Art & Architecture + [windows]

The Glazing Conundrum for Conversion Enthusiasts
The Glazing

Another recent post on this site highlights that 'old is the new new' and in some regards, this article follows a similar theme. While a lot of Brits are head over heels in love with the whole contemporary theme, many also appreciate completely upgrading a building that is on the verge of extinction.

The idea of combining a rustic exterior with completely stylish and futuristic internal features is an approach that a lot of people are starting to follow. Unfortunately, along with that old outer shell arrive a whole host of legal issues. Heritage and conservation are two of the primary concerns and for anyone who decides to get their hands dirty in one of these projects, they'll most probably have to satisfy English Heritage as well as all of the other standard statutory requirements.

One of the most frustrating areas of such a project is the glazing. One might assume that the simple nature of windows means that they surely can't be at the centre of too many problems. However, this is seldom the case with listed properties and the general requirement is to leave the existing glazing and frames in place.

Naturally, this causes a whole host of problems. Firstly, the old style single glazing is extremely inefficient, prompting umpteen thermal difficulties that will drive your heating bills up considerably. This also relates to all of the condensation problems that can occur and due to the cold surface, it's not uncommon for the glazing to be lined with that unflattering moisture while the frames have to be regularly treated with chemicals to rid them of all of the black mould. Then, there are the other aesthetic issues and while some property owners might want to retain some 'original' features - windows rarely fall into this category.

Therefore, staying ‘original’ is certainly very difficult in relation to the windows. Fortunately, like pretty much everything in the construction industry, technology has come to the rescue. Here, we’ll take a look at some of the ways in which it’s possible to negotiate the heritage problems that surround original glazing.

Secondary Glazing

Over the years this is a solution that has become more and more popular, even if some would argue that it detracts from the quality of the interior.

The main problem that the authorities have when it comes to historic windows is their appearance from the outside. The last thing they want is for historic buildings to be donning brand new white PVC windows - it just doesn't look right, and this is something that even the most stringent building owner would struggle to disagree with.

Therefore, secondary glazing is an immediate solution. As the name indicates, this revolves another pane of glass being installed, but with the original staying in exactly the same place. This means that there is usually a significant gap between the two panes and there's no doubt that in some cases, it can look somewhat bizarre. Still, it generally satisfies English Heritage and from a thermal perspective, the extra pane of glass will work wonders. We may as well add that those dreaded condensation stains around the windows will be a thing of the past as well, as this new pane will not be coming into contact with any cold air.

Slimlite

An even more recent method has been derived from a company called Slimlite. The fact that Grand Designs have endorsed this glazing in some of their featured projects speaks volumes about its success.

In this case, the original glazing is actually removed - although the frames stay in place. Then, exceptionally thin glass, which performs as well as your standard double-glazing, is inserted into the empty frames. The end result is that the windows have the original frames, with glass that looks identical to the material that was there previously.

It's an ingenious method and can again solve all of the problems that were discussed in the early portions of this article.

Eco Ease

The final option we'll look at falls right in between the above two. In some regards, the Eco Ease concept can be described as secondary glazing as it technically results in another pane of 'glass' being installed. However, there's no significant cavity, with this 'glass' actually arriving in sticker form.

That's right, the material isn't like the standard glass that forms our windows. Instead, this is a product which can be installed via a DIY approach, or in some cases for a team of specialists to measure up and fit the glazing for you.

The fact that it is detachable will be useful for some households, while it retains impressive thermal and noise properties as well. Unsurprisingly, it arrives at a fraction of the cost - yet still manages to keep the exterior of the windows looking the same.

A Closing Thought

It’s clear to see that the problem of balancing glazing with heritage isn’t as severe as it was several years ago. At one point, the cost of fine-tuning original windows made some projects completely unviable from a financial standpoint – especially as this still prompted condensation and poor thermal performance. Therefore, the industry has progressed substantially and if you are contemplating the purchase of a historic building, one of the above solutions should at least ensure that you don’t have any troublesome heritage headaches to experience with the windows.