Can a VELUX be electric?

Every VELUX roof window falls into one of three groups, and it helps to know which one you are talking about before anyone quotes you.

The first is manual. You open it with a bar or a handle, either directly if you can reach the sash or with a telescopic pole if it is out of reach. There is no motor and no wiring. It is the cheapest option and the one most houses already have.

The second is mains electric, which VELUX sells under the INTEGRA name. A motor is built into the top of the sash, powered by a cable run back to your household electrics, and you open and close it from a wall switch or a handset. An integral rain sensor shuts the window automatically the moment it detects water, so a sudden shower while you are out does not leave the room open to the weather.

The third is solar electric, also branded INTEGRA. It works exactly like the mains version, with the same motor, the same rain sensor and the same controls, but the power comes from a small photovoltaic panel on the outside of the frame that charges a battery hidden in the sash. There is no cable to run and nothing to connect to your consumer unit. That makes it the usual choice when a window is already in and you want motorised opening without lifting floorboards or chasing a wall.

The motor is not the point in itself. What you are really paying for is the jobs it does without you.

• Windows you cannot reach. High in a vaulted ceiling, over a stairwell, or above a kitchen run where you would need to stand on the worktop, a motorised window is the difference between a room you can ventilate and one you leave shut. This is the most common reason people ask for electric in the first place.
• The rain sensor. A manual window left ajar for airflow is a gamble against the forecast. An electric one closes itself, which matters more on the estuary than inland, because weather comes in fast off open water and a shower can arrive before you have crossed the room.
• Programmed ventilation. INTEGRA units can open on a timer or a schedule, cracking the window for a few minutes to clear cooking steam or morning condensation and closing it again. For a bathroom or a deep kitchen that is genuine day-to-day use, not a gadget.
• Grouped control. Where a room has two or three roof windows, one handset can open and close them together, which is tidier than working round the room with a pole.

None of this changes how much daylight or heat the window lets in. A motor moves the glass; it does not alter what the glass does when it is shut, and on a bright roof that distinction matters, which is the next section.

This is worth saying plainly, because it is where money gets spent in the wrong place. A motor helps you get hot air out of a room. It does nothing to stop the sun heating the room up in the first place. Those are two different problems, and on a south-facing roof the second one is usually the bigger of the two.

Southend faces south across the Thames Estuary, so a great many rear extensions and loft conversions here point their glass straight at the sun for most of the cooling season. On a clear summer day the sun delivers something in the region of 800 watts to every square metre of well-oriented glass. If that glass is standard clear double glazing with a G-value near 0.6, most of that energy ends up as heat in the room, and no amount of opening the window at the top will keep pace with it through the afternoon. Reflected light off the water adds to the load and makes the room glary as well as warm.

The fix for that is the glass, not the motor. Solar-control glazing with a G-value around 0.3 or below turns away roughly half the heat before it enters the room, and you can specify it on a manual window, a mains INTEGRA or a solar INTEGRA without changing anything about how the window opens. So the sensible order is glass first, opening mechanism second. Decide what specification the roof needs on orientation and glazed area, then decide whether you want to open it by hand or by motor. Our energy-efficient skylight installation work is built around exactly that reasoning, and electric opening sits happily on top of it once the glass is right.

Electric ventilation does still earn its place. A window that opens on a timer to purge warm air overnight, or one high in a vaulted room that you would otherwise never open, is doing useful work. It is just the second line of defence, behind the glass, rather than a substitute for getting the specification right.

If you are starting from a manual VELUX and want it motorised, you do not necessarily need a new window. VELUX sells conversion kits that add a solar motor, the rain sensor and a control to an existing window, provided the window is a compatible model and roughly the last decade or so old. The solar kit is the straightforward one, because it carries its own power and needs no cabling. A competent installer can fit it in an afternoon.

Mains electric is a bigger job on an existing window, because the cable has to reach the sash from your household supply, and that often means running it through the ceiling void and having the connection made by a qualified electrician under Part P of the Building Regulations. If the window is going in as part of a new opening, or a loft is being converted anyway, the cable route is easy to plan in and mains is worth considering. On a window that is already sitting in a finished ceiling, solar usually wins on disruption alone.

A few things worth checking before you commit:

• Model and age. Retrofit kits only fit certain VELUX generations. The data plate inside the frame tells you the model and year, so note it down before you order anything.
• Reach for maintenance. Even a motorised window needs its filter and sensor kept clear. If it is genuinely unreachable, factor in how you will clean it.
• Battery life on solar units. The battery in a solar INTEGRA is a serviceable part and lasts years, but it is not permanent, so treat it as something that will eventually be swapped.

Replacing a failed or dated window with a new electric one is a clean way to gain motorised opening and upgrade the glass in the same visit, since the opening and the flashing are being disturbed anyway and the only real decision left is what unit goes back in. That sits within our VELUX window installation service, and it is the moment to get the G-value right rather than default to whatever clear glass comes as standard.

Work out three things about the window before you ask anyone for a price: which way the roof faces, whether you can reach the window from the floor, and how easy it would be to get a mains cable to it. Those answers point straight at the right option. South-facing and hard to reach argues for solar electric with solar-control glass. North-facing and within pole reach may not need a motor at all.

If you would rather we worked it out with you, tell us the orientation, the rough size of the opening and whether the window is new or a replacement, and we will come back with a glass specification and the opening options that suit it. Ring 01702 898232 or request a quote, and we will look at the whole roof rather than just the window in it. For a sense of where the numbers land, the electric skylight installation page sets out what motorised opening adds.