Skylights & Rooflights in HorsforthLight for the stone terraces and family semis of north-west Leeds

Horsforth grew in layers, and you can read the layers in the rooflines as you walk from the older streets out to the edges.

The oldest part of the suburb has stone-built terraces and cottages under slate. Around them came inter-war semis in brick or stone, with hipped or gabled roofs and rear slopes that suit loft rooms. Later came the 1960s and 1970s estates, with concrete tiles, lower pitches and often a garage or flat-roofed extension attached. Many of those houses have since been extended again.

Each layer wants something different from the glass, and the table below is how we usually think about it before visiting.

Horsforth sits inside the Leeds City Council area, so that is the authority to ask when a roof raises a planning question.

For most houses, a roof window or low rooflight is permitted development, provided it passes the tests in our skylight planning permission guide. Three situations change the answer. Flats and maisonettes need an application. Listed buildings need their own consent. And in a conservation area, an Article 4 direction on a particular street can take the right away. Leeds has a number of conservation areas, so a quick check of your address is worth doing before you order anything.

Lanterns are a separate case. Because they usually rise well past the low height that permitted development allows, a lantern on an existing extension tends to need an application or the council's written view first. A lantern drawn into a new extension is judged along with the build, which eases the timing.

In a suburb as built-up as this one, the first question is often not whether the council minds but whether the back garden next door can see in.

From a survey in Horsforth

A stone house with a slate roof rewards a gentle approach, because old slates split when they are rushed.

When we open a slate roof for a window, we lift the slates by hand and put the sound ones aside for refitting. Any that crack are replaced with the closest match to the rest of the roof. The flashing kit is chosen for slate so it lies flat and tight rather than standing proud, and the frame is set so the glass sits low in the roofline.

Because older roofs are rarely perfectly true, we take measurements from the roof itself rather than from drawings or the street. These houses often have shallow loft spaces under a modest roof, so a roof window may be there to light a landing or a small study rather than a full bedroom. Three measurements settle the size: the sill height, the head height and the rafter spacing. Between them they show which window fits without cutting more structure than the room needs.

The rear slope of a Horsforth semi is where daylight tends to be won, because it is out of sight and usually faces the garden.

A loft that has been boarded and lined is only a good room if it has windows worth sitting under. Two roof windows set side by side spread the light across the floor and give you a view when you are standing as well as sitting. A single window can work in a small box-room. Where a blind is wanted for summer evenings or a child's bedroom, it is easiest to plan the fixing at the same time as the window. The choice between top-hung and centre-pivot comes down to the pitch and how you will use the room.

If the loft is becoming a bedroom, the question of escape needs an honest answer. Approved Document B limits escape windows to floors no higher than 4.5m above the ground, and a two-storey house puts its loft above that. The answer there is a protected stair, so the roof window is there for light and air rather than as a way out. We would rather say so at the survey than let it become a surprise with Building Control.

Our roof window installation page covers the sizes and opening types in more detail.

An extension with light at the garden doors and shadow near the old back wall is the classic Horsforth rooflight job.

Plenty of semis in the suburb have a kitchen or dining room pushed out into the garden. The new room gets its light from the far end, so the part nearest the house stays gloomy. A flat rooflight or lantern over that middle band fixes it. Either one sits on an insulated upstand, and that upstand should normally rise at least 150mm clear of the finished roof surface.

Before we put a price on it, we find out what the roof is built from and how it drains. A tired felt roof is best re-covered around the new opening, while a sound rubber or GRP roof can usually be formed up to the upstand cleanly. See flat roof rooflights for the options.

Some rooms have no outside wall and no roof slope above them, and a sun tunnel is the way to reach them.

Houses built in the middle of the last century often put the bathroom or the stair landing in the centre of the plan. A sun tunnel takes daylight from a little dome outside, along a mirrored tube, to a diffuser overhead. It is best for somewhere you pass through or use briefly. A room where you spend hours generally deserves a proper window.

The sun tunnel installation page explains what is involved.

Most Horsforth jobs are done in a home that is still being lived in, so the running order of the days is as important as the choice of glass.

Before we start you are told what each day holds. Floors, stairs and furniture go under covers, the working area is screened off where we can, and the roof is closed to the weather before the team leaves each evening. One team sees the job through from first cover-up to final sweep, and the waste leaves with us. The concealed parts, trimmers, upstands, flashings and insulation, are built carefully and photographed for you.

Horsforth is about 29.4 road miles west of York, at the western limit of what we cover, and the survey costs nothing.

At the survey we measure the room, check the roof inside and out, and talk through the planning position, including who at the council would need to be asked. A written quote follows, itemised line by line, along with a plan for each day. If the work is notifiable, the Building Control notification is ours to arrange. At handover you receive the makers' warranties, any Building Control paperwork, and a 10-year workmanship guarantee.

Because the journey from York is long, we plan a Horsforth survey for a set window and tell you the arrival time in advance. If the loft is already boarded or full of boxes, a little clearing beforehand lets us see the rafters and the underside of the roof covering properly, which is where most of the useful detail is found.

Nearby, we also work in Bramhope, Pool in Wharfedale and Leeds. Sending the form below is the simplest first step.