New in November 2026

Updates

• We've added a new 'Temperature configuration' modal which allows you to:
  • Easily switch between 99th and 99.6th percentile outdoor design temperature in a project
  • Customise the mean annual (or ground) temperature and adjoining temperatures of a project;
  • Use temperatures included in the new CIBSE 2026 Domestic Heating Design Guide.
• The survey task has been extended:
  • The "Heat emitters section" has a new "Heat emitter photos" subsection. Upload photos here to show on the plan and the technical report.
  • A new "Room details" section has been added, which contains room notes and photos. They're also shown on the plan and the technical report.
• Clicking on a room in the floor plan will now bring up some new tabs:
  • Overview which shows the room details, including annual demand of the room and a list of emitters in the room.
  • Survey where you can upload notes and photos of the room and emitters.
  • Materials where you can view the materials used in each room.
  • Heat loss where you can view a breakdown of fabric and ventilation heat loss calculations for each room.
    
• You can now toggle on measurements in the floor plan to view room dimensions.
• A new "unheated" room type is available to use.

Fixes

• Fixed an issue where multiple dormers were not adding the same heat loss for each dormer over a room.

• Fixed dormers causing heat loss for rooms in which they are not a part of.
• Fixed ground floor u-values using the incorrect value in the CIBSE Domestic Heating Design Guide lookup table for most rooms.
• Fixed internal heat losses being factored into the displayed total external heat loss for projects with multiple floors.
• Changed the default heated adjoining temperature to 15°C and the default unheated adjoining temperature to 5°C, per updates to the National Annex . Previously they were 18°C and 10°C, respectively.
• Fixed a bug where the ventilation heat loss was unexpectedly changing when an external wall material was changed, caused by certain walls not being counted as exposed facades.

​Why have my heat losses changed since the last time I opened the project?