NEF report finds that solar shading saves energy - but that’s just the start

23rd November 2016

Solar shading using blinds, shutters and awnings has a pivotal role to play in the future of the UK’s building stock but is currently poorly understood, both by construction professionals and building occupants, according to a report by the National Energy Foundation for the British Blind and Shutter Association.

The National Energy Foundation's Solar Shading Impact report finds that rising energy costs and climate change, combined with efficient, modern ‘eco’ designs, make solar shading a key issue both now and in the years ahead for architects, builders and occupants of buildings.

Poor understanding of solar shading

Our report also concludes that the importance and benefits of solar shading are currently poorly understood, both by construction professionals and building occupants. It states that if shading were considered at the design stage of a project, the benefits could be significantly enhanced by interfacing with other building services. Unfortunately, however, solar shading still tends to be approached as an optional window dressing – a soft furnishing rather than a passive solar control and daylight management tool.

The report calls on the construction industry to consider solar shading as part of a building’s overall design rather than as an optional, remedial ‘afterthought’. The report says: “It is generally recognised that considering solar shading at an early stage in design makes it easier to integrate with other parts of the building - ultimately making it more successful. The effects of solar shading go far beyond reduced glare and overheating, and impact on the whole liveability and the quality of a building’s environment.”

Energy savings through solar shading

One major benefit of solar shading is savings in energy costs, whether through heating spaces (thanks to night-time insulation) where warmth is being lost through glazing or, in warmer weather, use of air conditioning to combat overheating. Our detailed modelling of a highly glazed office unit using EnergyPlus shows that primary energy savings can be as high as 46% when external shading is used, and 13% using internal shading. This modelling also identified that other similar software was typically referring to out-of-date algorithms and methods, as opposed to using reference procedures from European or international standards.

Comfort and privacy provided through solar shading

In addition, solar shading has a role to play in maintaining and improving the comfort of those using the space. As well as the obvious impact of controlling glare, temperatures in the workplace that are either too low or too high can have a significant, detrimental effect on productivity, as can a lack of natural daylight and the quality of that light.

It was also found that solar shading brings benefits in privacy and security as well as improvements in the indoor air quality perceived by the occupant and, properly insulated, in acoustic comfort.

Furthermore, unlike so-called solar control glass with ‘permanent’ finishes, which is a purely passive product, shading solutions can dynamically react to varying external conditions – especially when controlled automatically.

Tax breaks for solar shading

Our report calls on the Government to consider tax breaks and other financial incentives for shading products, similar to those already in existence in some other European countries. 

Education of solar shading

The report also urges the shading industry to unite and step up efforts to better communicate the advantages of its products to architects, specifiers and constructors, while also educating end users better, stating: “Poorly-informed users and systems not designed to be intuitive to occupants make it harder for shading to unlock its full potential. Even automated systems can be by-passed via manual overrides.”

Solar shading retrofit

Finally, the report identifies a substantial, untapped market for retro-fitting shading systems, adding: “Eighty per cent of existing buildings will still be standing in 2050. Single and uncoated double glazing, more ‘permeable’ to solar energy, are still common in the UK’s and the EU’s existing building stock.”

Commenting on our Solar Shading Impact report, the National Energy Foundation's Energy Specialist, Federico Seguro, said:

“Against the backdrop of global warming and increasing energy prices, there's a pressing need to design buildings that don't overheat. Passive cooling techniques such as shading systems ought to be prioritised in order to reduce the need for mechanical space cooling.

"In the UK, there is an on-going failure to recognise the efficacy of solar shading as a passive solar control and daylight management tool that goes beyond simply reducing overheating, and embrace its broader benefits such as comfort and productivity. Our Solar Shading Impact report presents an evidence-based investigation into the current and potential impact of solar shading in the UK built environment, leveraging on the full benefits that are intrinsic to the optimal use of shading."

The findings of the report are also available as a British Blinds and Shutters Association infographic.