How to choose windows and doors for an eco-friendly home

Discover how to make an environmentally-friendly choice for doors and windows, from energy efficient glazing to sustainable materials.

By Hugh Metcalf | 14 May 2020

Whether you have designs on protecting the planet or just saving money on your energy bills, making environmentally-minded choices for windows and doors goes way beyond just double glazing.


4 Kloeber Aluminium Fixed Glazing - grand designs

Image: Aluminium fixed glazing, Kloeber

Climate change is a hot topic and more than ever, we are aware of the need to reduce our impact on the environment. Choosing your doors and windows for your self‐build project is no exception. By making the right choice, you can reduce your carbon footprint, save money on bills with the benefit of creating a well‐insulated, comfortable home.

Doors and windows are a critical component in ensuring the sustainability of your project. In an average home, up to 40% of its heat loss is through doors and windows so it’s important to understand the difference between the materials in order to make an informed, responsible choice.

Energy efficiency and sustainability go hand in hand. Therefore understanding if the timber in your doors and windows is sustainably sourced or FSC certified or whether they are made of a material that can be recycled is as important as their insulation properties (measured by R‐values) and energy efficiency (measured by U‐values).

The Grand Designs magazine teamed asked the bespoke glazing specialists at Kloeber to break down the eco-credentials of the varying styles of windows and doors available. 


Kloeber timber FunkyFront timber fixed glazing on house - grand designs

Image: Timber FunkyFront windows and fixed timber glazing, Kloeber

Timber is a naturally insulating material therefore energy efficient with a U‐value of around 1.2 W/m2 for a high quality timber window. When choosing a sustainable timber, make sure it has credentials such as FSC certification that assures you the timber is sourced from a responsibly managed forest where the highest environmental standards are met.

Modern microporous paints and stains have made maintenance easy therefore increasing the life of your timber doors or windows. These paints and stains are absorbed into the wood so they don’t blister or flake and depending on the environment around the property, a high quality paint finish should only require maintenance every 8‐10 years.


Kloeber Aluminium Fixed Glazing French Doors - grand designs

Image: Aluminium fixed glazing and French doors, Kloeber

Perhaps you prefer the aesthetics of aluminium but are concerned about its eco‐credentials? Aluminium is more environmentally friendly than you might think. Often called the ‘green’ metal, it is 100% recyclable and is the most recyclable industrial material available. Recycling aluminium saves 95% of the energy required to produce it from raw material.

There is a misconception that aluminium is not energy efficient. Thermally broken aluminium (where a polyamide plastic insert separates the internal and external aluminium profiles to prevent condensation and increase insulation) is extremely energy efficient with U‐values as low as 1.2 W/mfor a window with triple glazing.

Aluminium is light but very strong so the perfect material choice for large apertures where vast expanses of glass are required. It is extremely durable and resistant to corrosion as a powder‐coated finish ensures little need for maintenance.