Own a period property and feel the chill every winter?
You are not alone. Thousands of homeowners throughout the UK own gorgeous Georgian, Victorian and Edwardian properties that are plagued with one issue… single glazed windows.
Here’s the kicker:
You can’t simply tear them out. Most period homes are restricted by conservation orders or are listed which protect those original windows. Then what do you do?
Secondary glazing.
Think of it as period home owners’ best secret weapon if you want to heat your home more effectively, slash your energy bills, enjoy lower noise levels and keep your original features intact. Here we explain exactly why secondary glazing is so effective on period properties – and what to look out for before you invest.
What you’ll discover:
- What Is Secondary Glazing?
- Why Period Properties Need It
- The Top Benefits Of Secondary Glazing
- What To Consider Before Installing
What Is Secondary Glazing?
Secondary glazing is a slim internal window that sits behind your existing one.
Think of it as a second layer of defence…
It doesn’t replace your existing windows, rather it complements them by sealing air space between both panes. It’s this space that works hard — keeping heat in and outside noise out.
Unlike regular double glazing or even flush casement windows, secondary glazing doesn’t involve replacing the entire window unit. Secondary glazing leaves the original frames completely intact… Which makes it ideal for Listed properties.
If you aren’t sure where to begin, hire an expert door and window company. They can look at your home and let you know if secondary glazing or flush casement windows would be best for your particular period house. Simple as that.
Why Period Properties Need It
Period homes were built differently.
Very few were built with energy efficiency in mind. If any. Prior to energy efficiency being a consideration most original timber sash and flush casements had:
- Thin, single panes of glass
- Gaps in the frame
- Aged seals (or no seals at all)
- Beautiful but draughty character
The Centre for Sustainable Energy estimates that around 10% of heat loss from an average home is lost through windows. If your Victorian/Georgian home is poorly sealed, this can be significantly higher.
Here’s the real problem:
Replacing original windows on a listed building is almost never permitted. And in conservation areas, you’ll usually need planning permission to replace them. Secondary glazing fixes both problems … without affecting the original window in any way.
The Top Benefits Of Secondary Glazing
So what do you actually get out of secondary glazing? Let’s break it down…
Massive Heat Loss Reduction
This is the big one.
The airtight gap between your original window and the second unit creates a sealed air gap which provides insulation. Research by Historic England found that secondary glazing fitted with low emissivity glass can reduce heat losses through a window by more than 60%.
That’s a serious dent in your heating bills.
And what’s even better… You don’t lose any original features of your home to achieve this level of thermal performance.
Serious Noise Reduction
Live near a busy road? A train line? A pub?
The increased air gap in secondary glazing (typically 100-200mm) makes it superb for reducing noise from outside. Much more effective than regular double glazing, as that only has a 12-16mm gap between panes.
It means a quieter bedroom. It means a more tranquil living room. It means fewer interrupted Sunday afternoons. In urban areas or homes close to transit corridors, that’s value enough right there.
Original Features Preserved
This is non-negotiable for period homeowners.
Whether your home has timber sash windows, flush casement windows, leaded panes or stained glass… Secondary glazing doesn’t touch any of them. Your house looks exactly the same from the outside.
That preserves:
- Architectural character
- Property value
- Conservation compliance
- Original craftsmanship
Lower Energy Bills
Less heat loss means less heating needed.
Secondary glazing makes your boiler easier to run during winter. It will spend less time firing up over the course of a year. That means significant savings – with current energy costs.
It’s one of the few home improvements that genuinely pays for itself over time.
Reduced Condensation & Damp
Condensation builds up on single glazed windows like nobody’s business. Cold glass surfaces hit warm air = droplets upon droplets every morning.
Secondary glazing heats the inner pane of the window… Which massively reduces condensation and all the mold problems associated with that. Fantastic news for preventing original timber frames from rotting as well.
Improved Security
Window film and added locks over your existing window creates one more layer of glass for security.
It’s not what most people buy it for, but it’s a welcome benefit. Burglars like to take the path of least resistance and having a second locked window unit makes entry more difficult.
Planning Permission? Usually Not Needed
Planning permission is not normally required for secondary glazing installations – even on listed buildings – as the system is completely reversible and contained within the building.
However, always check with your local authority first. Listed building consent can differ depending on your property/location.
What To Consider Before Installing
Before you commit, there are a few things worth thinking about:
Frame Material: Aluminium frames are sleek and elegant on period properties. Timber frames can be stained to match existing woodwork.
Glass Type: Ordinary glass is sufficient for thermal requirements. However, Acoustic laminated glass would be recommended if soundproofing is your primary concern.
Size of Air Gap: A larger gap size (100-200mm) will yield superior acoustic results. Acceptable if air gap is used solely for thermal reasons.
Opening Style: Lift-out panels, hinged openers, vertical sliders, horizontal sliders… Select how you want your window to open based on the style of your original window.
Installer: Definitely use a specialist. Secondary glazing on period properties is very much made to measure, and will require careful measuring up. A cheap installation will look awful and perform poorly.
Final Thoughts
Secondary glazing is one of the cleverest things you can invest in for a period property.
You can retain your lovely original flush casement windows or timber sash frames … But still enjoy today’s comfort, warmth and silence. It really is the best of both worlds.
To quickly recap the benefits:
- Cuts heat loss by over 60%
- Dramatically reduces external noise
- Preserves original windows and character
- Lowers your energy bills
- Reduces condensation and damp
- Adds extra security
- Usually no planning permission needed
You have a Georgian, Victorian or Edwardian house and you’ve been tolerating draughts and noise because you didn’t want to compromise the character…. Now you know there is another way.
Have a professional survey carried out. Hire someone who knows old houses. Then relax and enjoy your old house, warm, draught-free and cosy throughout the year.
