White room with Building Energy Rating scale in bottom left corner

As of the 1st November 2019, Ireland’s new building regulations, Part L 2019, are now in effect. You may have heard some in the industry refer to these changes are Nearly Zero Energy Building, or nZEB for short. These new regulations introduce some substantial changes to the way we plan and design houses, whether building new or retrofitting an existing property. Part L 2019 is a good start in ensuring that the homes we live in use less energy, emit less greenhouse gases, and provide a comfortable and healthy indoor environment for all occupants.

Let’s take a quick look at what this means for you.

New Build & Part L 2019

New homes must be designed and constructed “to ensure that the energy performance of the building is such as to limit the amount of energy required for the operation of the building and the amount of carbon dioxide (CO2) emissions associated with this energy use”. This is achieved through:

  • The use of renewable energy sources (solar PV, wind, heat pumps)
  • Building fabric (insulation)
  • Air tightness measures
  • The use of high efficiency boilers or other technologies like heat pumps
  • Building services controls
  • Insulation of pipes, ducts and vessels
  • Mechanical ventilation systems
  • Limiting heat gains to prevent overheating
  • The overall performance of the complete building

From an insulation standpoint, there are a number of changes to the U-values that must be achieved in several building elements, including external walls and floors. For these elements specifically, the U-value requirements have dropped from 0.21W/m2K to 0.18W/m2K. In floor with underfloor heating systems, the U-values are further reduced to 0.15W/m2K. For a full list of the U-value requirements under Part L 2019, you can visit KORE’s low energy building page.

There are other elements that must be considered when planning, designing and constructing a new build, including avoiding excessive thermal bridging and avoiding interstitial condensation, the air permeability of the building’s envelope, limiting overheating, building services and heating systems.

When all is said and done, builders should be aiming to reach an A2 Building Energy Rating under the new Part L 2019 building regulations for new build projects. For the full technical requirements you can download the TGD Part L 2019 document from the Department of Housing, Planning and Local Development website.

Retrofit of Existing Dwellings

Retrofit projects and extensions are not exempt from the new Part L 2019 regulations. For example, projects that are undergoing deep renovations and refurbishment that exceed 25% of the total surface area of the building’s envelope must reach a ‘B2’ Building Energy Rating. The following are examples of measures that would trigger the regulations if the surface area being upgraded exceeds the 25% threshold:

  • External wall insulation upgrades
  • Internal wall dry lining
  • Window and door replacement
  • Replacement of the roof structure
  • Replacement of floors

Extensions which affect more than 25% of the total surface area of the building would also be considered a major renovation and would be required to meet TGD Part L 2019.

You can still upgrade shallow measures in your home without triggering major renovations. This includes:

  • Cavity wall insulation upgrades
  • Attic insulation installed between the joists at ceiling level
  • Painting or re-plastering
  • Re-slating or re-tiling a roof

The cost optimal performance level for retrofit works is 125kWh/m2/yr, or a B2 Building Energy Rating. You can view a full list of the U-value requirements on the KORE website or by visiting the Department of Housing, Planning & Local Development.

Like new build projects, retrofit works must consider the building fabric to limit heat loss and maximise heat gain, the output of space and hot water heating, limited heat loss from pipes and ductwork, ensure that all heating system (oil or gas-fired) have a minimum seasonal efficiency of 90%.

SEAI Grants & Part L 2019

Grant funding will also be affected when retrofit works trigger major renovation. For example, external wall insulation or internal wall dry lining upgrades that are more than 25% of the total surface area (heat loss area) would need to meet either of the following to be eligible for SEAI grant funding under the Better Energy Homes Scheme:

  • The building must receive a Building Energy Rating of B2 or higher or
  • The ceiling insulation must have a U-value of 0.16W/m2K and old and inefficient boilers must be replaced. In this case, the boiler must be 15 year’s old or newer and have an efficiency rating of not less than 86%

For example, if a home receives external wall insulation that totals more than 25% of the total heat-loss surface area of the building, the contractor would either have to ensure the home meets a B2 Building Energy Rating, or upgrade the attic insulation to a U-value of at least 0.16W/m2K and ensure the heating system meets the requirements listed above. Heating systems that are non-compliant would need to be upgraded.

More information for contractors can be found on SEAI’s website.

Ensure Compliance with KORE

KORE has the knowledge and experience to ensure your new build or retrofit project meets the new TGD Part L 2019 regulations. KORE’s Expanded Polystyrene insulation solutions can easily meet and exceed the required U-values at a cost-optimal level. For more information please contact our technical team today or request a quotation directly on our website. We’re here to help in any way we can!

 

published:04 Nov 2019
,