• Target Emission Rate (TER): This is the maximum allowed annual CO2 emissions for a new build dwelling, set by building regulations (Approved Document L: Volume 1 or equivalent). It's calculated based on a hypothetical dwelling of the same size, built to meet minimum energy performance standards.

• Dwelling Emission Rate (DER): This is the actual annual CO2 emissions of your specific new build dwelling, calculated using an SAP assessment. It considers your planned building specifications and design choices.

Compliance Requirement:

For your new build to comply with regulations, the DER (your actual emissions) must be lower than or equal to the TER (the maximum allowed emissions).

In 2013, Dwelling Fabric Energy Efficiency (DFEE) and Target Fabric Energy Efficiency (TFEE) were introduced to promote a "Fabric First" approach in building regulations (England & Wales). This means focusing on improving the building's "fabric" (walls, windows, etc.) for energy efficiency before considering other systems.

Similar to DER/TER:

• TFEE (Target): This is the minimum acceptable energy efficiency for the building's fabric, calculated based on a hypothetical dwelling of the same size meeting basic energy standards.

• DFEE (Actual): This is the actual energy efficiency of your specific dwelling's fabric, calculated via an SAP assessment considering your planned building materials and design.

Compliance Requirement:

For compliance, the DFEE (your actual fabric efficiency) must be lower than or equal to the TFEE (the minimum required). This means your building's fabric needs to be as efficient or more efficient than the baseline standard.

Accounting for Embodied Energy (England & Wales):

Approved Document L 2021 introduced Dwelling Primary Energy Rating (DPER) and Target Primary Energy Ratings (TPER) in England and Wales.

These ratings go beyond just operational energy use (like heating and hot water) and consider the embodied energy of a dwelling. This refers to the energy used to extract, process, and transport the materials used in construction.

Understanding the Ratings:

• TPER (Target): This is the minimum acceptable level of primary energy use, considering both operational and embodied energy. It's calculated based on a hypothetical dwelling of the same size meeting basic energy standards.

• DPER (Actual): This is the actual primary energy use of your specific dwelling, calculated via an SAP assessment and considering both operational energy and the embodied energy of your chosen building materials.

Compliance Requirement:

For compliance, the DPER (your actual primary energy use) must be lower than or equal to the TPER (the minimum required). This means your chosen building materials and design should minimize the overall energy footprint of your dwelling.

Primary Energy Factor:

The Primary Energy Factor plays a role in this calculation. It's a value that reflects the energy used to produce each unit of energy used in the dwelling (e.g., electricity, gas). This factor varies depending on the fuel type.

The TER, TFEE and TPER rates are calculated based on a notional dwelling of the same size and shape as the actual proposed dwelling if it is constructed to a concurrent specification.

The concurrent specification is detailed within Table 1.1 of Section 1.0 of Approved Document L: Volume 1 and is summarised below:

It is, however, noted that these details are not prescriptive and may not be the most economically feasible option for all development. Designers and developers are therefore free to pursue other specifications provided the final DER, DFEE & DPER equal or better the TER, TFEE and TPER .

Specification improvements are usually required If a SAP calculation initially fails the minimum energy performance standards of the Building Regulations. At EPS Group, we specialise in working with our clients to devise low cost, practical options to achieving overall compliance with Approved Document L: Volume 1 (or equivalent local standard). Rest assured, we will work with you to provide options that will guarantee your SAP calculation passes.

Our fees depend on the size, complexity, and number of dwellings in your project. However, our competitive rates include:

• U-value calculations

• Building Regulation compliance advice

• FREE Predicted Energy Assessments (PEAs)

• FREE On-Construction Energy Performance Certificates (EPCs)

• Lodgement fees

For a fixed quote, email your development plans to ocdea@rd-sap.co.uk or complete our enquiry form or call anytime 0800 999 1151