Arc Fault Detection Devices (AFDDs): What Scottish Homeowners Need to Know in 2025

If you've had an electrician round recently, they might have mentioned something called an AFDD. Maybe you nodded along politely, wondering what on earth they were talking about. Well, you're not alone, these devices are relatively new to the UK market, and many homeowners haven't heard of them yet.

But here's the thing: AFDDs could be one of the most important advances in electrical safety we've seen in years, with recent changes to electrical regulations, they're becoming increasingly relevant for Scottish homes.

What is an AFDD?

Think of an AFDD (Arc Fault Detection Device) as a super-smart guardian for your electrical circuits. While your traditional circuit breakers and RCDs do a brilliant job protecting against overloads and earth faults, AFDDs go one step further. They're specifically designed to detect dangerous electrical arcs which are those tiny sparks that can occur when wiring becomes damaged or connections become loose.

These devices use clever microprocessor technology to constantly monitor the electrical "signature" of your circuits. When they spot the tell tale pattern of a dangerous arc, they shut off the power before things can escalate into something much worse, like a fire.

Should You Care?

Let me paint you a picture. You know that extension lead behind your sofa? The one that's been there for years, maybe got a bit squashed when you moved the furniture? Or those connections in your loft that haven't been checked since you moved in? These are exactly the kinds of scenarios where arc faults can develop.

In Scotland alone, electrical faults still account for a significant number of house fires each year. While we've made great strides with RCDs and modern consumer units, arc faults have been a bit of a blind spot – until now.

The New Regulations: What's Changed?

Here's where it gets interesting. Following Amendment 2 to the 18th Edition Wiring Regulations (which came into effect in 2022), AFDDs are now mandatory in certain situations.

For the rest of us? They're strongly recommended. And when electrical regulations use the word "recommended," it's worth paying attention – it often becomes mandatory down the line.

The Money Question

Right, let's address the elephant in the room – cost. AFDDs aren't cheap. You're looking at around £100 per device, and unlike some protective devices that cover your whole consumer unit, you need one for each circuit you want to protect.

But here's my take on it: we don't hesitate to insure our homes for thousands of pounds against fire damage. An AFDD is essentially insurance you only pay for once, and it actively works to prevent fires rather than just covering the cost afterwards.

Do You Need AFDDs in Your Home?

This is where it gets personal. While they might not be legally required for your property (yet), there are some situations where I'd strongly recommend considering them:

Peace of mind – Sometimes, it's simply about sleeping better at night knowing you've got the best protection available.

Installation: Not a DIY Job

I know some of you reading this are thinking, "Can I fit these myself?" Please don't. AFDDs need to be properly integrated into your consumer unit, tested, and certified. This is definitely a job for a qualified electrician – and in Scotland, that means someone who's registered with SELECT or NICEIC.

A good electrician won't just swap out your devices; they'll assess which circuits would benefit most from AFDD protection and might spot other issues while they're at it. It's also worth noting that many older consumer units simply don't have space for AFDDs, so you might need a board upgrade.

The Bottom Line

AFDDs represent a significant step forward in home electrical safety. Yes, they're an investment, but when you consider what they protect against, they start to look like pretty good value.

If you're planning any electrical work soon – maybe a new consumer unit, an EV charger installation, or a solar PV system – that's the perfect time to discuss AFDDs with your electrician. They can often be incorporated into the work more cost-effectively than retrofitting later.

And if you're a landlord or running an HMO in Scotland? Well, you don't have a choice – but hopefully, this article has helped you understand why that's actually a good thing.

Mackie Electrical - NICEIC-approved electrical contractors serving Central Scotland including Stirling, Perth, Falkirk, and Dunbartonshire. Specialists in electrical safety upgrades, consumer unit replacements, and AFDD installations.