SAP Ratings

Air Tightness Information Pack - PDF download

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The new Part L1 Conservation of Fuel and Power in new dwellings Building Regulations came into force April 2006.  To fall in line with the EU Energy Performance in Buildings Directive the new L1 document requires a major change in the way dwellings are to be assessed for compliance with energy efficiency and carbon emission standards. 

Part L1 divides into five separate criteria to be met, noting that some of the criteria are interdependent with each other:

Criterion 1 – Achieving the TER
Criterion 2 – Limits on Design Flexibility
Criterion 3 – Limiting the Effects of Solar Gains in summer
Criterion 4 – Quality of Construction and Commissioning
Criterion 5 – Providing Information (for the building operator)

Criterion one requires the proposed dwelling to be modelled and simulated using an accredited software tool to evaluate the carbon emission from a “notional dwelling”, of the same geometry and function as the actual dwelling.  An improvement factor is then applied to establish a target emission rate (TER) against which the actual design Dwelling Emission Rate (DER) must equal or better.  To fulfil the requirements of this assessment, HRS utilise Elmhurst software.  Assessments are carried out by consultants who are registered as “competent persons”.

SAP - Required Information Check Sheet (PDF Download)