ABCB Roadshow 2024: Improving waterproofing and water shedding provisions

Let's have a look at the proposed changes to improve the waterproofing and water shedding provisions.

These aim to help reduce the incidence of building defects resulting from the ingress of water.

They'll also help resolve issues stemming from the lack of sub-surface water management in NCC 2022 and clarify the interpretation and application of multiple Performance Requirements.

Waterproofing defects can significantly impact building owners, communities and the economy.

Impacts can include costs to rectify the defects, increased maintenance costs, increased insurance premiums and reduced consumer confidence in the building and construction industry.

The proposed changes take a more holistic approach to water management by including provisions to address sub-surface water in addition to the current requirements for surface water.

These proposals were developed in consultation with a Technical Reference Group (or TRG) which included waterproofing experts and state and territory governments.

This deliberate mix of representatives ensured a balanced perspective between the interests of practitioners, governments and the community.

The proposed changes were further refined in consultation with our peak technical committee, the Building Codes Committee (or BCC), leading to enhanced cost-benefit analysis of the proposed changes.

There are a number of proposed changes for improving the waterproofing and water shedding requirements.

Firstly, we're proposing to merge Part F1 which is surface water management, rising damp and external waterproofing and Part F3 which is roof and wall cladding into a single Part F1.

We'll also be consolidating Performance Requirements F3P1 and F1P1 to F1P4 and replacing them with Performance Requirements F1P1 and F1P2.

The Objectives, Functional Statements and Performance Requirements of Part F1 will be updated to cover the management of surface water and sub-surface water.

In addition we propose to remove existing limitations relating to the application of waterproofing and weatherproofing provisions for storage-type buildings and factory buildings, so Class 7 and Class 8 buildings, so they align with the performance framework.

There'll also be a new provision for a 10-year deflection in design for structural elements in part B1.

Finally, we propose to update a number of the Deemed-to-Satisfy or DTS Provisions of Part F1 by changing some of the existing provisions and by adding new ones.

Let's have a closer look at the proposed changes to the DTS Provisions of Part F1.

The clause numbers and content of the existing DTS Provisions will be updated.

This will include bringing the DTS Provisions of Part F3 into Part F1 to provide a more logical application and support consistent interpretation.

The existing provisions in F3D2 to F3D4 will be renumbered as F1D12 to F1D15.

We'll also be including three new DTS Provisions.

Firstly, the new provision for drainage and grading to external areas, F1D4 will establish grades to the structural substrates in building elements such as concrete roofs, balconies, podiums or similar parts.

It will require concrete roofs, balconies, podiums or similar parts to have step-downs from internal areas to external areas.

These areas would also require integral hobs at their perimeters.

Secondly, the new provision for substrate materials, F1D5, will require a structural substrate in a building or part of a building, a roof, balcony, podium or similar part of a building.

Thirdly, there will be a new provision for surface finishes, F1D10 which will cover the construction of different surface finishes.

So what are the impacts?

Cost-benefit analysis of the proposed changes was conducted as part of the Consultation Regulatory Impact Statement or CRIS.

This found significant overall benefits by avoiding costly remediation work.

It's much cheaper and easier to address potential issues by building better quality buildings in the first place.

For example, the analysis showed a net benefit for apartment buildings of around $1 billion, including avoided rectification and associated costs.

For Class 3 and Class 5 to 9 buildings, the proposed changes will deliver a net benefit of around $3 billion.

On the cost side, the CRIS shows construction cost increases, particularly for balconies in apartments, which are Class 2 buildings, although the changes would be cost-neutral for basements.

We also anticipate industry retraining and education to support the changes at a cost of $7.95 million.

Improved waterproofing and water shedding provisions will help protect buildings from water damage.

This will extend the building's lifespan, maintain structural integrity and improve indoor comfort by reducing the incidence of building defects resulting from the ingress of water.

It will also reduce financial and wellbeing costs incurred by building owners, the community and the economy.

In addition, it is expected that the enhanced Performance Requirements and new DTS Provisions will give greater flexibility in design and clarity in construction.

If you'd like to provide feedback on this proposed change, visit our dedicated PCD page, abcb.gov.au/PCD.

Here you'll find links to the draft changes for Volumes 1, 2 and 3, and the Housing Provisions.

You'll also find links to support materials and technical documents to help you understand the proposed changes.

Finally, this page has a link to our consultation page where you can have your say.

The public consultation is open from 1st May to 1st July 2024.

We look forward to your input.