New in May 2026

Heatpunk UK has been updated to enact various MCS changes to operating temperature and air change rates.

• Operating temps for post-2006 buildings have been increased in almost all rooms: https://heatloadcalculator.mcscertified.com/docs/reference-sources/design-conditions#design-room-temperaturesrooms.
  
• Air change rates now default to 0.5 for all rooms except internal: https://heatloadcalculator.mcscertified.com/docs/reference-sources/design-conditions#design-room-temperaturesinternal.
  
• Using the standard ventilation method now uses a fixed default air permeability of 12 m³/h.m² @ 50 Pa rather than using an occupancy-based estimator as before https://heatloadcalculator.mcscertified.com/docs/reference-sources/ventilation-rates#standard-airtightness-method.