Recent natural disasters

Those of you who have been caught up in Cyclone Gabrielle and the preceding Auckland rains have had a tough time, and we hope that things come right in due course.  NZACS will respond where we can to reduce ongoing risks to your practice, and the NZIA has recently published some guidance to information to aid the road to recovery.  For our non-NZIA members, and for those of you that may be involved in remediation or salvage of damaged buildings, MBIE has some resources at https://www.building.govt.nz/managing-buildings/managing-buildings-in-an-emergency/north-island-severe-weather-events-2023/ as does CHASNZ at https://www.chasnz.org/articles/auckland-flood-remediation-how-to-keep-healthy-and-safe-while-working-on-flood-damaged-property

In some respects these recent events may lead to similar outcomes and responses as Covid:  disruption to supply chains, labour availability, and site progress.  In addition, some sites will be physically affected by flooding or landslip.  Inevitably, some of those who suffer loss will be looking around to recover uninsured losses:  you should be thinking about whether you or a project you are working on is a potential target, and if so, what you need to do about it.

Your staff losses and family disruption need to be addressed directly:  see, for example, at https://www.employers.co.nz/natural-disasters-who-pays-blog.aspx  and at the MBIE site https://www.business.govt.nz/risks-and-operations/extreme-weather-information-for-business/  
Personal or staff stress and losses may affect productivity, and to the extent this affects your projects, you should advise stakeholders at the earliest opportunity, so that mitigation can be managed.  Focussing on your personal and business well-being is likely to be more important in the immediate future than meeting (perhaps arbitrary) deadlines.

Climate change as a design input

When advising clients on site developments, in addition to compliance requirements there is a duty of care to apply your experience skills and knowledge as a professional person.

Where is it apparent that a site may be more than usually affected by climate change, higher rainfall, higher temperatures, stronger winds, flooding, landslip or off-site adverse events, these are issues to be raised with the client.  This may in turn require attendances by other consultants.

Pro-actively educating your clients on the potential risks is a better course of action than having to defend your position later.  The records you have kept of those discussions and the resulting decisions will be an important defence if a later related claim arises.

BCA processing


A member has reported that their documents submitted online are being randomly “re-arranged” by the BCA in the course of building consent processing.  This disrupts the cross-referencing between drawings/specifications/trade data with the result that consultants and trades have difficulty zeroing in on the required information.

This represents a potential risk:  if you have had a similar experience, let us know (editor.communique@gmail.com ) and we’ll think on what we can do about it.  

Members might also like to consider how their document referencing can minimise such risks.

Pre-design site information

A search for “Site” under the resources section of the NZACS website brings up several articles highlighting the necessity of getting a firm grip on site information before pencil hits paper (or mouse is engaged).  A couple of recent claims (including those in the Tales of Woe below) have spurred Alec Couchman (Claims Committee) to list some (not all-inclusive!) things to think about:

• Overhead power lines including Transpower lines
• Internal legal boundaries subdividing a site
• Boundaries which may be in doubt or ill-defined
• Flood plains and overland flow paths – is your site vulnerable to flooding?  Where is surface water coming from, where does it go, what affect will your building have on it?
• Underground services, including unmapped and unregistered public SS and SW lines, gas pipes, electrical cables, private services.
• Regional overlays on your site – Check with regional authority.  May override local council requirements.
• Set-backs due to specific regional/local conditions such as railway lines, power lines or transmission towers
• Possible redundant offal pits and/or aquifers on site, or other ground contamination.
• Cross-lease, ROW restrictions and easements
• Check site coverage, HIRTB, etc. Recent changes may have affected your site.
• Unstable land – by definition if sloping.  Do the trees on site look unusual?  Does the vegetation suggest dampness or recent re-establishment?
• Localised or site-specific vegetation/subgrade/wind/rain/drainage issues which may or may not be recorded on publicly available information.
• Protected or notable trees.
• Covenants on the land protecting views etc.
• Nearby properties or activities which may require specific design in relation to privacy or environmental issues (smells, noise, irregular activities, animals, and others not necessarily subject to regulatory control)
• Coastal land instability.  For example, Auckland Council has mapped the coastline that could be affected by coastal erosion and instability under a range of climate change (sea-level rise) scenarios and timeframes (2050, 2080, 2130).  This Area Susceptible to Coastal Instability and Erosion (ASCIE) mapping has been done at a regional-scale but is refined depending on site-specific assessments.  This will have significant implications on coastal properties.  Other regions will have similar issues.

Some of the things members can do for a successful project:

• Visit the site in person and record everything you can
• Be satisfied that the site setout is as designed (or if not, is as it should be!)
• Have a survey done showing all legal boundaries, topo levels, easements, services
• If justified, have a GRP survey done for all underground services.  Map LL and ILs
• Check local council GIS maps for all property information including any encumbrances or local council requirements which are outside the legal boundary but which might affect your site.  
• Download the local council Property File
• View all official or historical information with a critical eye, and reconcile it with your observations and common sense.  Information at a macro level may not provide the detailed information required for the specific site.
• Obtain the Certificate of Title to confirm any legal constraints, and if necessary seek legal interpretation of them.
• If appropriate, check with any architect or fellow professional who may have worked on the site previously.
• If appropriate, have a geotech assessment completed.

Tales of Woe – Site information

Here are some recent or memorable claims arising out of site information.

1. Ancient large bricked stormwater main was not where it was expected to be:  collapsed during site excavation
2. Public drain position plotted on council records.  Test drills identified “safe” locations for larger diameter piles which in due course were driven.  Two went through the known but mis-recorded drain, and on review it was discovered that the test drills self-plugged the hole they had made:  so the drain was found, but that was not known at the time.
3. Piles drilled, reinforcing placed, concrete pour underway.  The volume of concrete in one pile was significantly more than expected:  it turned out that it had been steadily blocking up a public drain seven metres below ground level.
4. Until a justifiably grumpy roofer complained, no one had flagged the issue that the roof was far too close to overhead power distribution lines.
5. Infill house on rear site built in a dip, which later proved to be an unrecorded overland flow path, later blocked by well-meaning landscaping efforts, thus creating a local lake around the house.
6. House built according to the local authority wind zone requirements, but the specific site had a much higher wind exposure.  The cladding details and structural bracing proved inadequate despite a structural engineer’s involvement.
7. Uphill site retaining wall of non-critical setout but defined height was built ahead of setting out the house.  The builder ignored the (perhaps sparse) drawing information defining the house floor levels and instead set it out from the retaining wall:  a difference of 500mm.
8. Builder issued with consent-application set of drawings to quote from.  During consenting, the Council required the building to be lifted by 500mm to avoid flooding.  Builder ignored the consent-issue drawings and built from the ones they had quoted on.  Not discovered until the pre-line inspection.
9. Mis-understood or mis-dimensioned setout drawings, discovered (a) after piles driven (b) after major project boxed and reinforced but in final pre-pour check (c) after slab poured (d) in the attempt to join up the new roof to the existing one.
10. Mis-understood height control lines:  (a) drafting line wrongly assumed as boundary (b) boundary assumed at top of a retaining wall instead of the bottom (c) position of boundary assumed within large unruly hedge which also concealed a steep drop (d) builder unilaterally decided to set the floor level higher than designed for (e) neighbour (and therefore council) placed significant importance on what reasonably seemed to be an insignificant dip in the boundary profile (f) protracted neighbours dispute over what was the “natural” level at the boundary, and at what date that should apply.

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