How Solar Shading Reduces Glare, Overheating and Energy Costs

Overheating is becoming a growing concern across commercial buildings and mixed-use developments. Larger glazed areas deliver valuable natural light, but they can also increase solar heat gain, create uncomfortable glare and drive up cooling energy use. 

For architects and specifiers, effective solar shading specification is increasingly important in balancing daylight, occupant comfort and energy performance. 

Why solar shading matters

When solar radiation passes through glazing, it can become trapped within the building, raising internal temperatures and increasing demand for mechanical cooling. This affects thermal comfort, visual comfort and operational energy costs. 

External solar shading systems help address these challenges by controlling solar gain before it reaches the glass. This reduces the amount of solar heat entering the building while still allowing appropriate levels of natural light. 

Research commissioned by the BBSA has shown that external blinds can significantly reduce internal temperatures, helping to minimise reliance on air conditioning and improve energy efficiency. 

External and internal shading: understanding the difference

Internal solutions such as roller blinds can be effective for glare reduction and privacy. However, once sunlight has passed through the glazing, much of the heat has already entered the building. 

Dynamic external shading systems, especially those running parallel to the glazing such as roller and venetian blinds, can intercept solar radiation before it reaches the façade. As a result, they are more effective at reducing overheating and supporting building energy efficiency. 

Supporting compliance and performance

Solar shading is becoming an increasingly valuable tool in meeting the requirements of UK Building Regulations. 

Part O, which applies only to homes, places greater emphasis on limiting overheating risk, while Part L focuses on reducing energy consumption and carbon emissions. CIBSE guidance also highlights the importance of managing solar gain as part of a wider building performance strategy. 

By reducing cooling demand, solar shading solutions can support compliance objectives while contributing to lower energy use and improved occupant comfort. 

Key considerations for specifiers

A successful solar shading specification should be considered early in the design process. Key factors include: 

• Building orientation and exposure to direct or reflected sunlight 

• Glazing performance and solar control requirements 

• Occupancy patterns and internal heat gains 

• Solar shading strategies 

• Daylight requirements and views out 

Dynamic solar shading systems can offer additional flexibility by responding to changing conditions throughout the day, helping to maintain optimal performance. 

Delivering better buildings

As the built environment responds to rising temperatures and stricter energy targets, solar shading is becoming an essential element of sustainable design. 

When integrated early and coordinated with façade and glazing strategies, solar shading devices can reduce heat gain, improve occupant comfort, lower cooling energy demand and support long-term building performance. 

For architects and specifiers, the result is a more comfortable, energy-efficient building that performs as intended throughout its lifecycle. 

• The BBSA represents the UK’s leading solar shading specialists, providing independent guidance and access to expert manufacturers, suppliers and installers. Visit www.bbsa.org.uk to learn more and find a member.