The notification is not related to any one specific construction product / service. Part L (Conservation of Fuel and Energy) of the Building Regulations is made up of two separate regulations and two corresponding sets of technical guidance documents, one in respect of dwellings and one in respect of buildings other than dwellings. This review of Part L focusses solely on dwellings.

The amendment of Part F (Ventilation) will apply to all buildings and will set out minimum standards to provide effective and adequate means of ventilation in buildings to ensure good indoor air quality and avoid condensation and mould growth and to limit indoor air pollution.

Draft Technical Guidance Document L - Conservation of Fuel and Energy for dwellings (2018)

Draft Technical Guidance Document F – Ventilation (2018)

The energy performance of buildings directive (recast) introduced the requirement for all new dwellings to be nearly zero energy buildings by 31 December 2020.

NZEB

The NZEB requirement will be achieved by way of a 70% improvement in energy efficiency for new dwellings (relative to 2005 base year standards). This corresponds to an improvement in Building Energy Rating from A3 to A2. A modelling and cost study was carried by an external cost economic consultant. When the uplift in cost was calculated for a range of common heating systems, renewables, and ventilation systems for typical dwellings the indicative uplift in cost was in the order of 2.5%.

Major Renovation

This Part L amendment also introduces the requirement to improve the energy performance of a dwelling to cost optimal level where an existing building undergoes a major renovation in so far as this is technically, functionally and economically feasible. A major renovation is defined as where the surface area of the works being carried out is greater than 25% of the surface area of the building envelope. The Building Energy Rating will have to be brought up to a standard equivalent to a BER rating of B3. The impact of this requirement is not expected to be significant.

Transition arrangements

In order to meet the requirements of the Energy Performance of Buildings Directive it is proposed that the NZEB requirement will apply to new dwellings commencing construction from the 1st April 2019. There is a transitional arrangement in the regulation which allows dwellings that have applied for planning permission prior to the 1st April to 2019 to be built to the previous regulations once “substantial work has been completed” by the 31st March 2020.

“Substantial work has been completed” means that the structure of the external walls has been erected. This transitional arrangement should ensure that all social housing which will be in design prior to the 1st April 2019 should not incur any additional costs or delays once the walls are erected to wall plate level by the 31st March 2020.

Ventilation

The amendment of Part F (Ventilation) will apply to all buildings and will set out minimum standards to provide effective and adequate means of ventilation in buildings to ensure good indoor air quality and avoid condensation and mould growth and to limit indoor air pollution.