Assumptions, presumptions and a dwelling’s demise

//Assumptions, presumptions and a dwelling’s demise

Assumptions, presumptions and a dwelling’s demise

Associate director of Maynard Marks, Graeme Calvert, highlights the risk of making too many assumptions in a building surveyor’s line of work.

This unfortunate story for two first-home buyers in regional New Zealand regards a modest and conservative house built during 1978, about mid-way on a sloping hill site. The design drawings depict a light-weight dwelling over an engineered concrete pile foundation, a perimeter skirt of plastered fibre cement sheet and a traditional timber frame structure. The walls were clad in weatherboards called ‘Weatherisde’, a cladding with a chequered history and subsequently removed from the market. The more senior members of the Institute will remember this product.

The engineered raft and piled foundations were needed due to the site being historically filled and to allow below-ground and surface water flow-off whilst minimizing impact on the dwelling. From a visual inspection, the dwelling appeared to be built as-per the intended design. Fast-forward 19 years to 01 April (I kid you not, as no laughing matter) 1997, a plasterer applied for and was granted a building consent from the local Council to apply painted solid plaster (stucco) over the Weatherside clad walls. The application for building consent included a brief specification/scope of the proposed work, one site plan and no detail drawings.

The plasterer inspected the existing weatherboards before applying the stucco and noted in correspondence to having no knowledge of the type of land the dwelling was built on. Within two months from application, cracking appeared within the stucco.

Fast forward a further five years to 2002. A dispute between the dwelling owners of the time, the plasterer and the Council continued to August 2003 and then until dates unknown. Fast Forward a further nine years to June 2012. The stucco issue is raised again by the dwelling owners. A council site meeting took place. The Council made the following comments (summarised) in writing post the site inspection and meeting:

“The plasterer appeared happy with the proposed work and the consent was granted based on information provided… In Summary: It was common at the time of application to plaster over claddings nearing the end of their life… many houses over the country have been re-clad in a similar manner. The repair work carried out appears quite stable now… The dwelling has recently repainted… If the plaster system is well maintained Council can be satisfied on reasonable grounds it will meet the requirements of B2 Durability from the date it was installed.”

The Council building site inspection record of 11 April 1997 stated that “paper and netting had been installed over Weatherside” and “Plasterer advised Weatherside in good order”. This inspection sheet was signed as complete by the Council in June 2012.

The Council issued a code compliance certificate (CCC) for the 1997 building consent with a condition that states: “As substantial completion was achieved in November 2003; the New Zealand Building Code B2 Durability shall take effect from that date”. The CCC was granted in 2012 and issued with the knowledge of the original building design and past disputes over the cracking of the stucco. Following the issue of the CCC in 2012 the dwelling was sold and sold again.

A pre-purchase inspection took place in March 2018. The scope of the prepurchase inspection did not include the review of the council property file, this is not considered good practice. The pre purchase inspection report was divided into 10 main sections. The sections affecting this dwelling concerned weathertightness, external wall cladding and foundation & subfloor.

The weathertightness and external wall cladding sections were concluded as having a low or no level of concern from an external visual inspection. The foundation & subfloor areas as having a moderate level of concern from the inspector opening the floor access panel and viewing below into the sub-floor space. The inspector described the foundation type as a “concrete ring foundation and piles”.

During the life of the property at a time unknown, a polythene damp proof membrane (DPM) has been installed over the ground within the subfloor space.

In November 2018, Maynard Marks surveyed the dwelling following the new owner’s concerns regarding a cold, damp home and reported on the following issues:

Elevated subfloor moisture, decay to subfloor timber, borer infestation, foundation vents blocked by structures, and partially blocked by gardens and paved siteworks, stucco encasing window joinery, stucco with no clearance from horizontal surfaces, cracking to the stucco cladding, water ingress around window and door joinery. The property file was reviewed and helped inform our reporting.

Our remedial conclusion: Lift the main structure, replace the decayed floor structure, remove and replace wall cladding with consequential associated structural works. We also recommended a cost analysis be prepared and compared to a complete demolition and rebuild. This story is unresolved and continue.

We have the benefit of hindsight and this article is not to point the finger at Councils, trades people, pre-purchase inspectors, former owners or comment on responsibility. It has been written to highlight that poor decisions, some of which seem to be based on assumptions and presumptions made by various parties during the limited life of the dwelling, have contributed to its demise. The Lifespan could have been significantly longer if more accurate information was sought before assumptions and presumptions were made.

We often make assumptions, but we need to be clear that it is stated in our reporting and think about what this might mean in terms of future consequence.

Oxford English Dictionary on-line: Assumption: A thing that is accepted as true or as certain to happen, without proof – ‘they made certain assumptions about the market’
Oxford English Dictionary on-line: Presumption: The acceptance of something as true although it is not known for certain – ‘the presumption of innocence’.