Rooflight and Skylight Questions Checklist

Write down the rough form of the roof over the room — flat, a single slope, or two slopes meeting at a ridge — and which way each slope faces.

Roof form and orientation narrow the sensible options very quickly, and being able to describe them saves an early visit being spent on basics.

Note what the covering looks like from ground level — small overlapping tiles, large profiled units, slates, or a continuous membrane — without assuming what sits beneath it.

The visible covering shapes how an opening would be weathered, but what lies under it often differs from what an owner expects.

Record whether the space above the ceiling is reachable, and whether anything is boarded, stored or built into it that an opening might displace.

Openings are frequently wanted exactly where a water tank, a boarded floor or a run of boxes already sits.

Photograph any staining, damp patches or repair marks on ceilings, around chimneys and at wall junctions, and note when you first saw each one.

Existing marks change the conversation from adding an opening to understanding how water got in, and that history is worth capturing before anyone visits.

Causes of damp and leaks have to be established on site by a qualified professional; do not assume new work will resolve or worsen an existing problem.

Describe how insulation currently sits — laid over the ceiling, packed between joists, or held against the slope — as far as you can see without disturbing it.

Where insulation sits determines which surfaces stay cold, which is central to any later discussion about an opening and condensation.

Insulation position affects moisture risk in ways that are not obvious; ask a qualified professional rather than moving or adding material yourself.

Write down which neighbouring windows look onto the slope you are considering, and which of your rooms would become visible from them.

Overlooking through a roof opening is easy to miss on a plan and awkward to resolve once the frame is set in place.

Note which parts of the day the room is used most, and whether electric light is switched on then even when it is bright outside.

The times lights go on during the day usually point straight at the part of the room that needs help.

Record which walls of the room have no realistic window option, because of a boundary, a stair, a chimney breast or a fitted run of units.

Ruling walls out is what makes a roof opening the sensible answer, and it is useful evidence for the discussion.

Map where desks, screens, seating and beds sit in the room, and say whether direct light onto each position would be welcome or a nuisance.

Light from above falls on surfaces a side window rarely reaches, so the furniture layout tends to matter more than people expect.

Note whether the room is used for sleeping, and whether early light or nearby street lighting reaching the ceiling would matter to whoever sleeps there.

Consider whether the landing, stair or corridor beside the room is also dark, and record that, since a single opening sometimes serves more than one space.

Describe the light you want in plain words — even background light, a bright patch to work in, or a view of the sky — rather than naming a product you have seen.

A described aim lets a professional offer alternatives; a named product tends to close the conversation before it starts.

Decide and record whether the unit needs to open at all, or whether a fixed pane would do everything you actually want from it.

Fixed and opening units differ in detailing, operation and maintenance, so an early decision keeps later conversations focused.

Note how far above the finished floor the opening would sit and whether anyone could reach it standing on the floor without steps or equipment.

Reach decides whether an opening gets used daily or is opened once and then left alone, which changes what deserves attention in the brief.

Ask who is responsible for deciding the operating method — pole, crank or powered — and what a powered unit would need from the electrical layout.

Any power supply serving a roof opening is work for a qualified electrician; agree who arranges it before the position is fixed.

Write down whether you expect the opening to provide ventilation in warm weather, and raise with a qualified professional how that sits alongside the rest of the room.

Owners often assume an opening solves stuffiness, when air has to be able to enter somewhere else for anything to move.

Consider how the glass would be cleaned on both faces, and note whether any part of the roof can be reached safely for that purpose.

Working at height is not an owner task; ask the installer and a qualified professional how cleaning and maintenance would be carried out.

Note whether blinds, insect screens or blackout are wanted, and ask which of those decisions must be made before the frame is ordered rather than after.

Fixings, recesses and cable routes for shading are usually decided with the frame, not once the unit is in place.

Record which rooms in the property already become uncomfortable on warm days, and whether the room under the proposed opening is one of them.

An existing pattern of overheating is the strongest signal that shading and opening strategy need attention from the start.

Note what shades this roof at present — a tree, a taller neighbouring building, a chimney — and whether that shading is within your control.

Shade provided by something you do not own or could later remove is worth flagging, because the room may behave very differently without it.

Write down whether the slope faces towards the strongest afternoon sun, using the compass on a phone if you are not sure of the orientation.

Ask a qualified professional how glazing choices, external shading and opening size interact for this particular roof, instead of selecting glass from literature alone.

Thermal and shading behaviour depends on the whole build-up, the orientation and the room; only a qualified professional can weigh it for your roof.

Note where radiators, cooking areas and other heat-producing appliances sit in the room below, since they add to how the space feels on a warm day.

Record what other ways the room already has of losing heat, such as an opening window or a door onto a cooler space, and note whether they are used.

Air moving through a room needs somewhere to leave as well as somewhere to enter, and existing openings are part of that picture.

Note where rainwater currently leaves the roof and where gutters and downpipes run, so any proposed opening can be discussed in relation to them.

Water paths across a slope are fixed by the existing geometry, and an opening placed without regard to them creates problems that are hard to correct.

Mark on a simple sketch where the opening would sit relative to a ridge, valley, hip, chimney or an abutting wall, even if the sketch is rough.

Junctions are where roof detailing becomes demanding, and a professional treats an opening near one very differently from one in open tiling.

Ask what upstand, kerb or flashing arrangement an opening would need with your covering, and record the answer rather than assuming a common detail applies.

Weather detailing varies with covering type, pitch and exposure; only the supplier and installer can settle it for your roof.

Record whether snow, leaves or moss tend to collect anywhere on this roof, and note the parts of the slope where they sit longest.

Ask whether existing tiles or slates can be lifted and reused around a new opening, and what would happen if matching units could not be found.

Matching an older covering is often the practical constraint on how an opening looks once the work is finished.

Write down any condensation you already see on window frames, reveals or cold walls elsewhere in the property, since the same pattern may appear at a new reveal.

Condensation has several possible causes; ask a qualified professional to consider ventilation and construction before anything is ordered.

Note the direction the visible timbers run and roughly how far apart they appear, treating your own measurement as a description rather than a finding.

Even an approximate description helps a professional anticipate what an opening would involve before they attend.

Record whether the roof appears to be formed from prefabricated frames with diagonal members or from individual timbers, and say plainly if you cannot tell.

Whether any roof timber can be altered is a structural question; ask a qualified professional and record their instructions before work is planned.

Write down which services you can see in the roof space — pipework, cabling, a tank, an extract duct — and roughly where each one runs.

Services running exactly where an opening is wanted are one of the most common reasons a position has to move.

Ask who will establish what the framing allows and what altering it would involve, and record which party is taking that responsibility in writing.

Do not proceed on an assumption about the roof structure; a qualified professional must assess it and set out what is needed.

Note what is stored in the roof space that would have to be moved, and where it would go while any work is under way.

If more than one opening is being discussed, record how they would relate to each other along the slope and whether you want them aligned with anything below.

Alignment with rooms, walls and existing windows reads strongly from outside, and it is far easier to consider now than later.

Ask how access to the roof would be arranged and whether it would affect a neighbour, a shared path, a driveway or a garden you do not control.

Access over land you do not own has to be agreed with that owner; treat it as a matter for the neighbour and your professional advisers.

Write down whether the roof covering is likely to be renewed anyway, since the order in which the two pieces of work happen is worth agreeing early.

Forming openings during a wider recovering usually changes what access and making good involve, so the sequence deserves a deliberate decision.

Record who takes the final site measurements for the opening, and what happens if the measured size turns out to differ from the drawn size.

Note who is responsible for forming, boarding, plastering and decorating the internal reveal, because this often falls between two different parties.

The reveal is the part the household looks at every day, and it is the item most often left out of both scopes of work.

Ask what the product warranty covers, what conditions it depends on, and what registration or records the supplier expects after the unit is fitted.

Write down what routine maintenance the unit is expected to need and who in the household would realistically carry it out.

Seals, hinges and drainage channels on roof openings need attention, and an honest answer now may change which option suits you.