Tile roofs over East Ardsley's semis and bungalows, with skylights and rooflights to suit

Telling the roofer about the opening

If one firm strips the roof and we fit the window, the two jobs have to meet in the right order. The roofer needs to know where the opening is and how big the unit will be, so that the battens are not nailed straight across the gap. A few minutes with the plan and a tape on the roof avoids lengths of timber being cut twice.

A window in a roof that stays as it is

A roof in sound condition does not need to be re-tiled for a window. The work is done from outside, across the slope, so the weather on the day matters more than the state of the house. Tiles around the opening are lifted, set to one side and laid back against the flashing as soon as the frame is fixed. Any tile that breaks on the way off is swapped for the nearest match available, and the weathering is checked before we leave the roof.

Where tiles are slipping or the battens look tired, it is worth raising before any new opening is cut. A window set in a roof that is about to be renewed often ends up being lifted again, so the order of the two jobs is worth settling early.

Hipped ends over the landing

Some semis have a hipped end, where the roof slopes down on three sides over the landing. A hip is a short slope, and the opening must sit clear of the hip rafter. A smaller unit may suit the short slope better, and so may a sun tunnel.

Flashing for an interlocking tile

A tile with a deep profile leaves gaps along its edge, and the flashing has to fill them. The kit comes in a version for each tile profile: an apron at the bottom, soakers along the sides and a gutter across the top. Together they guide water coming down the slope past the frame and back onto the tiles below it.

The reveal inside

On the ceiling side, a splayed lining runs from the window up to the room below. That reveal is insulated, plastered and finished in the room, which is the stage that settles whether the window looks like part of the house or a hole in the ceiling. A light well with sloped sides, wider at the bottom, spreads the daylight into the room rather than dropping it in a narrow shaft.

Dust sheets on the stair

Cutting through a plaster ceiling makes fine dust, so the floor and the stair beneath the opening are sheeted before the work begins. Once the reveal is done the sheets are lifted and the rooms wiped down. In a semi with a single stair, that keeps the dust out of the bedrooms and the hall.

The glazing standard and the way the window opens

Under Part L a new roof window must reach 1.4 W/m²K or earn band B on its Window Energy Rating, and a rooflight must reach 2.2. The choice that remains is between a centre-pivot window, which swings on a pin at its midpoint so that a bed or desk has to stay clear of its lower half, and a top-hung one, which hinges at the head and pushes out, leaving the space beneath it free.

Planning is a separate question. The full conditions for a house are set out in the planning and regulations guide, and East Ardsley sits in the Leeds City Council area.

Which side of the roof the window sits on

For a landing over the stairs, the rooflight tends to sit wherever the stair does, which puts it nearer the middle of the house than the front. A window on the back slope is less visible from the road and picks up sun later in the day. A front slope window faces the street and, in the morning or evening, can add a little more light on the stair.

Matching the frame colour to the existing windows keeps the front elevation calm, and a single unit looks better than two small ones.

Sizes that stay in proportion

VELUX codes pair a letter for the width with a number for the height, so MK04 and CK02 are different shapes. On a short front slope a wide, low unit often looks better than a narrow, tall one, and it is easier to keep clear of the ridge.

The top of the window may not rise above the ridge. On a low bungalow roof that limit is closer than owners expect, and we measure it on the day.