Skylight and rooflight installation across the hillside streets of Rawdon

A listed stone house

A listed house is different: listed building consent is needed before any rooflight goes in, and permitted development leaves that untouched. The application names the unit and where it goes. Conservation officers often ask for the slim black frame of a conservation rooflight on an older slate roof, because it sits low among the slates.

A street under an Article 4 direction

An Article 4 direction on a conservation area removes permitted development there, which is how one street ends up needing an application when the next does not. The slope facing the road matters most. If the room underneath can take its light from the back slope, that is where we start.

Slate that has been up there a long time

Older Rawdon roofs are slate, and later houses carry concrete tile. Old slate breaks easily; each slate round the opening comes off by hand, and the undamaged ones are relaid later. The frame gets a flashing kit shaped for slate, and cut slates above it overlap its upper edge, which sends rain over the joint and down the roof.

A stone house divided into flats

Flats sit outside permitted development for roof alterations. That usually means an application, so the council gets the first question. The lease names whoever must agree to work on the roof, which is often a freeholder or a management company.

Replacing a rooflight already in the roof

Fitting a new rooflight into an old one's opening leaves the surrounding roof alone, which a fresh cut cannot. The house is checked first all the same, since a listed one may need consent even for a straight swap.

Putting the answer in writing

With the position clear, the quote names the unit and its size along with the room it lights, and we notify Building Control whether the opening is new or reused. Should an application be needed, the council is asked about that one named unit.

Getting a long frame onto the roof

Where a garden falls away from the house, the extension roof stands higher above the ground at the far end than it does at the door. That changes where the scaffold goes and how a lantern frame, which is long and awkward to carry, is lifted up. We look at the fall of the garden, the side access and the width of the gate when we measure, so the lifting plan is settled before the day.

The kerb on a flat roof

A lantern sits on a kerb, a raised upstand built up from the roof deck. The covering is carried up the sides of the kerb to keep water off the joint, with a different detail for felt, for EPDM rubber and for GRP fibreglass. On an extension that is already built, the new upstand is matched to the covering on the roof. On one still being built, the roofer can form the kerb as part of the deck.

Lantern or flat rooflight

A lantern normally stands well above 150mm, which often takes it outside Class C of permitted development. The council can say whether one is covered, and so can the permission for the extension itself. A flat rooflight stays low on the deck and leaves the roof line alone, and our flat roof rooflights page shows when it is the better choice for a small extension.

What the lantern does for the old part of the house

The end of the kitchen beside the original back wall is where the daylight gives out. Glass overhead reaches it, and the light falls on the worktop and the table instead of stopping at the garden doors. A lantern also lifts the roof line over the room, so it needs to sit square to the extension and clear of the neighbour's wall.

Warmth in the kitchen

Glass on the roof loses heat faster than a solid roof, so the glazing matters. A thermally broken frame, warm-edge spacers and double or triple glazing all trim the loss, and the lower the U-value on the label, the smaller the loss.

Centre-pivot or top-hung

A centre-pivot unit swings on an axis through its middle, a good match for furniture standing under the glass. A top-hung unit hinges at the top and swings outward, which clears the headroom beneath it for someone standing at a shelf or standing desk. For a desk under a low eave, centre-pivot is usually the better choice.

Standing room and the stair

The window helps only if the attic can be used in the first place. The ceiling height at the desk, the loft stair and the floor all need to suit the use. If the attic is to become a bedroom, escape rules in Approved Document B apply; for an office they do not.

Glare and a blind

Daylight from above falls on the desk and often on the screen as well. A blind made for the window cuts the glare and the summer sun, and it is worth choosing with the window instead of afterwards. Out of reach above the desk, a window can be an electric opening rooflight run by a switch or remote, and our electric opening rooflights page covers them.

Which slope for the window

On a pitched Rawdon roof the rear slope usually keeps the window out of sight from the street, and the front slope faces the road. Where the desk sits under the gable end, a window in the slope nearest the desk puts the daylight where it is used. Rafter spacing limits the width of the opening, and a narrower window set higher in the slope can serve as well as a wide one.

Cutting into the rafters

Any new opening in a roof changes its structure. Trimmers, short lengths of timber, box in the opening between rafters and pass the load around it, so the window is sized to the rafters already in the roof. Inside, the lining of the opening is plastered to the agreed standard, so the room is ready to use.