Opinion | 40SqM BC(A)R SI.9 Extensions

by Bregs Blog admin team


The following opinion piece was submitted on 12th November by a registered professional. At time of posting the Bregs Blog is not aware of any commissioned legal opinion published or issued to members by the ACEI, SCSI or RIAI, stakeholder representative bodies. Bregs Blog notes are shown [ ]. 

An Opinion piece on 40m2 extensions

From looking at the BCMS FAO in my opinion it is quiet evident to me personally, that its presentation if the recent addition to the definition of a 40m2 extension was carried out in a rushed manner & without much care to its content.  It is looking very likely that this advice is incorrect however until this matter is comprehensively clarified, the number of Commencement Notices that stray into 40m2 cumulative territory will dramatically drop solely for one reason – Assigned Certifiers & professionals will be afraid to hand in the incorrect Commencement Notice.

It is also noted that other inaccuracies are contained within the FAO such as the possibility of self-build.  While both these sections remain, they will continue to undermine the confidence in any advice issued by BCMS.  Similarly, conflicting advice has been issued regards attic conversions & small-scale extensions by BCMS & to me personally this has now destroyed any confidence within the BCMS to issue accurate & genuine guidelines.

It beggars belief that 9 months into SI9 professionals do not know a 40m2 extension is.  It is now looking like we will run from one interpretation to another with the definition of what constitutes a 40 m extension under SI9 until the matter is – absolutely – clarified to the satisfaction of Assigned Certifiers & stakeholders.

Bar the obvious questions that have been raised, another typical example of what else needs to be clarified is if an attic conversion constitutes an extension under BCAR.

Certainly when you read TGD L 2011 Section 0.4 Dimensions, a ‘floor area’ is clearly defined:

“DIMENSIONS 0.4.1 Except where otherwise indicated linear measurements for the calculation of wall, roof andfloor areas and building volumes should be taken between the finished internal faces of the appropriate external building elements and, in the case of roofs, in the plane of the insulation. Linear measurements for the calculation of the areas of external door, window and roof light openings should be taken between internal faces of appropriate sills, lintels and reveals.”

I understand that this may refer to the calculation matters etc, relating to DEAP & Part L, however it is also clear to me personally that this section is contained within its own stand alone section.  It is my opinion that this is not specifically just geared solely to new build as it’s also incorporates the floor area of existing buildings.  Should this section be specifically be interlinked with SI9, (which it must be remembered SI9 directly applied to matters within TGDL 2011) the converted floor area of attic conversions are included as part of a 40m2 extension, because as quoted on SI9, “an extension to a dwelling involving a total floor area greater than 40 square meters”.  It might be argued that SI9 may be avoided however if the roof is already constructed as a warm roof ‘in the plane of the insulation’.  So can an attic conversion occur free of SI9 within a warm roof & not under a cold roof?  The argument is getting more bizarre every day!

This problem was flagged early in September as I personally reported the interpretation of an extension to BCMS & DECLG & questioned its interpretation.  I was disregarded by one body & ignored by another.  Now due to the horrendous definition of a 40m2 extension within SI9, this issue will run on & on & like self-build, Assigned Certifiers will soon have no confidence what so ever to the interpretation of what it truly means.

It is blatantly obvious that this matter cannot be cleared up by the addition of a couple revised lines within the COP or the revision of the FAQ within BCMS.  It has gone way beyond that now.

There is now no other solution to this fiasco other than issuing a ‘Doing Works Around the House’ guideline.  This MUST be issued on a statutory basis specifically geared to the Building Control Regulations.  This is the only way to restore confidence & allow BCMS, stakeholders, Assigned Certifiers & professionals to read off the one hymn sheet.  With this guideline, renovation works, internal alterations & extensions can be carried out in confidence that the client is not breaking the law & that correct guidelines can be followed.

Our stakeholders must request the DECLG to publish this guideline.  If stakeholders truly have their member’s best interests at heart, they will request this immediately.  If they do not, it is my personal opinion that they will loose a lot of creditability.  It is also in my opinion in the interest of the CIF to request this guideline, as if renovation works happen to stray into Commencement Notice territory & the works it is carried out independently to a supervising professional, will the building contractors PI insurance may make them the last man standing?

Finally, there is only one reason in my opinion why this fiasco has occurred.  The definition of an extension has been up in the air for months now.  Our stakeholders & governmental departments have not listened nor have they addressed it.  This has left the interpretation of an extension to be worked out by amateur opinion for months & this has lead directly to where we are now.

Other posts of interest:


Legal Alert | Commencement Notices since 1st March 2014 

Commencement notice problems | Does size matter?


Owners may need a Certifier for a Porch?

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

Catch 22 Commencements 

S.I.9 CPD | Questions for Assigned Certifier 

Design Certifier | RIAI advise separate appointment

Results | S.I. 9 Assigned Certifier Survey