Non-domestic Building Regulations
Find a range of resources about Part L Building Regulation compliance for buildings other than dwellings.
Part L of the Building Regulations
The definition for Nearly Zero Energy Buildings in the Energy Performance in Buildings Directive (EPBD) is:
"a very high energy performance, as determined in accordance with Annex 1. The nearly zero or very low amount of energy required should be covered to a very significant extent by energy from renewable sources, including energy from renewable sources produced on-site or nearby".
In line with the EPBD directive, a cost-optimal analysis was carried out to define NZEB requirements. Part L of the Building Regulations defines the requirements in legislation.
NEAP is used to demonstrate compliance with Part L of the Building Regulations, including the NZEB requirements. Learn more about NEAP.
Guidance and tools
Cost optimal study
The cost-optimal study is required under the Energy Performance of Buildings Directive. This is to define the energy performance required for new buildings and major renovations. The study accounts for the capital, operational, maintenance and carbon costs of various energy efficient solutions and renewable technologies.
Further details can be found Irish Cost Optimal Report 2019.
Non-domestic NZEB requirement
For all new non-residential buildings, an equivalent to a 60% improvement in energy performance on the 2008 Building Regulations is required. This means improved energy performance for the fabric, services and lighting specification.
It also introduces a mandatory requirement for renewable sources. Renewable sources must, in general, provide 20% of the primary energy use. However, there is flexibility where the building is more energy efficient than the regulations. This typically corresponds to an A3 Building Energy Rating.
The SBEMie software version 5.5h is available to the market to demonstrate compliance with NZEB requirements.
Major renovation requirement for buildings other than dwellings
For existing buildings under EPBD, major renovation is where more than 25% of the surface area of the building envelope undergoes renovation. This will require that the building is brought up to cost-optimal levels. This is defined in the building regulations as upgrading any of the following when more than 15 years old:
- Heating system
- Cooling and ventilation system
Further details can be found on the Department of Housing, Planning and Local Government website.
2021 Part L Building Regulation Updates
The Energy Performance of Buildings Regulations 2021 (S.I. 393 of 2021) came into effect on 27th July 2021. The main provisions of these regulations are:
- Electric Vehicle (EV) Recharging Infrastructure for new buildings and buildings undergoing Major Renovation with more than 10 parking spaces.
- Building Automation and Control Systems (BACs) and EV Recharging Points (for buildings with more than 20 car parking spaces), for existing non-residential buildings by 2025.
- Self-regulating devices in new buildings, and in existing buildings when heat generators are replaced.
The Building Regulations Technical Guidance Documents L 2021 (Buildings other than Dwellings) provides guidance on the requirements for EV Recharging Infrastructure and Self-Regulating Devices in new and existing buildings undergoing renovation works.
The Energy Performance of Buildings Regulations 2021 Technical Guidance provides guidance for EVs and BACs in existing non-residential buildings by 2025.
In relation to NEAP, the provision of the infrastructure outlined above has no effect on the EPC, CPC and RER calculations. The applicable MPEPC, MPCPC and RER provisions from TGD L 2017 have not changed.
NEAP modelling guide
The NEAP modelling guide details the requirements of the NEAP software for BER calculations and for Part L compliance checking. This document provides detail on how the software models the Actual, Reference and Notional Buildings.
Annex 1 of the Energy Performance of Buildings Directive outlines requirements for determining Energy Performance of Buildings and methodologies.
In Ireland, the national calculation methodology required by the EPBD is described following the annexes of the following overarching standards which are available from NSAI (National Standards Authority of Ireland)
- I.S. EN ISO 52000-1:2017
- I.S. EN ISO 52003-1:2017
- I.S. EN ISO 52010-1:2017
- I.S. EN ISO 52016-1:2017
- I.S. EN ISO 52018-1:2017