Garage heating and lighting questions

[SomeoneElsesOpinion]

We have an integral garage (I think that’s what it’s called - where the door to the garage is from the hallway in our house). We use it for storing spare shoes, bikes, DIY stuff, home admin type stuff including our printer etc. The house is new build and beautifully warm but (now the weather is cold) the garage is absolutely freezing! Would it be a total waste of money to have a low level heater in there just to take the edge of the chill off? If so what would be a good thing to use? We have power in there so plugging something in isn’t a problem but don’t want it to cost a lot to buy or run.

The second Q is that the garage has spot lights on the ceiling and the light switch is in our hallway. Children often switch the lights on when they go in for shoes etc and forget to switch it off. We can’t tell it’s been left on so I can be left on for a couple of days before we open the door and notice. Can we cheaply fit a sensor or timer to the lights?

You can get cheap buttons where the light stays on for a few minutes, common in corridors of flats. Or you can use a pir sensor to switch it off again. Also cheap, simar to outdoor lights.
Alternatively you can change the switch to one that has an indicator, although you would need a neutral connection at the switch for that.

Regarding the heat, the reason your house is warm is due to the insulation not due to the heating alone. You would have to add insulation too if you want to make a significant difference.

Is the garage inside the structure of the house so that it has cavity walls and a room above?

If so, you could use insulating foam boards on the garage door which would make a big difference

However, if it has its own uninsulated roof, it can lose more than 3kW of heat through that on a frosty night, so anything you spend on heat will only comfort the pigeons.

delay switches

Another trick might be to wire an additional lamp to the garage lights, that comes on when they do, and is mounted in the hall, above the garage door.

But if you have LED or energy saving lamps, the running cost is insignificant.

(why would anyone want spotlights in a garage?)

Maybe spotlights is the wrong term. Here’s a pic. They are modern lights/bulbs so I don’t worry if cost of them being on is insignificant! That’s a good point!

Re the heat (cold!) issue. No idea about the roof of garage. Here is pic from back of the house. The window facing you is the garage. As you can see it has a slanted roof. There is a HUGE amount of insulation in our loft. I’ll ask Mr S if that goes over the garage.

Yes above the garage ceiling there is space and insulation.

that's good!

If it has cavity walls and an insulated ceiling, the heat loss will not be intolerable.

The garage door looks as if it might already have some kind of insulation. See how thick it is. You're looking for a hard, rigid foam, probably covered in silver foil, and probably with a protective sheet over it. A plain door would be less than half an inch thick, if insulated, it might be two inches. You can sometimes add it to the inside of a door but yours is in hinged panels that might not be possible. You can work on draughtproofing though. Look out for "brush sealing strip" which allows doors to close through it, as each bristle bends out of the way.

Heating by electricity is very expensive.

If you have any pipes in there, consider a Tubular (pipe) heater under them. They are very cheap to run. I have one in my garage with a frost stat, it only comes on when the garage gets very cold.

If you hope to use the garage as an occupied room, you will need, I'd guess, more than 2kW of heat. I'd suggest an oil-filled radiator at each end. They are pretty safe as, unlike most electric heaters, they have no red-hot wire element, and get no hotter than a teapot. Fit timeswitches because somebody will forget to turn them off. This kind of switch will put a heater on for a limited period, and turns off when unattended. They are mostly intended for immersion heaters so you will need a 13A fuse in a plug or FCU as well.

If there is a radiator on the other side of the wall, you could have a plumber tee off through the wall for a radiator in the garage.

I'd be inclined, for economy, not to try to keep it warm. Wine-cellar temperature is fine.

Garages often contain paint, white spirit, rags, mowers, petrol, oil and other things making fan heaters and most convection heaters unsuitable. Include a smoke detector that sounds inside the house.