Horsforth skylights and rooflights for gritstone terraces and the semis behind them

Roof window or sun tunnel

A roof window suits a landing or attic room that sits directly under the slope, including a stair that climbs into the roof space. Where there is a loft hatch and clear loft above the middle of the first floor, a sun tunnel carries daylight down a reflective tube to a diffuser set in the ceiling. A tube slips between joists, and each case is judged on the route it needs.

Front slope or rear slope

On a terrace the front slope faces the street and the rear faces the yard. The rear is usually the better choice, since it leaves the face of the house as it was built and keeps the planning position straightforward. Whether a rooflight needs an application turns on how far it stands off the slope and whether the house is listed, in a conservation area or divided into flats, and the planning guide goes through each condition.

Slate on the old rows, tile on the newer ones

The older terraces carry slate and the later semis carry concrete tile. Slate is thin, so its flashing kit is cut for a flat profile. Tile is thicker and moulded, and takes another kit entirely. Either roof can be worked from the outside, by lifting the covering around the marked area and relaying it up to the frame.

What fitting day looks like

We strip the covering from the marked area, frame the opening between the rafters, set the unit into its flashing, close the ceiling and plaster the reveal.

Furniture on the floor below is moved clear and the stair is sheeted, because cutting a ceiling sends plaster dust down every flight.

Getting materials in

Terraced houses have no side access, so the unit and its flashing come through the house or over the roof. We agree the route with you in advance, lay protection along it and carry everything in by hand. Long units are the awkward ones on a narrow stair, which is one more reason the size is settled in writing before anything leaves the supplier.

Glass that holds the heat in

Part L sets the thermal standard a replacement has to meet, and a single-glazed unit from the first loft conversion on the street falls well short of it. Modern glazing has two or three panes, a warm edge to each sealed unit, a low-emissivity coating and a thermally broken frame, so the attic loses less heat afterwards than it did before.

Odd sizes

An old frame of a standard roof window size takes a like-for-like unit and needs no change to the roof. An odd size leaves two choices: a unit that fills the gap with a slightly wider flashing, or a larger opening, which alters the roof structure and is a different job with its own quote.

Inside the attic

Old plaster around an attic opening can be crumbly, so the first job inside is to cut back to sound material before the new lining goes on. The splay of the old reveal shows how the lining was formed. We plaster it afresh, so the new frame meets a clean edge, and the floor and stair below are sheeted before any work above begins.

Does a lantern need permission

A lantern stands well proud of the roof, so it often falls outside the permitted development rule for roof alterations. Ask Leeds City Council, or look at whether the approved plans for the extension already show the lantern. The conditions are set out in the planning guide.

Where on the roof it goes

The middle of the roof is rarely the best spot. A lantern too close to the garden doors adds light where there is plenty already. Nearer the old wall it reaches the part of the kitchen that needs it. The joists matter as well, because the opening has to sit between members that can take the extra edge loads.

Aluminium or uPVC

Aluminium frames are slimmer and carry a bigger span. A uPVC frame is the cheaper route on a small lantern. The glass specification does more for comfort than the frame, and our energy efficient rooflights page lays out the options.

Glass for a south-facing lantern

A lantern over a kitchen that gets the afternoon sun can overheat the room. Solar-control glazing reflects part of the sun's heat, and a lantern with a blind or a tinted pane stays more comfortable at midsummer. Because the kitchen also needs winter light, the coating is chosen to keep the room usable in both seasons.

What the flat roof is made of

A felt, rubber or fibreglass covering each asks for its own upstand and weathering detail, so whatever already roofs the extension shapes how the kerb is formed. The kerb height and the way the membrane turns up it are settled before the lantern is ordered, because the unit has to sit on a kerb of the right size.