Design Certifiers – 3 things about certifying Part L…

by Bregs Blog admin team

l plate

Design Certifiers- 3 things you probably do not know about certifying Part L on even the smallest project such as a kitchen extension…

1. The Acceptable Construction Details (ACD) published by the Department of the Environment may not be Part L compliant (e.g. Frsi changed in February 2014, ACD not updated in 2011 etc).  See DECLG link here:

DECLG Supplementary Documents

2. A Dwelling Energy Assessment Procedure (DEAP) may not be enough to meet the Part L requirements for dwellings (e.g. surface temperature missing).  Read SEAI link here:

SEAI- How_should_thermal_bridging_be_accounted_for_in_DEAP

3. Three dimensional calculations may be required at junctions and there are only two (yes TWO) people in Ireland qualified to do this.  Read here:

NSAI- our-services: certification/agrement-certification- thermal-modellers-scheme

In the event of any problem arising on a project in relation to the conservation of fuel and energy e.g. internal mould growth or higher than expected energy bills it is likely that the building owner will seek redress against the individual who certified compliance with Part L of the Building Regulations e.g. a Design and/or Assigned Certifier.  Failure to have dealt fully with the above three points is very likely to be used to demonstrate prima facie evidence in any legal action that the certifier is liable for the defect.  There will be no liability accruing to the builder who only has to build in accordance with drawings.

Many stakeholders in the building industry have been aware of this anomaly since 2011 although no action has been taken by the Department of the Environment or the associated professional bodies to address the issue.  The situation has been exacerbated by the introduction of the Building Control (Amendment) Regulations earlier this year which has placed new and onerous liability on individual certifiers involved on building projects.

There are no provisions in S.I.9 for transition arrangements or conflicts within the technical guidance documents (TGD’s).  Quote from our previous legal post: “Certificates “…should have said ‘I am of the opinion…If you certify and the building doesn’t comply, you are liable. There is no doubt about that…” …the DECLG need to review the word “certify” as it is “an absolute“. (see post here:)

If you are not sure about any of these issues and how they impact on current projects and roles, we suggest you contact your representative body.


Other posts related to this topic:

Why the design certifier and architect need third party building fabric assessments

Opinion piece: new building regulations and materials risk analysis

Dispensations and Transition Arrangements

Practical Post 10: No retrospective compliance – BC(A)R SI.9

Practical Post 13: Duties & conflicts- BC(A)R SI.9 


NOTE: This series of posts is not meant to undermine or be in opposition to any professional advice from registered representative bodies: rather it is to offer additional technical aids to those that find themselves in the position of having to deal with SI.9 in it’s current form at present. As with all information posted on the Blog we urge all practitioners to check with their respective professional bodies before assuming any roles or duties under Building Control (Amendment) regulation (SI.9 of 2014).