Holistic sustainability for windows or doors


Martin McCrimmon of CMS Window Systems explains why window and door specifications need to take a holistic view on sustainability for wider social and environmental benefits.

The performance capabilities of today’s advanced window and door systems – when designed, manufactured and installed correctly – offer housing specifiers the potential to transform the energy efficiency and comfort of existing homes, as well as ensuring new properties can be built to a standard.

Given the urgent need to reduce domestic energy consumption and carbon emissions associated with our buildings, which account for 40 per cent of the UK’s total carbon emissions, understandably the focus is often on the thermal performance of windows and doors.

Great strides have been made in this respect over the past two decades in particular, with whole window U-values as low as 0.8 W/m2K available today without having to specify costly or bespoke systems or glass.

The adoption of life cycle thinking, however, in terms of a product’s design, manufacture, service life and post-use fate, enables specifiers to consider and compare the holistic sustainability of one window and door over another. Continuous innovation by companies right along the supply chain means there is always scope to improve on the sustainability credentials of a specification whenever a new project is planned, providing that it can be based on reliable information, of course.

Waste reduction and landfill

A significant amount of waste is generated when post-consumer windows and doors are removed during refurbishment projects. The carbon impact of this can significantly undermine any ‘performance in-use’ benefits of the newly installed windows and doors, which is why it is essential to manage this waste correctly.

With the right systems in place, window and door manufacturers and installers should be able to ensure no post-consumer waste goes to landfill given the high recyclability of timber, PVCu, metals, glass and other elements of windows and doors. For example, in 2018-19 CMS Window Systems diverted 100 per cent of its 2,806 tonnes of waste, including all post-use windows and doors, away from landfill – 97 per cent was recycled and 3 per cent converted from waste to energy.

Increasing recycled content

Many products used to create new windows and doors are now manufactured using recycled content.

As processes evolve, the proportion of previously used materials in PVCu profiles, glazing and metal hardware is gradually increasing in line with ‘closed loop’ thinking. For example, new double glazed units are now available containing nearly 40 per cent post-consumer glass, which eases demand for virgin raw materials.

Manufacturing and installation

How sustainable are the factories producing your new windows and doors? Standards such as ISO 14001 are a credible indicator that the right environmental practices are being adopted, but how can window and door manufacturers go the extra mile?

Fossil fuel consumption is one area. One example is heating offices and factories with biomass boilers, achieving a carbon saving of around 95 per cent versus oil. But, there is so much more that can be done to reduce the impact that a manufacturing business has on its local environment.

With the right strategy, a factory’s physical environment can actually be enhanced, rather than simply looking at how to minimise the impact of its operations. A biodiversity programme can make a big difference, with active management of local wildlife habitats on the factory site to manage flora and fauna. Even the smallest steps, such as installing bird/bee/bug boxes or regular litter clearances, are capable of making a difference, which if adopted by all manufacturers would be a powerful force for environmental improvement UK-wide.

Alongside this, with consumers shifting from diesel and petrol vehicles to electric, so to can businesses, who increasingly being able to utilise the technology as it matures and becomes more commercially viable. Ask if your suppliers are utilising electrically-powered vans to cut CO2 emissions as part of their contracts.

Socially sustainable practices

The importance of social sustainability and how businesses in the supply chain are making a positive difference to people must not be overlooked.

Strategies to ensure young people have credible career options are extremely valuable, such as apprenticeship programmes, and so is paying the Living Wage regardless of age, as well as investing in employee wellbeing. The training of mental health first aiders, for example, is one of the ways that the workplace is improving in this respect.

Economic sustainability

None of the environmental or social benefits outlined here can be delivered by a supply chain partner if they are not commercially sound, which is why the financial integrity of a supplier is crucial.

Well-managed businesses provide stable employment and re-invest profits back into the business to create more jobs and support the local economy, extending the benefits into the whole community.

Martin McCrimmon is director at CMS Window Systems.