The Standards, Building Regulations, Definitions etc.

Requirements for Domestic Buildings

This is currently out for public consultation, refer to Department of Housing, Planning and Local Government website for proposed changes to the regulations and DEAP methodology.

For new buildings - For all new builds, its proposed that NZEB will be equivalent to a 25% improvement in energy performance on the 2011 Building Regulations. A range of examples are shown in excel versions of the DEAP software available in the public consultation.

For major renovation - For existing buildings, it is proposed that major renovation is typically activated where external wall is renovated. The cost optimal level is a primary energy performance of 125 kWh/m2/yr when calculated using DEAP or upgrade of roof insulation and heating system.

For domestic buildings, compliance will be demonstrated using the DEAP methodology. DEAP is currently being updated to account for NZEB.

What is the nZEB standard?

Definition: ‘Nearly Zero Energy Buildings’, nZEB means a building that has a very high energy performance where 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“.

What is DEAP

To prove compliance with the current building regulations, builders and designers now must use software called DEAP (Dwelling Energy Assessment Procedure) which is used to generate BER certificates. This assesses whether you have the right mix of orientation, insulation, thermal bridge free construction, airtightness and heat recovery from ventilation and other building factors to minimise overall heat loss and energy usage by the building. BER assessors also need to know about heating system efficiency, controls and renewable energy systems. A successful DEAP assessment is required for all new dwellings and a BER rating of A3 or better. EnergyCraft can provide all the technical data on all of the systems that we supply for the BER assessor, which is required for inputting the data into the DEAP software.

Deep Retrofit explained

A ‘deep retrofit’ is a complete overhaul of the fabric of your home that reduces energy use, increases warmth and comfort, and improves your Building Energy Rating (BER).

Deep Retrofit can be described as a significant upgrade to bring a home as close as possible to Nearly Zero Energy Building (nZEB) standards.

The Current Building Regulations.

All new build dwellings must comply with the Irish Building Regulations including Part L and Part F.

The Part L document sets out maximum energy usage and carbon emission levels for the dwellings. It also states that all new buildings must incorporate some form of renewable energy technology to help reduce the use of fossil fuels to heat the dwelling or to reduce the primary electricity usage. The most popular renewable energy sources used are Solar Thermal Panels for hot water, Solar PV for electricity generation and Heat Pumps for heating and hot water.

The Part F document covers ventilation in buildings and determines the correct level of ventilation to maintain good standards of indoor air quality.


As part of the SEAI Better Energy Homes programme, homeowners must carry out and publish a BER. This grant goes towards the cost of a BER assessment.

What is BER

BER stands for Building Energy Rating and a BER certificate is a label that tells you the energy efficiency of a building. Your BER is calculated through energy use for space and hot water heating, ventilation, and lighting. The number of people likely to occupy a building is also taken in consideration. This is based on the average number of occupants in buildings of a similar size. A BER certificate is only issued after a building has been surveyed by a qualified BER assessor, the building is then rated on an energy efficiency scale ranging from A to G with A being the most efficient and G, the least efficient.

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