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L2B SBEM Calculations conducted by experienced assessors

SBEM Calculations for Conversions


Conversion SBEM calculations are required for all building conversions where there are material changes made. Without a compliant SBEM calculation you cannot legally sell or rent your property. The size of the conversion may range from a large warehouse to a small loft conversion. What ever the size, we can provide the relevant calculations you need to pass building regulations on time. 


What is a material change to a building?

  • The dwelling is used as a hotel or boarding house, where previously it was not;

  • The dwellings is used as an institution, where previously it was not;

  • The dwelling is used as a public building e.g. sports hall or community centre, where previously it was not;

  • The dwelling contains a room for residential purposes e.g. hostel or halls of residence type rooms, where previously it did not;

  • The dwelling is used as a shop, where previously it was not.

Completing an SBEM Calculation provides building control evidence that you have complied with building standards and you are meeting the required standards to produce an Energy Performance Certificate (EPC) at the end of the build. 

Conversion SBEM calculations - L2B

What do our SBEM assessors need from you?

Drawings (For proposed and existing dwelling) :

Elevation, Section Drawings 

Floor and Site Plans


Windows (Frame material, width of Gap, emissivity of glass)

Doors (Frame material, width of gap)

Heating and cooling

Ventilation system

Hot water system (Cylinder size and controls)

Calculating SBEM conversions

SBEM calculations are completed by collecting certain pieces of information from you. Once we have received this information, one of our trained SBEM assessors will begin to calculate the projected energy consumption of the proposed building. This is done by taking into account the buildings ventilation, lighting and renewable systems along with calculating the external building fabric and openings.  

When we have gathered all of the relevant information from you, our SBEM assessors will enter this into the SBEM software, which will provide the buildings dwelling emission rate (DER).  

Once the project has began, our SBEM assessors will be able to provide you with step by step advice on what may need changing to the design of the building. This will only be necessary if the SBEM calculation is failing to meet the required DER. When this has been finalised we will be able to provide you with your SBEM and EPC, enabling you to pass building regulations.


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