The Hidden Causes of Overheating in Modern Buildings

Overheating is often assumed to be caused by solar gain – but that’s rarely the full story. In most cases, the building’s own systems are silently turning up the heat.

Here’s what might be going wrong:

• Faulty BMS or controls – Issues like failed sensors, damaged wiring or software faults can affect the operation of the controls.
• Unserviced HIUs (Heat Interface Units) – Poorly performing units can drive temperature imbalances across the building.
• Pumps left on override – Without proper cycle control, systems can circulate heat constantly – even when it’s not needed.
• Inadequate insulation (lagging) – Poor-quality or missing lagging means heat escapes into risers and communal areas.
• No shut-off strategy – Some older systems run communal heating year-round, regardless of outside temperatures.

These are all fixable. But left unresolved, they lead to spiralling energy costs, frustrated residents and avoidable wear on your system.