If the Architect has drawn or specified something as part of the construction documentation, which can be shown not to be in compliance with the Building Regulations, they are generally held to account for this. Therefore, if the Architect makes a mistake, they are responsible.
The builder is responsible for building in accordance with the Building Regulations and with the drawings and specifications which form part of the building contract.
If the Builder ignores or alters what the architect has specified during the course of the building works, without having obtained agreement from the Architect, and the alteration or omission that the builder carries out results in a faulty design which results in a leak, or a collapse, or a fire hazard, the builder is generally responsible. Firstly, he has broken the law by not complying with the standards set out in the building regulations, and secondly he has breached the conditions of the building contract.
I would add that the architect who is carrying out periodic inspections would also be liable for bad work - if he were on notice of that bad work. So for example if it would be obvious to a competent architect that something is not right, he would have to investigate further - or be caught by negligence.
Regarding ‘wriggle room’, it must be realised that building contracts are probably unique in that variations or changes to the contract are accepted as almost inevitable
Wriggle room is determined by the test applied by the court of reasonability (e.g. a contract for €1,000,000, the architect can make changes of €1000 value without having to consult the client, but not say make changes of the order of €100,000). It can also be expressly regulated in a contract or agreement - "the architect may make changes of the order of €500 Euro per item or €2000 per month without getting client's consent before making such changes. All changes to be flagged to client after decision" etc.
The architect can decide when he deems the works to be completed so that they can be taken over by the client/employer for their intended purpose. One would imagine that the client/employer might be consulted about this. But, no, it is a matter requiring only the architect’s “opinion”.
The architect must decide, in their role as administrator, when the building has reached what is called ‘practical completion’. They reach this decision in conjunction with the contractor and the client. One can imagine clients wanting to ‘get in and unpack’ before the building has been completed to an appropriate standard, or the contractor wahting to ‘get out of there’ and claim some of his retention money (which is held back during the project and some of which becomes payable on practical completion). When the building has reached a stage where it is safely useable, and only minor works remain, it is practically complete and the architect will(and must) issue a certificate stating this. Where is the mystery?
The issue is more serious than that. The date of practical completion determines whether a building has been completed on time and who is liable (and owes money) to whom for any delays. It is an adjudicative decision as between two parties. What the article writer is suggesting here is that the client should have the power to force the builder to pay him money for delays caused or arbitrarily prolonged by the client.
There are other weird aspects to this contract: a liquidated damages clause which is more or less unenforceable, the delegation of site safety completely to the builder, and conciliation and arbitration procedures drawn up by – you’ve guessed it – the RIAI.
The LAD clause is there as a simplification of the quantification of damages under a normal court procedure. It is a simplification as it is a pre-estimate of losses based on time and is done to bring certainty to the contracting parties. The fact that it is simple means that it is cheap to determine in the event of a problem afterwards. It need not be filled in as a clause - in which case the normal rules of court apply. The reason it is "unenforceable" applies to small contracts - effectively the cost of employing professionals (construction claims analysts/delay analysts) to work through the project and determine liability is extraordinarily expensive. This is acceptable on large infrastructural projects, but not for domestic extensions. There is little that can be done about this type of problem - going to a court without the LAD clause will simply make it even more expensive.
Two things can be done - firstly go to mediation rather than to a court so actual liability need not be proved. Or else stack the contract so far in favour of the client that the contractor must account for all delays - and they can be disputed at that time (as is done in the new government forms of contract). The difficulty with this approach is that there is a large risk transfer to the contractor - a risk transfer that needs to be paid for by the client. There is also additional paperwork involved in it - again paid for by the client. For government contracts where cost certainty is more important than value for money (to avoid paper headlines screaming "overruns"), this is acceptable.
On the Health and Safety - this area is dictated by the Safety Health and Welfare at Work (Construction) Regulations 2006 - driven by the EU, not the RIAI. The building contractor takes full responsibility for the site. Actually there was an issue with the GCCC form of contract allowing the client to interfere with the control of the site by the building contractor. I haven't checked that to see if it has been amended however.
Regarding arbitration and conciliation - the only possibly objectionable part to the rules is that in the absence of agreement of the parties, an arbitrator is to be appointed by the president of the RIAI. That mirrors the situation in the Law Society form of contract, the IEI form of contract etc. - which refer back to the president of the respective organisation. The new government form of contract leaves the appointment as blank (to be filled in by the client) - but has in forms I've come across been filled in with the president of the RIAI.