A designer just taught me this inexpensive bathroom lighting trick that's changed my life for the better – it's an under $10 solution to my daily problem

I finished a bathroom renovation last year, and was pretty happy with all my choices for the lights. There was a flush ceiling pendant from Soho Home, shaded in pretty pressed glass, which refracted its glow around the room and stopped the light from seeming too harsh. And there were some wall sconces from the heritage brand Original BTC, which were just as soft in terms of the illumination they emitted. The entire room is bathed in soft light, perfect for wallowing.

But there was one problem with my bathroom lighting that I didn't even know was a problem, I thought it was just a fact of life. Every time I needed to go to the bathroom in the middle of the night I'd reach for my phone by the side of my bed, blearily fumble for the torch and stumble my way down the the hall, trying not to open my eyes too much for fear I'd not be able to go back to sleep. Then I'd open them properly anyway, trying to find the off button for my phone torch as I got back into bed.

I honestly just thought this bathroom lighting mistake was one that everyone had to deal with, and it didn't occur to me there might be a solution. Until I got chatting to the interior designer Lucy Barlow, co-founder of Barlow and Barlow, who gave me the answer I never knew I needed. It's super easy and super cheap.

Lucy and I were talking about bathroom lighting generally, preparing for a talk we were giving in the Original BTC showroom. She says that she doesn't always think practically when it comes to lighting ideas, that her brother – the other Barlow in her studio, Barlow & Barlow – deals with all of that, as he's a lighting designer by trade. But clearly his expertise has rubbed off on her, and she had a lot to tell me about the perfect bathroom lighting.

'Normally with modern lighting systems, you have scenes, pre-set,' Lucy was telling me. 'One bright one for doing your make-up, one for when you're relaxing in the tub and so on.' I'd not done that in my bathroom remodel, and oh, I wish I had added more types of bathroom lighting – but my lights are on dimmers and aren't too hard to adjust. 'And then of course I always use PIR sensors,' Lucy added.

PIR sensors? What are they? I am always listening out for new things in design I have yet to hear about. Was this some kind of funky new fixture?

'They're Passive Infrared Sensors,' Lucy schooled me. 'Electronic sensors that come on in the middle of the night when they sense movement, and will emit a very low level of light, so they don't disturb anyone and are less likely to wake you up fully than if you turn on the overhead lights.'

You mean, not everyone uses their phone torch?

Lucy just laughed. 'No Pip,' she said. 'They don't.'

Mind-blowing stuff, and while not a new design-led find, I was still very impressed. And after a bit of research, I found that PIR sensors are plug-in, meaning that unlike the scenes Lucy was talking about, you add them into your bathroom lighting plan at any time, super affordably.

They look a little like those plug-in air fresheners, and yes, I now have one in the hallway between my bedroom and the bathroom. Its glow is just enough that it reaches into the bathroom itself, meaning I don't have to turn on any overhead lights, and I can easily get straight back to sleep. I ordered one for under $10, next day delivery, and my life is hugely improved.

Shop PIR sensor lighting

I bagged a set of 4 lights for under $10, so adding these lights to your home is really affordable. However, there are different price points depending on what you are after. I wasn't so concerned with the style as they were at floor level and barely noticeabl,e but if you want them to line a staircase or entryway, there are designs that look more like traditional built-in lighting. These are a few of my favorites:

This might not be my usual tips on styling and aesthetics, but I appreciate a practical tip when I hear one. And I am going to invest in PIR lighting beyond the bathroom too, I am going to add one into my downstairs entryway for any late nights or early morning commutes when the overhead light is just too much, and one in my kitchen too, so I am not fumbling for a glass of water or mid-night cup of tea. Luckily, my purchase came in a pack of four, so I have plenty left over to dot around the rest of my home.