Solar Gain Analysis & Façade Optimisation
Walker Energy Analysis carries out solar gain analysis and facade optimisation, using dynamic simulation in IES Virtual Environment to quantify how much solar heat is entering a building through its glazing, and where that can be reduced without giving up the daylight the design is relying on. Glazing decisions affect cooling loads, overheating risk and daylight all at once, and they pull against each other, so the right answer is rarely as simple as adding more shading or shrinking the windows.
Balancing Solar Gain Against Daylight
Reducing solar gain and increasing daylight often pull in opposite directions. Smaller windows or a lower g-value glass cuts heat gain, but can also cut the daylight a space was designed to rely on. External shading can block unwanted summer sun while still allowing useful daylight through, but only if it’s sized and positioned correctly for the building’s actual orientation, not a generic assumption.
We model the facade as designed, quantify the solar gain entering each space across the year, and test variations, glazing ratio, glass specification, shading depth and position, orientation-specific adjustments, to find where cooling load and overheating risk can be reduced while keeping daylight performance where it needs to be. Where a design is genuinely trading one against the other, we set out that trade-off clearly, so the decision is made deliberately rather than by accident.
- Solar gain quantification through the building’s actual glazing and orientation
- Facade optioneering: testing glazing ratio, glass specification, and shading design against each other
- Shading depth and position sized to the building’s specific orientation, not a generic assumption
- Combined reporting on cooling load, overheating risk and daylight impact, so trade-offs are visible
- Recommendations that feed directly into load calculations or a TM52/TM59 overheating assessment
Where This Fits Into the Wider Design
Facade decisions made here feed directly into other work we do on a project. A reduction in solar gain lowers the cooling load a system has to be sized for, and can be the difference between a room passing or failing a TM52 or TM59 overheating assessment. If any of that work is already happening on your project, tell us early, the same model can usually support both.
Why Work With Us
We’re a specialist energy consultancy. This is the core of what we do, not a sideline. Every assessment runs through IES VE as standard, we turn changes around quickly, and results come back in a format your team can use immediately.
FAQs
Q: Does reducing solar gain always mean losing daylight?
A: Not necessarily. Well-positioned external shading can block unwanted summer sun while still allowing useful daylight through, particularly on south-facing elevations. It depends on the specific orientation and design, which is why we model it rather than apply a fixed rule.
Q: At what stage should this work start?
A: As early as possible, ideally while the facade design and glazing ratios are still under discussion, since the options available narrow quickly once the design is fixed.
Q: Can this feed into a cooling load calculation or overheating assessment?
A: Yes, reduced solar gain directly lowers cooling load and overheating risk, so this work often feeds straight into a loads calculation or a TM52/TM59 assessment already underway on the same project.
Q: What if the design needs to prioritise daylight over cooling performance, or vice versa?
A: We report the trade-off clearly rather than making the decision for you, so your design team can weigh it against the wider brief.
Get Your Facade Optimised Early
Talk to Walker Energy Analysis while glazing and shading are still open to change
Does your project need something else?