The space heating in a dwelling is considered when calculating energy use in DEAP.


DEAP assumes that all dwellings have heating systems that can heat the entire space. Calculations take account of a main heating system and secondary heaters as described in Appendix A of the DEAP manual.


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.

Guidance and tools

Domestic fuel cost

Compare energy costs for heating and carry out a fuel cost comparison for the correct heating input in DEAP.

Solar space heating calculations

Calculate the energy contribution from solar space heating for use in DEAP. These tools calculate the contribution of solar thermal systems to domestic hot water and space heating in dwellings for individual or group heating systems.

Heating and domestic hot water systems guide

This guide from the Department of Housing, Local Government and Heritage covers conventional means to provide primary and secondary space heating and domestic hot water for dwellings. It is the supporting document referred to in Building Regulations TGD L & Energy Performance of Buildings Regulations 2019 Dwellings Part

It is a source of guidance on compliance with the requirements of the Building Regulations for space heating systems and hot water systems.