. We note where the timbers are sound, where the spacing allows a standard opening and where it forces a custom width. Only then do we name a product. A size chosen from the front elevation is a guess, and a guess in a listed building is an expensive one.

Ashby's industrial past was lighter than its neighbours'. There was a cotton textile factory and a glue factory, but the town was ringed by coalmines without ever being a mining town itself. Mineworkers working coal at Moira Colliery, three miles west, struck a heavy saline spring in 1805. The Ashby Canal was meant to serve the town from 1804, but it was built only as far as the village of Moira and never reached Ashby.

The canal is worth a second look from a roofing point of view, only because of what it did not do. A canal brings coal in and bricks out and tends to shape the housing along its banks. For us that means a street-by-street survey, not an assumption that one end of town resembles the other.

A loft bedroom brings in the fire question. Approved Document B recognises an escape window only up to 4.5m above the ground, so when the loft sits over two floors already, the way out has to be an enclosed protected stair. The roof window supplies light and air; the stair is what carries people out.

Allow about thirty-two minutes in the van to reach Ashby, which is 18.1 miles from Leicester by road, out towards the west-north-west. Bypasses have taken the heavy traffic that once came through town: the A42 relieves the A453 and the A511 relieves the A50, so the centre is calmer to work in. The closed station lies 0.5km from the centre. A survey here is a road trip, and we plan it so the morning goes on the roof and the afternoon on the drawing.

The town council has seventeen councillors representing six wards: Blackfordby, Castle, Holywell, Ivanhoe, Money Hill and Willesley. We use the ward names as shorthand when a customer tells us where they live, and then check the actual address against the register, because ward boundaries say nothing about when a house was built.

Three things decide most of what happens next. The age of the frame decides whether rafters are regular. The listing decides the paperwork. And the room underneath decides the product: a landing wants something different from a bedroom, and a kitchen different again. Ashby has plenty of each, so every quote here is written house by house.

Larger plots on the edges of town often carry a rear or side extension, and that is where a roof lantern earns its keep. A lantern is a glazed box lifted above the flat roof of an extension, letting light in from several faces, so a deep room that is dark at the house wall brightens evenly. Because it stands proud of the roof, we keep the height modest where a neighbour or the street will look at it.

A high stairwell or landing presents the opposite problem: a rooflight that nobody can reach. An electric opening rooflight solves that with a wall switch or remote, and a rain sensor that closes it when the weather turns. That is useful in a stairwell, where warm air collects at the top of a house and a small opening at the highest point lets it out.

The free survey starts outside, with the slope, the covering and the line of the ridge, and then moves into the loft to measure the rafters and see how the ceiling is fixed. A rooflight that suits a wide, shallow slope may be wrong for a steep one, so the pitch is recorded before any model is suggested. The written quote then names the product, the size, the glazing and the finish, with the installation and the making good included.