Heat Loss Calculations

It all starts with a heat loss survey & calculation!

Heat loss calculations are not just required for complete new systems.
We now have an obligation to get all our heating & hot water systems running as efficiently & cleanly as possible.

By carrying out a heat loss survey on an existing system, we can identify what changes are required (if any), to get the system flow temp running at a maximum of 55 degrees (as per building regulations).

Ideally we would aim to get the flow temp down to a maximum of 45 degrees, this would make the system ‘Heat Pump Ready’.

We have 2 options depending on your circumstances:

  1. Heat Loss for existing properties (Survey required)
  2. Heat Loss for new builds & extensions (Plans required along with all U-Values)

OPTION 1 – Survey
We visit your property & carry out a survey:

  • we draw up a floor plan of your property
  • we record details of insulation, windows, doors & walls
  • we record details of existing heat emitters (radiators/ufh)
  • we record details of the current flow & return temperature from your existing boiler/heat source

Using the information gathered from the survey, we produce a full heat loss calculation for the property, detailing every room.

This information can be used to correctly size an ASHP or a gas boiler and the radiators and/or UFH running at a lower flow temp (55 degrees max) to comply with building regulations.


  • Up to 200 SqM £ 252.00
  • 200 – 400 SqM £ 420.00

CLICK HERE to see an example of a Floor Plan
CLICK HERE to see an example of a Heat Loss Report

OPTION 2 – From Plans
We request your plans & all the required U-values for the fabric of the new building
We can then produce a full heat loss calculation, and report, as above.


  • Up to 200 SqM £ 180.00
  • 200 – 400 SqM £ 300.00

Our heat loss calculations comply with CIBSE Guide A, CIBSE Domestic heating design guide, British standard BS EN 12831-1:2017 and MCS – Microgeneration Installation Standard: MIS 3005