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Tag: nZEB

All New Homes Will Be Nearly Zero Energy Buildings (NZEB)

Amendments to Part L of the Building Regulations (relating to the conservation of fuel and energy in dwellings) will come into effect on 01 November 2019.

All new homes will have a typical Building Energy Rating (BER) of A2 and will be 70% more energy efficient and emit 70% less carbon dioxide than 2005 performance levels.

What is a Nearly-Zero Energy Building (NZEB)?

‘Nearly zero-energy building’ means a building that has a very high energy performance. 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.

Are there any exceptions to the new regulations?

Yes, but only if planning approval or permission has been applied for on or before 31st October 2019 and substantial work has been completed by 31st October 2020.

“Substantial work has been completed” means that the structure of the external walls of the dwelling has been erected.

 What are the key changes to TGD L Dwellings 2019?

  • MPEPC (Maximum Permitted Energy Performance Coefficient)=0.30, in order to achieve the acceptable primary energy consumption rate.
  • MPCPC (Maximum Permitted Carbon Performance Coefficient)=0.35, to demonstrate that an acceptable CO2 emission rate has been achieved.
  • Where a dwelling undergoes major renovation, the energy performance of the whole dwelling should be improved to Cost Optimal level insofar as this is technically, functionally and economically feasible.
  • Introduction of a Renewable Energy Ratio (RER) of 20%.
  • Reduction of air permeability backstop from 7m3 /hr/m2 to 5m3 /hr/m2.
  • Table 1- Reduction of wall and floor backstop U-Value from 0.21W/m2K to 0.18 W/m2K.
  • Table 1- Reduction of window backstop U-Value from 1.6 W/m2K to 1.4 W/m2K.
  • Inclusion of guidance to avoid overheating in dwellings.
  • Par 1.3.2.4 – removal of variation of U-Value with percentage glazing.
  • Introduction of calculation of Ru value for corridors in apartments.

How can compliance be achieved?

The correct specifications need to be prepared by your Architect to your specific project. Compliance is then demonstrated using the DEAP (Dwelling Energy Assessment Procedure) software.

Below is an example prepared by the Department of Housing, Planning and Local Government for a semi-detached dwelling with 126 sq.m. and with heat pump for space heating and continuous mechanical extract ventilation.

NZEB example specification
Semi-detached dwelling with 126 sq.m. and with heat pump for space heating and continuous mechanical extract ventilation

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Overview of Key Changes to TGD L – Dwellings 2019

Minimum BER Rating for New Houses Built in 2019

 

We are quickly approaching the introduction of Nearly-Zero Energy Buildings (nZEB) standard and once again we are asked to improve the energy performance of buildings.

 

What is a Nearly-Zero Energy Building (nZEB)?

‘Nearly zero-energy building’ means a building that has a very high energy performance. 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.

When will the new regulations be introduced?

Article 9(1) of Directive 2010/31/EU of the European Parliament and of the Council of 19 May 2010 on the energy performance of buildings requires that all new buildings:

– shall be nearly-zero energy buildings by 31 December 2020;

– occupied and owned by public authorities shall be nearly zero energy buildings after 31 December 2018

A full review of Part L of the Building Regulations is expected to be published very soon, this will include the nZEB standard.

What are the transitional arrangements?

This will be confirmed when the reviewed Part L of the Building Regulations is published.

The draft transitional arrangements required the standard to apply to all new dwellings commencing construction from 1st April 2019 (subject to transition).

Transitional arrangements (draft) will allow Part L-2011 Dwellings to be used when planning permission has been applied for prior to the application date of 1st April 2019 and substantial work * is completed by 31st March 2020.

*The structure of the external walls has been erected.

 

How will compliance with nZEB be demonstrated?

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

For non-domestic buildings, compliance will be demonstrated using the NEAP methodology.

 

Is nZEB standard only for new houses?

No, the new standard applies to Domestic and Non Domestic Buildings.

It also applies to existing buildings (Domestic and Non Domestic) where major renovations take place.

Major Renovation’ means the renovation of a building where more than 25% of the surface area of the building envelope undergoes renovation.

For Existing Non Domestic Buildings this will require that the building is brought up to cost optimal level, which is defined in the building regulations as:

  • Upgrade Heating System more than 15 years’ old
  • Upgrade Cooling and Ventilation Systems more than 15 years’ old
  • Upgrade Lighting more than 15 years old.

For Existing Domestic 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.

 

What are the BER requirements once nZEB standards are implemented?

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 all new builds, it is proposed that nZEB will be equivalent to a 25% improvement in energy performance on the 2011 Building Regulations.

This equates to an energy performance and carbon performance parameter that is 70% better than Ireland’s 2005 standard.

A new Nearly-Zero Energy Building (Dwelling) will typically correspond to an A2 Building Energy Rating (BER).

 

 

Will a new house be more expensive to build from 1st April 2019?

The impact on design and cost is expected to be relatively small.

The projected increase is 1.9% over current construction costs depending on the dwelling archetype and design specification applied.