The crucial role of glazing in energy efficient homes

The crucial role of glazing in energy efficient homes

Featured Article
11 Apr 2019

As Featured in Glass Times Magazine - 04/19

Following the release of the Committee for Climate Change’s ‘UK Housing: Fit for the future?’ report, Phil Brown, European Regulatory Marketing Manager at Pilkington United Kingdom Limited, part of the NSG Group, discusses how glazing can provide a cost-effective way for new-builds and existing housing stock to meet stringent climate change targets.

A new report exploring UK housing stock’s preparedness to meet the challenges of climate change, from climate watchdog the Committee for Climate Change (CCC), makes for a sobering read.   

According to the research, the UK is in serious danger of missing legally mandated climate change targets – to reduce emissions by at least 80% of 1990 levels by 2050 – if swift action is not taken to adapt existing housing stock and slash the carbon footprint of new homes. Given that the report also reveals carbon emissions from homes actually increased between 2016 and 2017, we’re a long way off being fit for the future.   

Given that more than a quarter of the heat lost from homes escapes through the windows – 90% of this through the glass itself rather than other elements such as edges and frames – it is clear that glazing has an important and often overlooked role to play in making homes more energy-efficient. 

Specifying for new builds

There are currently 29 million homes in total across the UK, and the government is committed to building 1.5 million more nationwide by 2022. Given the CCC report estimates that, by 2030, emissions from homes still need to fall by 24% from 1990 levels, the energy performance of this new housing stock will be critical.

Unfortunately, as it stands, there isn’t a great deal of regulatory incentive to design energy-efficient homes. A frustrating example of this was the ‘Zero Carbon Homes’ policy in 2016, requiring all new homes built after that period to be carbon-neutral during day-to-day running, being cancelled a few months ahead of implementation.  

A report from non-profit initiative, the Energy & Climate Intelligence Unit, found that if all new homes built since 2016 were designed in accordance with this policy, occupants of new homes would be saving upwards of £200 a year on their energy bills. This is almost triple the average intended saving from the recently introduced energy price cap. 

So, how can the glazing industry do its part to make new homes more energy-efficient?

A specific way that homes can be improved in this area is triple-glazed windows, as explicitly referenced in the CCC’s report. Triple glazing units with two panes of low-emissivity (low-e) coated glass will provide significantly higher thermal insulation performance than a standard double glazing solution.

Of course, it’s important to acknowledge that triple glazing, while no doubt extremely effective, is not suited to all projects – for example, housebuilders may prefer double glazing due to its lower upfront cost. For these projects, advanced double glazing units with low-emissivity coated glass can offer similar thermal performance to (uncoated) triple glazing units. 

For instance, Pilkington energiKare™ Advantage is a double glazing unit that can deliver U-values as low as 0.9W/m2K, a figure previously only associated with triple glazing solutions. 

Retrofitting glazing into older housing stock 

Upgrading existing housing stock is another area cited in the report as requiring urgent action if we are to have any hope of addressing the challenge posed by climate change. 

But where to start?

A huge proportion of homes in the UK are older properties, with the Government’s most recent English Housing Survey revealing that more than half (56%) of the UK’s existing housing stock was built prior to 1965. Even where these properties have had their windows replaced, many will have inferior double glazing compared with today's highly energy-efficient insulating glass units; some may still have frames only suited to single glazing.

To avoid completely replacing these windows – and potentially interfering with the properties’ unique architectural appeal –ultra-thin Vacuum Insulating Glass (VIG), such as Pilkington Spacia™, may work best. This offers the thermal performance of double glazing while being just 6.5mm thick – the same width as single glazing – meaning it’s possible to upgrade a home’s insulation – and its acoustic performance – without affecting aesthetics or undertaking costly structural work. 

Making the home of the future a reality  

While we await the government's consultation on Part L in England – expected later this year, for implementation in 2020 - I sincerely hope this report may reopen some much-needed conversations on energy efficiency.  In the meantime, I feel the onus will be on the glass and glazing industry for the foreseeable future to demonstrate the benefits of energy-efficient homes. 

Innovative solutions such as energy-efficient glazing will be key to this, offering both housebuilders and the increasingly environmentally-conscious consumers they supply a clear, actionable way to make our housing stock more sustainable. The economic and environmental benefits of this would be felt for years to come.