Sam Polson breaks down the latest structural engineering saga to hit the headlines. Sam is a CPEng Structural Engineer with 20 years experience in NZ and Overseas Sam is a Chartered Member Engineering New Zealand and a Member of the Institute of Stuctural Engineers in the UK. He heads up the EDC structural team, and is a company Director. Contact Sam on 022 0680891 or sam.polson@edc.co.nz.
Christchurch City Council and the Designs of Adrian Collis
Here we go again, structural engineers in the headlines for all the wrong reasons. This time it’s the Christchurch City Council taking issue with the designs signed off by structural engineer Adrian Collis in his role at Mike Wilton Consulting Limited.
What is happening?
Adrian Collis was employed by Mike Wilton Consulting Limited which went into liquidation in July 2023. Collis was a Chartered Engineer (CPEng), but it seems that at some point his registration ceased, and Engineering New Zealand took the unusual step of advising local councils of potential issues. It seems that errors were found in Collis’ designs.
The Christchurch City Council has subsequently reviewed its files and has sent letters to the owners of about 400 homes advising them that the design work Mr Collis did on those properties may not be up to scratch, and that a note to that affect would be added to the property LIM.
In other words, a real mess dumped at the feet of unsuspecting home and building owners.
What are the design errors?
At this stage, that is very unclear. Neither Engineering New Zealand or the Council have provided any detail into what the errors are. Richard Templer of Engineering NZ has said that a sample of Collis’s work was checked during his CPEng reassessment, and that sample “contained designs that wouldn’t meet Building Code requirements for seismic engineering”. Seismic engineering concerns leave the scope for errors broad.
Mike Wilton, Collis’ old boss, has said the errors were not serious, and that “there’s about a 99.99% chance that everything will be absolutely fine”.
My take on the situation
Firstly, are the designs completed by Collis safe for continued occupation?
It seems that Mike Wilton Consulting mainly worked on houses and other residential projects up to 3 storeys (townhouses mostly), and that the errors mainly relate to seismic engineering. To me, this suggests that there is likely to be no immediate risk to structural stability. During an earthquake however, there may be some issues, but an earthquake is a rare event (even in shaky Christchurch).
I’d like to think that the Council would immediately say something to building owners and occupants if they did have serious concerns with stability or safety.
Secondly, if there are issues with the Collis designs, this presents a nightmare scenario to home and building owners. If design deficiencies are found, and these need repair or remediation, the bill for homeowners could be hefty.
Is someone liable for this mess?
Good question. I’d bet lawyers are looking at this from all the angles, and I would expect the Christchurch City Council is already getting legal advice. Could the Council be liable to homeowners for approving works found to not comply with the Building Code? That’s one for the lawyers, but if the leaky home saga is anything to go by, Council will be nervous.
As for Mike Wilton Consulting Limited, the question of liability is far murkier. The firm would almost certainly have held professional indemnity insurance at the time of the design, but whether the insurer has any continued liability given the liquidation is uncertain.
Presumably other councils will be dragged into this mess too.
What do I do if I get a letter from the council…
I recommend the first step is to talk to a CPEng Structural Engineer you trust and ask them to review the works completed by Collis. The council will provide you with the relevant files.
A quick review should be sufficient to determine if there are any immediate safety issues with your building. Your engineer should also be able to give you an initial indication on the likelihood of design errors, and the scale of remediation.
Armed with this level of initial advice, you may decide to simply crack on with the design and construction of repair works. Or you may decide that the next call is to a lawyer.
Please call me on 022 0680891 if you would like to discuss specifics with your property.
Sam Polson
CPEng Structural Engineer
