± 40 sq.m. exemption from SI.9 | Kevin Tyrrell Architectural Technologist

by Bregs Blog admin team



The following opinion piece was originally submitted by Co. Wexford-based Architectural Technologist, Kevin Tyrrell, to the BRegs Blog as a comment on another post on 2nd November 2014. With his agreement, some editing and a few additions from the author we have formatted into a post here as his case was so well put.

Having read the articles and scare mongering of the last few days in relation to the situation with regards to extensions to dwelling houses, I really have a problem with how the Building Control Authority are viewing no. 1 “a dwelling” and no. 2 “an extension” in relation to S.I.9, because they are redefining them to suit themselves and causing a lot of chaos in the meantime. The following is my attempt to make sense of what each is and how they relate to Commencement and Building Control, specifically in relation to (a) extensions below 40 sq metres and (b) the issue of a cumulative total area of 40 sq metres ,being the total area of all extensions no matter when they were built, which they claim a further extension to the dwelling (which brings this total area above 40 sq m) being commenced triggers full compliance with S.I.9 by the parties involved. That is what I am attempting to sort out, so please dont take this as a legal interpretation, this is just me teasing out the process and relationships of how an extension to a dwelling house relates to S.I.9 and Commencement Notices from the most logical point of view that I can take.

S.I.9 states that its provisions ONLY apply to the following with regards to extensions : an extension to a dwelling involving a total floor area greater than 40 sq metres. Now…to me “an extension” is a singular entity that goes to make something bigger, but until it is comlpete and formally part of the whole at completion, from the view of S.I.9 it has a specific definition. It is an extension which has had Planning Permission granted and is due to be built under the regulation of S.I.9. That is all and entirely what it is. And the crux of the matter relies heavily on this and also a few other facts relating to specificity.

A commencement notice is linked to a specific Planning Application, with a specific register number and attached plans and documents. The two are intrinsically linked and the Commencement Notice refers only to the Planning Permission it is linked to. The Commencement Notice was always the mechanism by which 2 things were alerted to the County Council.

  1. That it was due its contributions and any further information listed in planning conditions must be complied with.
  2. And that the applicant was ready to build on site.

A Commencement Notice is and always has been a project specific entity, and is not and never has been linked to anything else on site.

The Planning Regulations have not changed or been altered in any way, so in actual fact a person can view 2 separate extensions under 40 sq metres as strictly 2 different entities, and as long as they satisfy the Planning and Development Act and Regulations then the amended Building Control Regulations should have nothing to say about them.

The amended Building Control Regulations are not a commentary on Planning Regulations, they are regulations governing the Building Process and how it should be undertaken.

The Planning and Development Regulations deal with the extension in relation to the whole house and its environment, the Building Control Regulations do not and never have. So it is intrinsically impossible in any way to have a link to anything else going on with the development in any way, because of one simple thing….A Commencement Notice is Project and Planning Permission Specific…and doesn’t and cant relate to anything else. It Stands Alone.

To suggest otherwise is scare mongering…and it says nowhere in the Building Control Amendment Regulations that other extensions or a cumulative size must be taken into account.

Why? Because it cant. Why? Because its Planning Permission Specific.

And I believe that because Building Control Regulations relate and comment only to a single Permission then they can have nothing to say about the cumulative size of any extensions on the house. You could have a total of 300 sq metres of extensions to the house and they may as well not exist at all as far as the Building Control Regulations are concerned.


Because prior to applying for permission the house was seen as a whole, a single dwelling. Not a dwelling with x amount of extensions and other alterations. It is and has to be viewed as a whole object. A House, a dwelling. And since I stated previously the Commencement Notice is Permission specific it relates to an extension to a dwelling…not a dwelling (as was originally granted permission under such a permission), and has been extended and altered under a different one in the past.

Specificity destroys the argument against there being a link to previous extensions which have been granted permission or are pre- 1962 or whenever Planning Regulations came into effect. As long as the dwelling house has been granted permission for its various extensions and alterations it must be seen as a specific single thing…a dwelling house, the sum of its parts.

So as S.I.9 deals with only “an” extension to “a” dwelling which is specifically linked to a single Planning Permission, it can not comment on any other previous extensions. Well….thats how I see it in a logical and hopefully a legal and regulatory sense anyway.

Only Planning Regulations exist to comment on the entire development and how a specific permission relates to the whole. If its being seen otherwise then Building Control Regulations are supplanting Planning and Development Regulations.

Other posts of interest:

Commencement notice problems | Does size matter?

Legal Alert | Commencement Notices since 1st March 2014 

3 County Councils ask Minister to Revoke SI.9

Commencement Notices – Update | 22 October 2014

Catch 22 Commencements 

Owners may need a Certifier for a Porch?

“Dangling Participles” and why all extensions may now require compliance with S.I.9: 2014

S.I.9 – Where are we now? 27 October 2014 

Press: RIAI fearful Local Authorities will start “finding something to invalidate as a method of workload control”