The frame that copes with steam
Over a shower the frame matters more than the glass: a white polyurethane VELUX is the one designed for rooms that are wet every day.
VELUX roof windows come in two main finishes. Pine windows have a lacquered timber frame and suit bedrooms, landings and studies. White windows have a timber core sealed inside a moulded polyurethane skin, and that skin does not take up moisture, does not need repainting and wipes clean. VELUX itself points the white polyurethane range at bathrooms and kitchens, and over a shower, where the inside of the frame meets hot water vapour twice a day and the odd direct splash, it is the sensible choice. Our comparison of VELUX window ranges sets out the two finishes side by side.
The lining around the window matters just as much. The reveals are formed in moisture-resistant board, taped and skimmed, and the insulation collar and vapour barrier collar are fitted so warm, damp air cannot reach the cold rafters behind. Leave those out and the first sign is a dark line of mould along the head of the reveal after one winter. The detail is covered in our guide to VELUX insulation collars and installation kits.
Ventilation: the window helps, the extractor does the work
An opening roof window is useful for clearing steam quickly, but a shower room still needs its own mechanical extract to meet Building Regulations.
Approved Document F asks for extract ventilation in any bathroom or shower room, typically an intermittent fan rated at 15 litres per second or a continuous system. A roof window does not replace it, because nobody opens a window on a January morning before a shower. What the window does well is purge: warm, wet air rises and collects at the ceiling, which in a loft shower room is exactly where the roof window sits, so opening the sash for ten minutes after a shower clears the room far faster than the fan alone.
Every VELUX sash also has a ventilation flap in the top bar that lets a little air through with the window shut. It gives steady background ventilation and helps keep the glass clear on cold mornings. How it works, and where it sits against Part F, is explained in do VELUX windows have trickle vents.
Where the sash goes relative to the shower
The position of the window against the tray decides whether it is a pleasure to use or something you duck under every morning.
A centre-pivot VELUX opens by swinging the bottom of the sash into the room. Directly above a shower that bottom rail can end up at head height, and the control bar at the top may be out of reach behind a glass screen. A top-hung window opens outwards from a hinge near the top and leaves the space underneath clear, with the handle at the bottom where it is easy to reach. Over a shower or a bath, top-hung is usually the better pick; a centre-pivot works well when it sits a little to one side, over the basin or the dry end of the bath.
Headroom follows the same logic. On a roof slope of 35 to 45 degrees, common on Cambridge terraces and 1930s semis, the ceiling drops quickly towards the eaves. Setting the shower where there is full standing height, and putting the window over that zone, gives both light and space. We draw this out with you at the survey, together with the size code that suits the rafter spacing, because the rafters often decide how far the window can shift.
Privacy, glass and blinds
A roof window looks at the sky, so privacy is usually easier than with a wall window, but overlooking from dormers and taller neighbours is worth checking.
On a rear slope in Romsey or Chesterton the only view in is often from the dormer of the house behind. If the window sits low on the slope, or a neighbour looks down on it, a blind is the simplest answer. Fabric roller blinds can stay damp in a room with a hot shower running; aluminium Venetian and pleated blinds tolerate humidity better and let you angle the light while keeping the view out. Our VELUX blinds guide goes through each type by room.
For the glass itself, a laminated inner pane is the standard specification over anyone standing underneath, so if the glass is ever broken it holds together. Our answer on whether VELUX glass is laminated explains the pane codes. Planning rules also matter on side-facing slopes: under permitted development, a side-facing window lower than 1.7m above the floor has to be obscure glazed and fixed shut. The limits are covered in do you need planning permission for VELUX windows.
The light a small wet room needs
Orientation shapes a shower room as much as a bedroom: a north slope gives even light for shaving and make-up, a south slope brings sun and heat into a small space.
Shower rooms are small, tiled and hard, so light bounces around them. A north-facing VELUX gives soft, shadow-free light across the mirror all day, which suits a bathroom better than almost any other room. A south-facing one fills the room with direct sun for a few hours around midday; in summer that warms a compact, steamy room quickly, and solar control glass or an external blind is worth considering. East is pleasant for a morning shower; west catches low evening sun and glare off the tiles. Our light planning page shows how each slope behaves through the year, and the VELUX window installation page sets out how we fit it. When you are ready, book a light survey and we will mark where the window, the tray and the light should go before anything is cut.
Questions people also ask
Will a VELUX over a shower get condensation?
Some misting on the glass after a hot shower is normal in any bathroom. It clears quickly when the extractor runs and the sash is opened for a few minutes. Persistent condensation on the frame or reveals usually points to missing insulation or vapour barrier collars, which are fitted as standard on a new installation.
Can water from the shower damage the window?
Splashes do no harm to a white polyurethane frame, which is sealed and wipes clean. Pine frames are less suited to water sitting on them every day. The glass and the frame are both fine with steam; the weak point is the lining, which is why moisture-resistant board and proper collars matter.
Can I replace an old pine VELUX over my bath with a white one?
Yes. A white polyurethane window can replace a pine one of the same size code, usually from inside with a replacement flashing. Our guide to replacing an old VELUX window explains what changes.
Do I need Building Control for a VELUX in a bathroom?
A new roof window in a new opening is normally notifiable, and a loft shower room also brings in ventilation and, for any wiring, electrical safety rules. We handle the Building Control notification where the work is notifiable, and a like-for-like replacement is usually simpler.
