"I Put Up Secondary Glazing on My Old Sash Windows Myself Every Year — These Are the Things I'd Tell Anyone Else Who Wants to Do It"

I'm sure you've had more than enough weather chat over the past few weeks, but just in case you weren't utterly bored by it yet, let me just say... Gosh, it's cold out. And when I say out, I mean everywhere. Including inside my home, much to my chagrin. Which is exactly what led me to start thinking about secondary glazing.

Okay, that and this Instagram post I happened to stumble upon. You see, unlike me, interior designer Dan Lovatt had actually decided to do something about the cold spots caused by his original sash windows. Until I saw his post, secondary glazing was a task I believed was best left to the professionals. But, as Dan has proven, I was mistaken. So I set out to learn more about this clever DIY window treatment.

Unlike double glazing, secondary glazing doesn't require you to remove your original windows; instead, you simply add another layer to them. It's a budget-friendly, effective, and completely reversible way to amp up the insulation of your windows, keeping your home warmer through the winter months. It's an especially useful addition to period homes, as it allows you to maintain original features, while also helping to protect you against the cold. And, as I've learnt, it's pretty simple to do yourself, too. Sound appealing? Well, I asked Dan to share everything he's learnt along the way, as well as what he wished he knew before, so we can

What Does Secondary Glazing Do?

Before you make any decisions, it's important to understand the circumstances in which secondary glazing is helpful, and when it's not, because this isn't a one-size-fits-all solution.

If you're wondering whether your property is suitable for this treatment, start by considering the period your home was built in. Secondary glazing is particularly useful for period properties, so if your home is Edwardian, Victorian, or Georgian, this is a great option for you. But, truth be told, any home with single glazing could likely benefit from this winter window treatment.

For Dan, the main issue he wanted to tackle was his fragile, drafty windows, which were prone to rattling through the winter months. "The seals aren’t great on them; they definitely need maintenance. However, this is something to help insulate living rooms during the winter months, stop those drafts coming through, and provide that extra layer of insulation."

Prior to installation, Dan made time to acquaint himself with the other options out there before ultimately committing to secondary glazing. "There are other alternatives, like films that you can apply with a hairdryer that stops any drafts coming through, but I don’t think they are as robust as secondary glazing." You can find kits like this on Amazon.

Everything You Need To Know Before Second Glazing

Next, you'll have to decide whether you'd rather go with a professional or if this is a home DIY project you feel prepared to take on directly.

Generally speaking, this should be a relatively simple task, but if you don't feel confident in your own skills, it might be wise to involve a friend or partner. Plus, a second pair of hands can come in handy when it comes to the more strenuous or fiddly parts of the process. Dan mentions that, despite his research, this still caught him by surprise; "I wish I knew that the sheets can be quite heavy, so fitting them on your own can be awkward."

However, before you can even get started with your installation process, you'll have to pick out your glazing sheets — and this can be trickier than you may expect. "You definitely need to get the glazing where it sits, probably about 2 to 3 centimeters (if you have that clearance) away from the window, so you have enough space to put a magnetic strip on," advises Dan.

This is a task in which it pays off to be exact, no haphazard guesses or estimations here. Take the time to use an accurate measuring tape, and don't shy away from double-measuring to ensure you've not made any mistakes. Learn from Dan, who says the biggest challenge he encountered was "The measuring to make sure there was enough space, that you had a good amount of space for a magnetic strip to sit in the window discreetly, and also double measuring to make sure it was before it was done."

While it may be a relatively simple task, this doesn't mean it's one you can rush through. Take your time and be patient throughout the process. "When you are applying the magnets to the window to apply the secondary glazing, pull the tape back slowly so it doesn’t all fit at once, as it can get stuck, which is hard to get back off," recommends Dan.

The Results

And once it's all done?

"The living space definitely is more insulated," admits Dan. "It retains the heat a lot better. There’s no drafts coming through that space. So all around, it’s great for those winter months when you’re not opening your windows as often."

It's a relatively quick way to make a cold room feel warmer, and it isn't too expensive either, if you've got the DIY skills. Plus, it should keep you from cranking up your heating to full blast, so, in the long run, it will save you on your energy bills.

Of course, though, you can't let these toastier conditions make you forget how often to open your windows during winter. Dan reminds, "You still should be airing your property out every other day to help get rid of stale air, but otherwise, it’s made it a lot warmer in there."

Adding some extra insulation to your windows can do a fair deal when it comes to improving the temperature conditions of your home. But, if that still doesn't feel like quite enough, why not try out some of our other ideas on how to winterize your home.