Do electric rooflights close automatically at night?

Out of the box, a mains or battery electric rooflight opens and closes when you tell it to. That instruction comes from a wall keypad, a handheld remote or a phone app, and nothing more. Left alone, it holds whatever position you last put it in. If you open it at four in the afternoon and forget about it, it is still open at midnight.

The one exception fitted almost universally is the rain sensor. Nearly every electric opening rooflight ships with a small sensor mounted on the frame or the surrounding roof. When rain lands on it, the motor drives the sash shut within a few seconds, whatever the time of day and whether or not anyone is home. That is genuine automatic closing, and it is the behaviour most people are half-remembering when they ask this question. It protects the room from a sudden shower, but it is triggered by water, not by darkness. On a dry, still night the rooflight will stay exactly as you left it.

So the honest position is this. Automatic closing when it rains: standard on almost all electric units. Automatic closing simply because it has gone dark: not standard, but straightforward to add.

If you want the rooflight shut every evening regardless of the weather, there are three routes, and which one suits you depends on how the unit is controlled.

• A timer built into the control system. The better electric rooflight controllers let you set a daily schedule directly, so you can tell the unit to close at, say, ten each night. This is the cleanest option because it needs no other kit, but not every basic controller offers it. Ask before you buy if a schedule matters to you.
• A smart-home hub. If the rooflight talks to a home automation system, closing at a set time, at sunset, or when the last person leaves the house becomes a simple rule. The same setup can close the unit if an indoor sensor reports the room has cooled to the point where ventilation is no longer wanted.
• An app on your phone. Many systems will send a reminder or let you close the unit remotely from bed, which is not fully automatic but covers the common worry of having left it open.

None of this is exotic. It is worth deciding at the specifying stage rather than afterwards, because the controller you choose determines what is possible. A unit sold with only a plain up-down remote will never run a nightly schedule, no matter what you add later.

Here is where the timing question stops being about convenience and starts being about comfort. Southend faces south across the Thames Estuary, and a great many rear extensions and loft rooms across south Essex collect sun from mid-morning until the sun swings west. Those rooms overheat in summer, and an opening rooflight is one of the best tools for shifting that heat, because hot air rises and a vent at the highest point of the room lets it escape.

The trick with an overheating room is to run the ventilation at the right time. On a warm night you often want the rooflight open, not closed, so the room can purge the day’s heat into the cooler night air. That is the opposite of the instinct to shut everything at bedtime. A well-set-up electric rooflight lets you have it both ways: open through the cool of the night to flush the heat out, then closed automatically before the morning sun and the day’s warmth arrive. Getting that sequence right does far more for a hot south-facing room than closing the unit the moment it gets dark.

Ventilation only takes you so far, though. If a room is genuinely baking, the glass specification is doing the heavy lifting, and the G-value of the glazing decides how much of the sun’s heat reaches the room in the first place. Airflow removes heat that is already inside; the right glass stops a large share of it ever getting in. The two work together, which is why we treat the opening mechanism and the glass as one decision rather than two. You can read how we approach the whole overheating question on our electric skylight installation page, and the solar-control glazing side sits alongside it.

A common worry is being caught out by a power failure with the rooflight open. Behaviour varies by system, so it is a fair thing to ask about. Mains-powered units generally hold their last position during an outage and simply wait for power to return; they do not drift open or slam shut. That means the rain sensor cannot drive the unit closed while the power is off, which is one argument for the battery-backed or solar-powered controllers that keep the safety function alive independently of the mains.

Two more points are worth checking on any electric opening rooflight:

• Manual override. There should be a way to move the sash if the electronics fail. On most systems that is a secondary control or a manual release, so a fault never leaves you unable to shut the room up.
• Obstruction sensing. Good controllers stop the motor if the sash meets resistance on the way closed, which matters if a blind, a plant or a cat gets in the way. It is a safety feature rather than a scheduling one, but it belongs on the same list of questions.

If your existing electric rooflight has stopped responding altogether, that is a job for whoever supplied the motor or an electrician, not something to force. Where an older unit is coming out because the glass or the frame has reached the end of its life, the replacement is the moment to move to a controller that can do the scheduling you want.

Decide two things before you buy. First, do you actually want a set nightly closing time, or is the rain sensor plus a phone reminder enough for how you live. Second, is the room one that overheats, because if it is, the useful question is not just when the rooflight closes but when it opens, and what glass sits in it.

If you tell us the roof orientation, the rough opening size and whether the room runs hot, we will come back with an opening rooflight specification, a control option that matches how you want it to behave, and a price. Ring 01702 898232 or request a quote, and we will look at the whole room rather than just the switch on the wall.