The last thing you want to do is replace your beautiful Victorian double hung windows. Crafted with materials far superior to what 21st-century manufacturers use, like western red cedar and prized old growth hardwood, and built with a level of craftsmanship you’re simply not going to find today, this is a feature of your home you don’t want to give up on without a fight.
The problem is, whilst your Victorian sash windows have lasted beyond a century, and for some heritage homeowners, without having moved more than a millimeter or having seen more than minimal rotting, they only have a single glaze sitting between your home's interior and the external challenges of modern life.
Single glazed windows are simply not equipped to live up to current standards of energy efficiency, performance insulation, soundproofing, safety and comfort.
Whilst years ago you would have had to trade in your invaluable Victorians in order to have new double glazed windows installed, thanks to the latest advancements in window technology – including some cutting-edge innovations you won’t find from just any double glazing company – today you can keep everything you love about your Victorian windows.
And at the same time, you can enjoy the benefits of having high-performance windows that rival the best modern windows on the market.
You can retrofit your sash windows and use these modern techniques to get way more out of your Victorians than you ever realised was possible.
There's more good news.
When the work is done correctly, your windows will easily last another century, ensuring the beauty and charm, and an irreplaceable relic of a historical era will live on for the next generations.
Here are the modern capabilities available for your old Victorian double hung windows you may want to try.
Insulating Heritage Sash Windows
Ask any window company – the number one concern for owners of Victorian homes is insulation. Heritage buildings tend to have poor insulation overall, with those single glazed heritage windows being the most problematic entry point for cold drafts in the winter and the sun’s unwanted thermal UV rays in the summer.
The best solution for insulating windows is double glazing. Historically this involved replacing your single glazed windows with new double glazed windows.
But today, it’s possible to retrofit your sash windows, leaving the existing timber joinery in place – which is often considered the treasured heart of your period double hung windows. It is this handcrafted old hardwood you definitely want to keep, if possible.
Then, only the problematic single glazing, which has probably been doing a fantastic job bringing in visible light and radiating heat energy where you don't want it to go, is removed.
Instead of letting your interior heat escape in the winter and come in during the summer (no matter how many window dressings you put up to block the light, the heat’s still going to transfer through the glass itself), you can stop thermal movement in its tracks with a double glazed unit.
Double glazing works by slowing the movement of air dramatically. The small, sealed air space in between the two panes of glass within an insulating glass unit (IGU) slows thermal conductivity down to a grinding halt. Sure, some heat will move, but a huge chunk of it is not going to so you’ll notice a significant difference in both your energy usage and your home's comfort level.
Imagine watching the wind blow outside and not feeling freezing indoors. Or in the summer, having the blinds or curtains open to let in that uplifting sunshine, but your home still feels comfortably cool. That’s what your Victorian double hung windows are capable of when you use a retrofit double glazing system to insulate your windows.
Soundproofing Your Victorian Double Hung Windows
When you insulate your Victorians to stop heat loss and unwanted solar heat gain, you’re also helping to insulate against noise pollution. Double glazing heritage sash windows will help to soundproof your home, helping to dampen the sounds of modern life.
No more lying in bed listening to late night traffic or the occasional plane flying overhead. No more hearing the conversations of people walking by.
Double glazed windows will stop a lot of those sound waves and vibrations from ever permeating your window system, leaving you with a quieter, calmer, more serene living environment.
Even better, today you can opt for special acoustic grade laminated glass or superior soundproofing. Acoustic glass or laminated glass consists of two sheets of glass with an interlayer sandwiched in between that will boost acoustic performance. This new technology has totally changed what is possible in the field of soundproofing, offering an affordable, accessible option for the everyday homeowner – even one who is living in a building that’s over 100 years old!
Installing Fly Screens for Sash Windows
When you have your Victorian windows retrofitted with a double glazing system, you can also have fly screens for sash windows professionally installed. This can be difficult if you do it yourself – even a window professional who doesn’t have experience with heritage windows may find it to be a challenging job.
For example, with century-old sash windows, one or more of the sashes may be sealed shut from the generations of applied paint. Naturally, you want all that ventilation that double hung windows should offer. Professionals who regularly work specifically with heritage windows will know how to carefully remove the layers of paint to unstick the sealed sash.
Then, you can easily open both the lower and upper sash. For double hung windows, your window installers can either seal the back of the screen against the frame or use small channels on the sides to secure the fly screen frame and fine-mesh insect netting. Thermawood make their fly screen surrounds using timber to match your windows.
Dry Retrofit Double Glazing for Sash Windows
The most important characteristic of the retrofit double glazing system you use for your Victorian windows is often not addressed by window companies because it usually doesn't crop up as a problem until you've had your double glazed windows for years. You need a proper drainage system.
Unless your windows are designed for maximum drainage, your double glazing units will ultimately fail and your transformed, high-performance heritage windows are going to end up becoming an expensive, and frustrating disappointment.
This is because, with double glazing, if water has the chance to pool around your window, such as the water vapour that forms on the window and drips down to the rebate, it can damage not only the timber but also the sealing for your double glazing units. This can lead to deterioration and rotting, as well as a broken seal.
The problem is, then you may no longer have a sealed airspace within the unit, losing some of your insulation benefits. You’ll also be at risk for further moisture build-up, which creates more damage, more rotting timber, and even mould growth, which will impact your indoor air quality and create more havoc within your windows.
A little water seems like a small thing. But, in reality, that moisture is your Victorian sash windows’ Achilles heel.
Not to worry. One of the latest advancements in window technology is a special, patented drainage system, created by the double glazing experts at Thermawood. After years working with double glazing and focusing on heritage buildings in Australia – we created a model, perfected it with 3-D printing, and designed a unique dry glazing system to make Thermawood’s Retrofit Double Glazing system last.
Water has zero chance to do any damage because it quickly drains away.
So, when you turn your Victorian double hung windows into high-performance windows, without losing any of the heritage aesthetic or operation, you can feel confident they’ll last into the next era.
Combine modern window technology with classic period craftsmanship and quality, and you don’t just get beautiful Victorian windows that can live up to 21st century standards. You are looking through windows that will end up lasting, in total, centuries.
