Off Grid Barn Conversion achieves A rated EPC with help of Air Tightness Test

Project Details

Low Carbon Box carried out the energy assessment works for this barn conversion.

The client invested in different methods of improving insulation levels and air tightness.

The worked with Ecological Building Systems for the wall and roof insulation, together with airtight tapes and membranes.

Upon completion, the predicted EPC was due to be ‘B’ rated. We checked what air tightness test would be required to achieve an ‘A’ rating.

Due to the clients commitment, they agreed to air test the building out of curiosity and to prove the works undertaken were carried out correctly.

To achieve this there was an air permeability target of 5, and a final score of 3.6! Considering what this building used to be, this is a perfect example of putting the right work in when it counts at an early stage to ensure an excellent result and a nice warm house.

Key features

  • Off Grid (No grid supplied energy)
  • Air source heat pump
  • Solar PV
  • Excellent levels of insulation
  • Air test of 3.6 m3/hr/m2 (for conversion, not new build)



  • I would like to pass on our thanks and appreciation for your hard work, expertise and valued input to the scheme.

    James Nellist, Lindum Construction

Leave a Reply

Your email address will not be published. Required fields are marked *

clear formPost comment