EC s
The New Central GOVernment Standard
in residential Energy Analysis
Home Energy Model (HEM)
utilising dynamic simulation modelling
to get a half-hourly 365 year round energy analysis of your project.
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Welcome to DSMHEM.
*WEBSITE UNDER CONSTRUCTION*
The Future Homes Standard is soon to be the present
U-Value & Kappa Value Calculations
We provide accurate thermal transmittance (U-value) calculations for floors, walls and roofs in accordance with BS EN ISO 6946 and BS EN ISO 13370.
These feed directly into your SAP, SBEM, and Part L assessments and help you optimise your building’s insulation specification
Energy Statements
Local planning policies often set sustainability targets above Building Regulations requirements. These must be addressed through an Energy Statement.
The National Planning Policy Framework (NPPF) requires local authorities to promote sustainable development, whilst still allowing them to impose additional targets.
PSI Ψ Value Calculations
We calculate accurate linear thermal transmittance (Ψ-values) for junctions and thermal bridges in accordance with BS EN ISO 10211. Using bespoke PSI values instead of defaults improves your SAP and SBEM results, reduces heat loss, and can reveal valuable specification savings.
SBEM Commercial EPC
SBEM, or the Simplified Building Energy Model, is the standard methodology for evaluating the energy performance of non-domestic buildings across the UK. The calculation covers heating, cooling, ventilation, and lighting demands, providing a comprehensive picture of the building’s annual energy consumption and CO₂ emissions
HEM EPC
(Home Energy Model)
Set to fully replace SAP10.3 24 Months after Future Homes Standard implementation 24.03.2027.
HEM EPC's only by 2029.
*available on launch*
Simplified Overheating
Faster and cheaper than TM59, it is ideal for simple dwellings in lower-risk postcode areas and is frequently the most cost-effective compliance option for less complex homes with standard orientations.
Overglazed Extension Asessments
Planning a heavily glazed extension? Where glazing exceeds 25% of the floor area, a compliance calculation is mandatory. We carry out the necessary assessments — whether an Area Weighted U-Value or a full SAP calculation — and supply a report suitable for Building Control submission.
Measured HTC
Subject to final HEM.
Depending on the methodology used, data is collected either overnight or over a 21 day period. Following the assessment, information collected using the relevant methodology software to create a HTC value.
There are a number of different methodologies that can be used to measure HTC.
SAP EPC
(Standard Assessment Procedure)
SAP 10.2 Elmhurst accredited calculations.
SAP 10.3 24th March 2027
HEM & SAP Dual Running June 2027
HEM Only by October 2029.
TM59 Overheating
This approach is mandatory for all developments in the postcode zones identified in Appendix C It is also required in cases where the Simplified Method cannot be achieved or where the building design is more complex.
Water Consumption Calculatuons
Design calculations carried out in accordance to Approved Document G 2015 of the Building Regulations.
As Built calculations carried out using manufacturer or WRAS and or UWLA data and grey or rain water technologies.
Measured
U-Values
Subject to final HEM.
Measuring the in-situ U-value of building elements.
Recording heat flux and temperature data over 72 hours this extended monitoring period delivers greater accuracy and allows us to quantify the true in-situ U-value of walls, roofs, floors, and other building elements in accordance with ISO 9869.
Are You Ready to Accelerate Your Projects?
Most projects are designed to a brief, carefully balancing aesthetics, function, programme, and cost while navigating the many constraints of building regulations. They typically rely on standardised material specifications that achieve compliance without examining every detail.
Most assessors and firms simply certify compliance to a required threshold. Their role is limited to checking whether the submitted specification passes or fails, often without considering the project’s real-world practicalities.
At DSMHEM, we do things differently. We carry out a full review of all proposed specifications and provide clear, actionable feedback whether a better insulation specification, optimised thermal bridging details, or a revised air permeability target could maintain (or even improve) your EPC rating at a lower overall build cost.
Certified Quality Starts with Precision Assessment
Precision Assessments for Better Homes
We pride ourselves on accuracy and punctuality, working with you and for you — never against you.
Most compliance consultants simply deliver the certificate and move on. At DSMHEM, we do more.
We handle all of our services, assessments, and calculations in-house through one dedicated contact
We manage the key assessments smoothly while actively identifying cost-saving opportunities that do not compromise your EPC rating or regulatory sign-off.