Slate over stone in Bingley, with skylights and rooflights for the valley's terraces and estates

The run through the loft

In a terrace the roof ridge often runs along the middle of the house, and the landing sits near it, so the tube can be short and nearly upright. If the landing is further from the ridge, the tube leans, and each bend costs some light. We work out the route in the loft and choose the position of the dome from there.

Between rafters and joists

A tube usually fits between two rafters and two joists without any cutting. Where a timber is in the way, the position can often move a short distance sideways to clear it. Cutting a rafter or joist turns the job into structural work, and the gap is then framed with trimming timbers.

Keeping the cold out of the tube

The tube passes through a loft that is much colder than the rooms below. A bare tube would cool the air inside it and let moisture condense, so the tube is wrapped or has insulation packed round it, and the joint at the ceiling is sealed. This wrapping is part of the job itself, and it matters more the longer the tube.

Dome and slate

The dome sits in a flashing made to suit the roof covering. On slate, the flashing is low and flat and the slates around it are cut to lie over its edge. On a tiled roof, the flashing has a profile to match the tile.

When a roof window suits the landing better

Where the loft above the landing is open to the stair, or the landing is wide, a small roof window can give a stronger result than a tube, and it also opens for air. We compare both on the day against the roof layout.

The wall that rises through the roof

Along the upstand, a lead or metal flashing runs between the stone and the slates, and the window needs clear roof on all four sides. A unit placed hard against the wall would crowd that flashing and leave no room to dress it. A gap of a hand or two is the usual result, and it is measured on the roof.

Shared stacks

Some terraces have a chimney stack at the party wall. It affects where a light well can run inside, because the flue and its breast take up space in the loft. Where the stack blocks the best position, a unit a little further down the slope can often serve the same room.

Why the middle of the slope is easier

Away from the wall, the rafters are on regular spacing and the roof is clear. A window set about midway along the slope has room on every side, and it lights the room beneath from a position that looks balanced from the street.

Looking along the loft

From inside the loft, the party wall is plain to see, and so is the line of the rafters. We stand in the loft to mark the opening before anything is cut, and the position on the slates is matched to it from the outside.

Your own slope only

The window goes in the slope above your own room, and the frame is set clear of the stone upstand so the neighbouring roof is left as it is.

Before the slates come off, the neighbours are worth a friendly word. Scaffold or a roof ladder will stand beside their gutter, and it is easier to explain a morning of noise than to apologise for one afterwards.

Trussed rafters and the opening

Roofs built in the last few decades may be framed with trussed rafters: factory-made triangles of slender timber, joined by metal plates, that carry the roof as a unit. The diagonal timbers inside each truss cannot be cut at will. An opening is possible between two trusses within their spacing, and a wider one needs a design by an engineer. We look in the loft and say which applies.

A planning condition from the day the estate was built

Some newer estates carry a condition from the original planning permission that withdraws permitted development rights. The planning history for the address, held by Bradford Council, shows whether one applies. We ask the question before a unit is ordered, since it would change the route for a roof window.

The bathroom at the centre

A bathroom in the middle of an estate house typically has an extractor fan and no window. It often lies directly under the loft, with a clear route to the roof between the trusses. That makes it a good candidate for a sun tunnel, and the tube is short because the ceiling is low.

The loft room

If the loft is to become a bedroom, a window set into the tiles brings it daylight and fresh air. The truss pattern sets how much headroom the room has and where the window can sit, so that conversation happens in the loft with a tape in hand.

Roofs with a mixed history

Streets that were built in stages can have more than one roof covering within a few doors. A stone terrace may sit next to a row of 1930s tiled semis, and the same unit needs a different flashing kit at each. We check the covering at the exact position of the window, whatever the rest of the street has.

Colour and finish

Concrete tile weathers and fades, and a new frame sits beside tiles that have been on the roof for decades. A dark grey frame is the usual match to a grey tile roof, and the flashing is finished to blend with it.