The Dwelling Energy Assessment Procedure (DEAP) is used by BER assessors to calculate the energy performance and carbon dioxide emissions of a home's space heating, water heating, ventilation and lighting.

About DEAP software

DEAP consists of a software tool and guidance manuals. BER Assessors use DEAP to publish Building Energy Rating (BER) certificates and advisory reports for homes. DEAP is also the compliance tool specified in Part L of the Irish Building Regulations.

The DEAP software is web-based and used to calculate the annual delivered energy consumption, primary energy consumption (kWh/m2/year) and carbon dioxide emissions (kgCO2/m2/y) for standardised occupancy.

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Who can use DEAP

You do not need to be a registered BER assessor to use DEAP to carry out BER calculations. Only registered BER assessors can publish BER certificates and advisory reports through DEAP.

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Access DEAP 4

DEAP methodology documents

This section contains the core DEAP methodology documents. Please see Notice of Changes for information on updates.

DEAP Manual

The DEAP Manual describes the assessment methodology for dwellings and must be followed alongside the DEAP Survey Guide. Always use the latest version of the methodology documents.

New version applicable from 1st February 2024, see Notice of Changes

DEAP Survey Guide

The DEAP Survey Guide describes the DEAP survey methodology for dwellings. This must be followed alongside the DEAP Manual.

New version applicable from 1st February 2024, see Notice of Changes

DEAP Survey Form

This form is for use on-site to record the survey data for the BER assessment.

DEAP Guidance Document

Check this guidance document if you have questions about the DEAP Manual and Survey Guide.

We recommend you do this before contacting the BER Helpdesk.


The DEAP workbook is the BER calculator in Microsoft Excel format. You can use this workbook to view all of the calculation formulas within the DEAP software.

DEAP Methodology Update – Onsite defaults for upgraded existing dwellings

This guidance has now been integrated in DEAP Manual (version 4.2.5) and DEAP Survey Guide (version 4.1).

District Heating Methodology

Calculation of the primary energy, carbon emissions and Part L indicators for buildings connected to district heating systems require factors representative of the specific district heating system.

A calculation methodology for these factors, based on the EPB Standard I.S. EN 15316-4-5 is under development, pending the establishment and implementation of a verification mechanism for district heating data and policy decisions on the accounting for this data.

While the calculation methodology is under development, new default district heating factors have been approved by DECC and DHLGH for selected Schemes, as outlined in the document Default District Heating factors for BER calculations. These are based on conditions, including that the Schemes meet the requirements of Efficient District Heating and Cooling set out in the Energy Efficiency Directive.

Developers or operators of district heating schemes that believe their system would satisfy the definition of “Efficient district heating and cooling” in the Energy Efficiency Directive (EED), should contact SEAI for guidance on submitting their energy data. New defaults for other “Efficient district heating and cooling” schemes may be established subject to verification by SEAI. Guidance from SEAI must be sought before using district heating factors other than as specified in the document Default District Heating factors for BER calculations, or for other schemes than those included in the document.

Further tools and guidance

You can find further calculation tools and guidance documents to support the DEAP methodology in our Technical Support section.

Notice of changes

We'll keep you up to date about any upcoming changes to the DEAP software and methodology documents.

DEAP Methodology Update, 18th December 2023

A new version of the following documents will apply to BER assessments published from 1st February 2024.

The current versions of the DEAP Manual (version 4.2.4) and the DEAP Survey Guide (version 4.0.2) will continue to apply to BERs published up until 31st January 2024.

The new versions are:

The main updates include:

  • Methodology for the onsite defaults for existing dwellings (now incorporated in the Manual and Survey Guide)
  • Updates to the evidence required to use a non-default Thermal Bridging factor (Manual)
  • Inclusion of calculations for decentralised ventilation (Manual)
  • Inclusion of guidance on the calculation of u-values for knee walls (Manual)
  • The inclusion of new appendices with clarifications and photographs regarding lighting and showers (Survey Guide)
  • A new appendix with added information on CE labels and Declarations of Performance (Survey Guide)
  • Clarifications and guidance added regarding the building regulations and the requirements where the homeowner has opted out of the requirements to obtain statutory certificates of compliance (Manual and Survey Guide)

For details of the updates please consult the change logs within the documents. A comparison document with tracked changes is available on request.

Thermal bridging factor calculator Update, 18th December 2023

BER assessors can use this thermal bridging calculator to calculate a non-default thermal bridging factor for use in DEAP. This version will be required to be used from 1st February 2024.

The thermal bridging calculator was updated in line with the most recent guidance from the Department of Housing, Local Government and Heritage.

DEAP Methodology Update – Onsite defaults for upgraded existing dwellings

This applies to existing dwellings with wall, roof and window upgrades from 1st June 2023. This document supplements the existing DEAP methodology documents and will be incorporated into a DEAP manual update in Q3 of 2023.

Electricity Primary Energy and CO2 Factors for DEAP and NEAP

The electricity factors in DEAP were updated on 31st January 2023

The electricity factors in NEAP will be updated on the week starting 10th July 2023

The updated factors are:

Primary energy factor:            1.75

CO2 emission factor:              0.224kgCO2/kWh

More details on the implementation and an outline of the derivation method can be found in the following document:

Derivation of Primary Energy and CO2 Factors for Electricity in DEAP and NEAP

Electricity Primary Energy and CO2 Factors update in DEAP4

More details on the implementation and what this means to assessors in the DEAP 4 interface can be found here.

Designer Installer Sign-Off Form 5.3.4

The Designer installer sign-off form has now been updated to incorporate a new section for sign-off for Insulated Primary pipework for a DEAP assessment, there has also been amendments to the overall sign-off for Grant purposes, to view the changes within the form please see here. The Designer Installer sign-off form 5.3.4 can be found here.

HARP Heat Pump Import Release – updates to the DEAP4 user interface

The DEAP software has now been updated to prepare for the heat pump import function into DEAP from the HARP database.

To view the changes within the DEAP software following this update, please see here.

Next steps following the update to DEAP on the 10th of August.

SEAI will publish the HARP submission packs for heat pumps on the SEAI website (Q3 2022)
Manufacturers can then submit heat pump data for display on the harp database
Once processed and displayed on the harp database it will become available in DEAP for import

Cooling in dwellings

Guidance and Implementation

The DEAP methodology and software has now been updated to take account of the energy demand for cooling in dwellings.

This update will affect the calculation of a BER when there is a fixed cooling system installed in the dwelling.

All documentation has now been published (May 2022) above and in all relevant locations throughout Technical support for BER assessors sections.

Technical support

You will find a wide range of technical support for BER Assessors in this section. We recommend that you check this section before contacting the BER Helpdesk.

Technical support for BER assessors

BER Helpdesk

Contact us if you have any questions.

Call:  01 808 2029