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Tag: Building Regulations (Page 2 of 4)

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.



Please Build Exactly as per Specifications


We always get nervous when the Contractor or the Client rings asking to change this or that. This would typically happen at construction stage and after we have spent long hours preparing construction drawings, specifications, etc. Many details are quite complex and it is not easy to change them from A to B in the hour. Furthermore, they are likely to involve extensive calculations to comply with Part L of the Building Regulations and possibly more research.

It would be easy enough to change the colour paint for a bedroom but changing a whole wall construction or even just the wall insulation is not that easy, it is time consuming and it kind of defeats the purpose of preparing pre-construction drawings.

Recently we found out on site that an existing wall was not as we had assumed in our drawings and calculations. We were prepared to review the specification and there were notes in our drawings that requested the Contractor to confirm the type of wall before proceeding with works. This was not a change requested by the client or contractor, it is just an example of what is involved when something changes. Between research, new drawings, calculations, etc there were about 10 hours extra to properly detail this variation. The image below shows one of the U-value calculations for just ONE wall. The client rarely gets to see all the work that is involved when things change on site.



In conclusion, unless there is a really good reason to change the specification, please think careful before you ask and please understand the implications not only for your Architect but also for the Assigned Certifier.

And even more important – please do not change the specifications without getting permission from the Architect/Contract Administrator!

Insulation Materials – All You Need to Know

It is easy to get confused when selecting insulation materials. There are different types of insulation, each with different forms and shapes, and a range of different properties.

Thermal properties are the primary consideration in choosing insulations.

The insulation material you choose depends on:

–  how you will use it,

–  where you will use it (there are recommended U-values for different areas of the building fabric, see below Diagram 1 from Part L of the Irish Building Regulations),

– and how much you are willing to spend.


We want to share with you two of our favourite articles/websites with helpful and unbiased information:

1 – What’s the best insulation material to use in eco renovation? by David Thorpe, and available in SuperHomes.

2 – Insulation materials 1 – Introduction by GreenSpec.


On these websites you can find answers to specific questions like:

Why should I insulate and where?

Which form of insulation material is best to use where?

How much insulation do I need?

What is the best insulation for health and climate?

Which is the best insulation for cost by volume?

What is the best insulation material for thermal performance?


You can also find detailed information about the properties of the different types of insulation:

Insulation materials 2: Plant / animal derived

Insulation materials 3: Mineral

Insulation materials 4: Oil-derived


In Ireland, Part L of the Irish Building Regulations deals with the conservation of fuel and energy. Part L is a complex and important regulation that provides guidance to ensure a better energy performance.

Diagram 1 of Part L summarises the minimum fabric insulation standards applicable in Ireland.

Part L - Irish Building Regulations - Fabric U-values


If you are still confused after reading all this information please contact us  before you make costly decisions. We can review your existing conditions, discuss options and make recommendations to improve the energy performance of your building in a sustainable and cost effective way.

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