Clearer Standards Needed for Basement Waterproofing
As urban landscapes in Australia and New Zealand continue to grow upwards and outwards, there’s a corresponding trend driving construction downwards, literally! Basements and substructures are increasingly part of new developments, from high-rise towers to multi-residential projects. But while these below-ground spaces are becoming more common, the industry still lacks one critical piece of guidance: a local construction code for subgrade waterproofing.
Unlike other essential building elements, basement waterproofing in Australia and New Zealand operates somewhat in a regulatory vacuum. Designers and contractors often rely on British Standard BS 8102:2022, a well-respected and technically sound framework developed for the UK. However, in practice, this standard is often misunderstood or only partially implemented.
The result? Confusion, inconsistency, and commercial risk.
A Confusing Landscape
In the absence of clear, locally relevant guidance, different stakeholders may interpret waterproofing requirements in different ways. Architects, engineers, builders, and developers may all approach the issue from different angles — some prioritising cost, others relying on tradition, and some deferring entirely to specialist consultants.
This fragmented approach often leads to:
- Inconsistent design documentation
- Late-stage decision-making, when integration with structural elements becomes difficult
- Systems with limited warranties, especially when built from multiple suppliers and installers
- A reliance on consultants to “fill in the gaps”, sometimes at considerable expense
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A Systemic Gap
Waterproofing failures in substructures are a leading cause of long-term building defects and insurance claims. Yet, in many cases, waterproofing is still considered a finishing detail, not a structural concern. This mindset has allowed cost-first decisions and “good enough” approaches to persist, even when better solutions exist.
While BS 8102:2022 has brought some much-needed structure to projects that choose to adopt it, it remains a foreign standard with limited official standing here. The industry lacks an authoritative, enforceable local standard or code to guide design, installation, and verification of subgrade waterproofing systems.
Moving Forward
There is momentum for change. More professionals are recognising the need for early waterproofing design involvement, better education, and whole-of-life performance thinking. Integrated, design-led solutions are gaining attention, especially those that link design, supply, construction monitoring, and performance warranty in a single offering.
But industry leadership is needed for systemic improvement. That may come through updated NCC inclusions, an adapted local version of BS8102, or voluntary adoption of best-practice frameworks supported by education and performance data.
Until then, waterproofing remains one of the most important yet inconsistently addressed parts of substructure construction in Australia.
Involved in basement design or construction? We’d like to here from you, whether it’s to help us learn more about the topic, or to discuss the needs of your particular project. Get in touch!
If this topic resonates for you, take a little time with our on-demand webinar “Dry Down Deep? Basement Waterproofing that Works.“
