DEMITONResearch / Rework statistics / No published New Zealand figure for the cost of design and documentation failures in construction
No published New Zealand figure for the cost of design and documentation failures in construction
This figure is outside your filter. Clear the filter.
No published New Zealand figure for the cost of design and documentation failures in construction: no defensible figure has been published (BRANZ (Ian Page), 2016; New Zealand; low confidence).
What it is. None: New Zealand sources give how often documents have gaps and how often design is blamed for defects, not what it costs.
Sample. Search terms: New Zealand construction design errors documentation cost percent of contract value; BRANZ consent documentation quality; design defects rework cost New Zealand; New Zealand design change cost estimators; cost of defects causes design workmanship. A frequency exists but is not a cost: BRANZ inspectors found that in 43% of 52 sets of new-house consent drawings not all details were provided and in 31% uplift fixing details were missing (SR355, section 5); and ER49 Table 2 (from BRANZ inspections) attributes 12% of defects found to poor or incomplete design against 52% to poor workmanship.
What it is not. Recorded as none on purpose: the New Zealand sources read count documents with gaps and defects by cause, and the one New Zealand cost model prices all defects together. No figure is inferred from the cause split.
Where it came from
- BRANZ (Ian Page) (2016), Consent Documentation Quality for New Housing (BRANZ Study Report SR355)Abstract; section 5 Discussion · source record
Considered and set aside
- NZ Institute of Economic Research (NZIER), for BRANZ: Prices all quality defects in new houses together (5.4% of output, modelled). Table 2 attributes 12% of defects found in inspections to poor or incomplete design, which is a share of defects, not of cost.
- BRANZ: Summary of the same model; lists poor design as one direct cause of defects and gives no cost for it.
- PricewaterhouseCoopers, for the Department of Building and Housing: Prices the leaky-building bill (NZ$11.3 billion, 2008 dollars) as a whole and does not split design from workmanship or materials; design fees appear only as a claimant transaction cost ($15,000 for a full reclad).
- Atapattu, Domingo & Sutrisna: Estimators name inadequate tender documentation and frequent design changes among the three most critical cost factors; a perception ranking with no cost magnitude in the abstract, and the full text was not available.
- Massey University (Asadi, Wilkinson, Rotimi): Rates how well the standard contract addresses rework causes, with errors in design, drawings and specifications and incomplete design among five scored adequate (Table 3, means 3.50 and 3.39 on a 5-point scale); contract coverage, not cost. The 25% of contract value rework figure it quotes comes from earlier international literature.
- New Zealand Infrastructure Commission / Te Waihanga: Notes that policy-driven added scope and design requirements raise infrastructure cost; compares unit costs and attributes no share to design or documentation.
- New Zealand Infrastructure Commission / Te Waihanga: Names an under-estimated initial cost and governance as contributors to the motorway overrun; no design-error or documentation figure.
- BRANZ (Roman Jaques): Contractors link non-standard design and inaccurate detailing (15%) to material waste; measures waste causes by respondent share, no cost.
- The Conversation (Mark Kirby, Auckland University of Technology): Opinion piece; its nearly-10% loss figure misreads the NZIER GDP effect as a defect cost and gives no design-specific number.