Expert evidence in access consulting and architectural disputes: lessons from Makita v Sprowles
We prepare detailed reports for clients, councils, certifiers and tribunals on SDA compliance, access audits and building design issues. When these reports are used in dispute resolution, they need to meet a rigorous standard of independence and transparency.
The landmark NSW Court of Appeal decision Makita (Australia) Pty Ltd v Sprowles [2001] NSWCA 305 sets the benchmark for expert evidence. Per Heydon JA at [85], an expert must:
- clearly identify the specialised field of knowledge;
- set out the facts and assumptions relied upon;
- describe the methodology used;
- explain, step by step, how specialised knowledge applies to reach the conclusions; and
- ensure opinions are based on expertise rather than lay inference or advocacy.
The original case
Ms Sprowles, a Makita employee, fell descending internal concrete stairs in June 1986, alleging the treads were slippery and lacked a non-slip finish. At trial, an expert in slipping accidents tested the treads years after the incident, concluded they lacked the required non-slip finish, and the trial judge accepted that evidence and found Makita negligent.
What a Makita-compliant report looks like
A properly structured report addressing a slip-resistance issue would typically work through:
- Qualifications — the expert's relevant training and experience in access consulting and building compliance.
- Instructions — what the expert was actually asked to assess.
- Materials and facts — site inspection details, for example surface roughness measurements taken at multiple locations, and pendulum friction tests in both dry and wet conditions.
- Methodology — the standards applied, such as AS 4663 and AS 4586 for slip resistance of pedestrian surfaces.
- Application of knowledge — for example, treads measuring a given surface roughness producing minimal mechanical interlock with shoe soles, with pendulum test results compared against the recognised safe threshold (SRV 35–44, P3 classification) under the National Construction Code, and against AS 1428.1 requirements for slip-resistant nosings with luminance contrast.
- Opinion — a clear conclusion, to the relevant standard of professional certainty, on whether the surface met the required standard.
- Limitations — a declaration of no prior involvement with the parties, agreement to the Expert Witness Code of Conduct, and confirmation the expert's sole duty is to assist the tribunal impartially.
Why this matters
Disciplined, Makita-compliant expert reports protect everyone involved. Councils, NDIS auditors, tribunals and courts can rely on a structured opinion addressing slip resistance, pedestrian surfaces and National Construction Code access requirements with confidence.