Does Your Water Infrastructure Project Suddenly Trigger DBPA and Building Commission Action?

Key Takeaways

• Discovering that your civil pipeline or sewerage works physically connect to a class 2 residential development is a red flag that your firm may owe the statutory duty of care under the Design and Building Practitioners Act 2020 (NSW) (DBPA) if the works are “construction work” under section 36 — and after Pafburn Pty Ltd v The Owners – Strata Plan No 84674 [2024] HCA 49, that duty cannot be apportioned away to parties to whom you entrusted the work.

• Broad indemnity clauses cannot shield your firm from subcontractor safety breaches, because any term transferring a WHS duty is statutorily void under the Work Health and Safety Act 2011 (NSW) (WHS Act).

• While bespoke local council contracts frequently deploy harsh notice-based time bars, the anti-contracting-out provisions of the Building and Construction Industry Security of Payment Act 1999 (NSW) (SOP Act) may preserve your right to recover progress payments.

• If connected civil works form part of residential apartment building work and are carried out in a manner that could cause significant harm, loss or property damage — including where non-compliant or unregistered designs contribute to that risk — developers (broadly defined) may face stop work orders under section 29 of the Residential Apartment Buildings (Compliance and Enforcement Powers) Act 2020 (NSW) (RAB Act), or building work rectification orders under s 33.

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You are three months into a major stormwater drainage package for a western Sydney subdivision when the principal's superintendent issues a revised drawing. It reveals that your pipeline infrastructure physically connects into the basement footprint of a new multi-unit residential apartment complex. The principal treats it as a standard variation under the civil contract, but for a water infrastructure contractor, the legal stakes have just changed entirely.

By inadvertently stepping into works that interface with a class 2 residential building without confirmed design registration and compliance pathways, your firm may now face DBPA duty-of-care exposure if the works are construction work under section 36, non-excludable statutory liabilities, and RAB Act regulatory attention through Building Commission NSW. The decisions you make in the next 48 hours will determine whether your firm mitigates that exposure or continues into avoidable statutory and program risk.

Assessing Your Immediate Exposure When Civil Works Connect to a Class 2 Development

You’ve just discovered that the stormwater drainage or sewerage network your team is installing ties directly into a new class 2 residential apartment complex. The immediate question is whether continuing work on unregistered civil designs exposes the firm to regulatory action, and what steps you must take this week to audit the contract scope.

Determining Whether to Halt Works or Issue a Formal RFI

The immediate priority is determining whether to suspend affected works or issue a formal request for information (RFI) regarding compliance with the DBPA. Making an abrupt decision to stop work based on an assumption can expose your firm to a repudiation claim, while proceeding blindly may invite regulatory prosecution. Before suspending affected work, obtain construction law advice on the contractual notice, direction and suspension provisions that apply.

Under NSW law, civil infrastructure such as stormwater drainage or sewerage networks can engage multiple regimes once it forms part of work on or related to a residential apartment building: the DBPA section 37 duty if the contractor carries out “construction work” under section 36; the DBPA regulated-design and compliance-declaration regime if the work is prescribed building work under the Act and Regulation; and RAB Act enforcement if the work is building work on a residential apartment building within section 6. Physical connection is a practical red flag, not a standalone statutory classification.

Your First 48 Hours: contractors should typically follow a strict decision sequence:

• Verify the building classification: Demand written confirmation from the principal or the principal certifier regarding the exact NCC/BCA classification of the connected structure.

• Audit the design registration: Confirm whether the civil designs you are executing have been lodged on the NSW Planning Portal as regulated designs by a registered design practitioner.

• Issue a strategic RFI: Rather than an unnotified repudiation-risk walk-off, issue a formal RFI demanding that the principal provide the necessary compliance declarations and BCA classification confirmation. The RFI should clearly state that the contractor is seeking to avoid a breach of its statutory duty of care, positioning any subsequent delay as the principal's failure to provide lawful instructions.

• Quarantine the connected works: If possible under the construction program, halt or stand down only the affected interface and redirect resources to discrete civil stages that do not interface with the class 2 structure until the compliance documentation is resolved.

Distinguishing DBPA Statutory Duties from Bespoke Contractual Indemnities

When a water infrastructure project is reclassified as connected to a class 2 structure, contractors face three conflicting liability regimes that must be clearly separated.

First, there is the statutory liability pathway imposed by legislation like the DBPA and the WHS Act. These statutes impose overriding duties that operate independently of any agreement — including non-delegable DBPA duties on persons who carry out construction work, and WHS duties on PCBUs and officers that cannot be transferred by contract.

Second, there is the contractual exposure pathway drafted into the bespoke construction contract, which typically relies on exclusion clauses and indemnities designed to push risk downstream.

Finally, there is the regulatory enforcement pathway wielded by authorities such as the NSW Building Commission, which is focused on physical site compliance and public safety rather than commercial risk allocation.

When a dispute arises, the statutory pathway will override the contractual one. Understanding this hierarchy is the foundation of any Australian construction law overview, because contractual protections cannot cure a statutory breach.

The RAB Act and Building Commission Enforcement Threat on Residential Apartment Building Work

Warning: Proceeding with construction work that interfaces with a residential apartment building (a class 2 building, or a building containing a class 2 component) using non-compliant or unregistered designs can attract rapid regulatory attention. Under the Residential Apartment Buildings (Compliance and Enforcement Powers) Act 2020 (NSW) (RAB Act), the Secretary’s functions apply to building work on such buildings that is authorised or required to be authorised by a construction certificate or complying development certificate and is incomplete or was completed within the previous 10 years (s 6).

A stop work order under section 29 is not triggered merely because an unregistered design is discovered. The statutory test is whether the Secretary is of the opinion that the building work is, or is likely to be, carried out in a manner that could result in significant harm or loss to the public or to occupiers or potential occupiers, or significant damage to property. The order is given to a “developer” — a defined term in section 4 that can include the person who arranged the work, the landowner, the principal contractor, and other prescribed persons — so civil contractors should not assume the notice will only ever land on the principal.

Separately, section 33 authorises building work rectification orders where the Secretary reasonably believes building work was or is being carried out in a way that could result in a serious defect, or that a residential apartment building has a serious defect. Because “approved plans” under the RAB Act include regulated designs under the DBPA, design non-compliance can feed that serious-defect analysis even where a stop work order is not issued. A site shutdown or rectification order can cause catastrophic program delays and significant financial consequences, and often escalates into an NSW Building Commission dispute. It remains critical to avoid commencing the regulated interface works until the principal supplies properly lodged designs and the compliance pathway is clear.

Navigating the Design and Building Practitioners Act 2020 (NSW) Statutory Overrides

Once the class 2 connection is confirmed, your firm cannot simply rely on the civil contract's limitation of liability clauses to contain the fallout. You must understand how the DBPA automatically imposes a non-delegable duty of care that fundamentally rewrites your defect exposure. At this stage, you are likely feeling trapped by an overlapping web of statutory obligations you never intended to accept on a civil project. This section clarifies exactly what this statutory liability pathway triggers, what liability you are on the hook for, and how evidence factors into your primary defence strategy.

The Automatic Extension of the Section 37 Statutory Duty of Care

Under NSW law, a person who carries out “construction work” as defined in section 36 of the DBPA owes a duty of care under section 37. Physical connection to a class 2 building is a warning sign, not a complete legal analysis on its own.

Section 36(1) defines construction work to include:

• building work (which for Part 4 includes residential building work within the meaning of the Home Building Act 1989 (NSW) (HBA));

• the preparation of regulated designs and other designs for building work;

• the manufacture or supply of a building product used for building work; and

• supervising, coordinating, project managing or otherwise having substantive control over any of the above.

The duty in section 37 is owed only where the person carries out construction work in that sense, and only in respect of economic loss caused by defects in or related to a building for which the work is done and arising from that construction work. Scope matters: a contractor who carries out a defined civil or pipeline package is not, by that fact alone, automatically liable for every defect in the broader residential development. Conversely, a project manager, director or contractor who has substantive control under section 36(1)(d) may be captured even without performing the physical work.

When your civil pipeline connects to a regulated residential building, s 37 of the DBPA can act as a statutory liability trigger.

The statute states that a person who carries out construction work has a duty to exercise reasonable care to avoid economic loss caused by defects in or related to a building for which the work is done, and arising from the construction work. This framework significantly alters standard civil defect risks. Crucially, section 39 of the Act dictates that a person who owes a duty of care under this Part is not entitled to delegate that duty. After Pafburn, that is not merely a drafting prohibition on pushing risk down the chain: within the scope of the construction work the person carries out, the duty-holder cannot discharge or limit liability simply by arranging for subcontractors or consultants to perform the work.

Relying entirely on downstream parties to wear the owners’ claim is therefore an invalid strategy. Furthermore, section 41 provides that these duties exist in addition to duties, statutory warranties or other obligations imposed under the Home Building Act 1989, other Acts or the common law, and do not limit those obligations. Section 41(3) then makes Part 4 of the DBPA subject to the Civil Liability Act 2002 (NSW) (CLA).

In short, the operative provisions work together as follows:

• DBPA Section 37 creates the duty — the obligation to exercise reasonable care to avoid economic loss from defects.

• DBPA Section 39 makes it non-delegable — a person who owes the duty is not entitled to delegate it, and cannot discharge or limit liability merely by entrusting performance to others.

• DBPA Section 40 blocks contracting out — the Part applies despite any contract to the contrary made after commencement.

• DBPA Section 41(1) and (2) make the duty concurrent — Part 4 of the DBPA is in addition to duties, statutory warranties or other obligations under the Home Building Act 1989, other Acts or the common law, and does not limit other available damages.

• DBPA section 41(3) subjects Part 4 of the DBPA to the CLA — including CLA s 5Q (liability based on non-delegable duty). After Pafburn, that DBPA–CLA interaction is central to how far proportionate liability under Part 4 of the Civil Liability Act can reduce a DBPA claim.

Why Civil Contractors Cannot Contract Out of DBPA Liability

Many civil contractors assume that standard form exclusions or "civil works only" waivers will quarantine them from DBPA capture. A limitation of liability clause is meant to cap commercial exposure if a defect emerges. But its enforceability turns on statute. Section 40 states that the Part applies despite any contracts or stipulations to the contrary made after commencement, and that no such contract operates to annul, vary or exclude a provision of the Part. Relying on a bespoke civil waiver to defeat a DBPA claim is therefore highly unlikely to succeed.

The costlier misunderstanding is a directorial one. Directors often assume that because the contracting party is a company, the section 37 duty under the DBPA stops at the corporate veil.

That assumption tends not to hold where the individual personally supervised, directed, or controlled the connected works. Under section 36(1)(d), construction work includes supervising, coordinating, project managing or otherwise having substantive control over building work, designs or building-product supply. That definition is broad enough to capture a project manager or director who was making the operative decisions at the interface.

The pattern to watch is the director who signs off the civil variation without escalating the reclassification internally, then finds themselves named individually — potentially years later — once defect proceedings begin. Actions for loss or damage arising out of defective building work are subject to the 10-year long stop in section 6.20 of the Environmental Planning and Assessment Act 1979 (NSW), alongside other applicable limitation rules, so the decision trail can remain relevant long after practical completion.

The tactical takeaway: the moment a class 2 connection surfaces, the internal decision trail matters as much as the contract. Record the reclassification, escalate it, and make the decision to proceed or halt a documented company decision rather than an individual's site call.

Proportionate Liability, Non-Delegable Duty and Cross-Claims After Pafburn

Because contractors cannot contract out of the DBPA, many firms historically looked to Part 4 of the CLA to apportion DBPA economic-loss claims among concurrent wrongdoers. That strategy is no longer reliable as a primary defence.

In Pafburn, the High Court held that the section 37 duty, read with section 39, is a non-delegable duty. By section 41(3) of the DBPA, Part 4 of the DBPA is subject to the CLA. Section 5Q of the CLA then requires the extent of liability for breach of a non-delegable duty to be determined as if the defendant were vicariously liable for the negligence of persons to whom the defendant delegated or otherwise entrusted the relevant work or task. Section 39(a) of the CLA preserves that vicarious-style liability. The result, for work entrusted downstream, is that the duty-holder cannot use Part 4 proportionate liability to reduce the owners’ claim against them by pointing to those entrusted parties. If breach and causation are proved, exposure on the claim is effectively solidary; recovery against subcontractors, consultants or other entrusted parties is pursued by cross-claim, not by shrinking the owners’ judgment through apportionment.

That does not make every civil contractor automatically liable for the entire apartment building. The scope of the section 37 duty still tracks the construction work the person carried out under section 36. A water infrastructure contractor retained only for a discrete pipeline or sewerage package is ordinarily exposed for defects arising from that work, not for unrelated building defects outside that scope. The critical risk is different: where the contractor subcontracted part of its own package, or exercised substantive control and entrusted tasks to others, Pafburn blocks easy apportionment to those parties on the DBPA claim.

Part 4 of the Civil Liability Act may still arise on particular pleadings — for example, where loss is also alleged against independent parties outside the contractor’s entrustment chain. However, Pafburn did not purport to determine every possible proportionate-liability scenario that might arise in future DBPA litigation. What it did determine is that, where the alleged concurrent wrongdoers fall within the contractor’s entrustment or delegation chain, Part 4 cannot be used to reduce the owners’ DBPA claim by apportioning liability to those parties. Accordingly, Part 4 should not be treated as the primary shield for DBPA exposure.

The practical controls are narrower and more disciplined: verify whether the works are construction work under section 36; quarantine interface works pending design compliance; preserve the instruction and variation trail; and structure contribution cross-claims early. Meticulous records of design instructions, control decisions and subcontractor performance remain essential, but they now support scope, breach, causation and cross-claim cases more than a simple proportionate-liability escape. Contribution and indemnity claims may then need to be pursued in separate court proceedings.

Overriding Unenforceable WHS Indemnities in WaterNSW and Council Contracts

Beyond defect liability, local council and government principals often insert aggressive indemnity clauses demanding you assume total responsibility for site safety. When an incident occurs, you need to know which of these contractual demands are actually legally void. If you are frustrated by heavy-handed council contracts but need the confidence to push back on unlawful risk-shifting, this section details how the statutory liability pathway overrides the contractual exposure pathway.

The Statutory Voiding of WHS Transfer Clauses

If a council contract has landed on your desk demanding that you carry total responsibility for site safety, it is worth knowing how little of that drafting actually binds you. Under the NSW WHS Act, contractual clauses attempting to transfer WHS duties are void. The intended function of a broad indemnity clause in a construction contract is to transfer the financial and legal risk of safety breaches away from the principal and onto the head contractor.

However, the enforceability of this clause depends entirely on statutory limits. Under s 272 of the WHS Act, any term of an agreement or contract that purports to exclude, limit, or modify the operation of that Act, or to transfer to another person any duty owed under it, is statutorily void. In practice, this means that despite the aggressive drafting found in many local council contracts, the principal cannot contractually outsource its own concurrent duties as a person conducting a business or undertaking (PCBU). When advising water infrastructure contractors on contract review, a New South Wales commercial lawyer will typically highlight that while these void clauses may appear intimidating on paper, SafeWork NSW will focus on who had practical control of the site, not on the invalid risk-shifting text.

The Offence of Insuring Against WHS Monetary Penalties

Warning: Even a void indemnity can become a live offence. Section 272A of the WHS Act creates a separate exposure channel for contractors dealing with indemnities and insurance. Section 272A(1) provides that a person must not, without reasonable excuse, enter into a contract of insurance or other arrangement under which the person or another person is covered for liability for a monetary penalty under the Act; and must not provide insurance or a grant of indemnity for that penalty liability, or take the benefit of such cover. Section 272A(2) places an evidential burden on the accused to establish a reasonable excuse.

A term is void to the extent it purports to cover liability for a monetary penalty under the Act. Agreeing to indemnify a principal for WHS fines, procuring a policy that attempts to do so, or taking the benefit of that arrangement may therefore constitute an offence. Contractors who sign bespoke council contracts containing penalty indemnities risk regulatory exposure if they enter into, provide, or take the benefit of the prohibited arrangement — not because paper alone is automatically criminal in every case, but because those statutory limbs are readily engaged by common drafting.

Common Traps with Bespoke Council Indemnity Clauses

Water infrastructure contractors frequently accept bespoke amendments for WaterNSW or council works containing broad indemnities that offend s 272 and s 272A. Principals lean on their bargaining power to present these as non-negotiable standard terms, leaving the contractor trying to price a risk the law forbids them from assuming.

The practical problem is timing. A procurement officer rarely has authority to redraft a standard-form indemnity, and a heavily red-lined tender is often the fastest route to being marked non-conforming.

The approach that tends to preserve the tender is to bid as conforming, then attach a short schedule of qualifications. Frame it not as a refusal but as a statement of how the clause operates at law — noting that any term transferring a WHS duty or indemnifying a penalty is read down to the extent it offends s 272 and s 272A. That reads as a clarification, not a departure.

A recurring error is the contractor who quietly prices a contingency for the void indemnity instead of qualifying it. That inflates the bid, wins nothing, and leaves an offending penalty indemnity in the executed contract, increasing the risk that a party will enter into, provide, or take the benefit of a prohibited s 272A arrangement.

It is generally more defensible to sever the penalty indemnity expressly at tender than to sign around it and argue later that it was void all along. Where the principal will not move, a side letter recording that both parties accept the statutory reading at least removes the argument that the contractor voluntarily assumed the penalty.

Securing Progress Claims Despite Broad Contractual Time Bars

If scope disputes arise due to regulatory delays or safety halts, principals often rely on draconian notice provisions to reject your variations and progress claims. However, the strict machinery of NSW security of payment legislation operates outside those contractual limits. If you are anxious about cash flow being choked off by procedural contract traps, this section details the powerful statutory mechanism available to force payment, overriding the contractual exposure pathway.

How Section 34 of the SOP Act Neutralises Harsh Notice Requirements

Section 34 of the SOP Act invalidates contractual provisions that attempt to exclude, modify or restrict a contractor's statutory rights under that Act, including the right to progress payments.

The intended function of a time bar clause is to condition the contractor's entitlement to claim variations or extensions of time upon strict adherence to tight notification windows. However, the enforceability of this clause depends on its interaction with s 34 of the Building and Construction Industry Security of Payment Act 1999 (NSW) (SOP Act). Section 34 explicitly states that the provisions of the Act have effect despite any provision to the contrary in any contract, and voids provisions that exclude, modify or restrict the Act's operation or deter a person from taking action under it.

If a principal attempts to use a harsh contractual time bar to permanently bypass a contractor's statutory right to serve a payment claim under sections 8 and 13 for construction work carried out, that attempt is vulnerable as contracting out. While a time bar may validly regulate contractual entitlements such as variations and extensions of time, it cannot extinguish the statutory progress-payment pathway.

Maintaining Valid Payment Claims Amid Scope Disputes

Example: Consider a scenario where a water infrastructure contractor halts work on a sewerage main upon discovering a DBPA class 2 connection. The delay triggers a scope dispute, and the superintendent rejects the contractor's extension of time claim because it was lodged two days outside the contract's strict time bar window. The principal subsequently refuses to assess the associated variation in the progress claim.

However, the contractor remains entitled to a progress payment under section 8 of the SOP Act and may serve a payment claim under section 13 for construction work carried out. That statutory pathway allows them to bypass a purely contractual rejection founded on a missed notice window and still pursue payment under the Act. If the principal issues a zero-dollar payment schedule relying solely on the time bar, a NSW security of payment lawyer is likely to advise proceeding to adjudication, where the adjudicator can assess the true value of the works. Section 34 prevents the contract from excluding, modifying or restricting that statutory regime, even though the time bar may still affect separate contractual variation or extension-of-time entitlements.

Running a Calderbank offer in parallel — a without-prejudice settlement offer that carries costs consequences if rejected unreasonably — may also increase the likelihood of forcing a commercial settlement before the adjudication determination is rendered.

Conclusion

When the superintendent’s revised drawing reveals that your stormwater drainage package connects into a class 2 residential basement, the rules of the game change instantly. What began as a standard civil variation becomes a high-stakes intersection of non-excludable statutory duties, RAB Act enforcement risks, and void contractual indemnities. Relying solely on the risk allocation drafted into a bespoke local council contract is often a dangerous strategy when dealing with overarching NSW safety and building legislation.

You now understand that the DBPA imposes a non-delegable duty of care on persons who carry out construction work under section 36, that the duty cannot be contracted out of, and that after Pafburn it cannot be diluted on the owners’ claim merely by pointing to subcontractors or consultants to whom the work was entrusted. You also know that broad indemnities seeking to transfer WHS duties or monetary-penalty exposure are statutorily void or prohibited, and that the anti-contracting-out provisions of the SOP Act preserve statutory payment claims even where contractual notice regimes are harsh. The legal mechanisms controlling your exposure are set by statute and appellate authority, not just by the principal’s commercial drafting.

Before committing your site teams to execute unregistered designs on connected infrastructure, your immediate next step should be auditing the specific BCA classification of the interface and issuing a formal RFI demanding compliance declarations from the principal.

Remember that the decisions made in the first 48 hours after a reclassification surfaces are the ones that determine your exposure — and several of them, from the wording of the RFI to the way a variation is signed off, carry personal liability that no contract can undo. If a revised drawing has just put your civil works in contact with a class 2 structure, have the interface reviewed before you sign the next variation. Contact Merlo Law for a construction contract review, and we will help you map your statutory exposure, protect your progress claims, and respond to the principal from a position of strength rather than assumption.

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FAQs

What should a civil contractor do first if they suspect their works connect to a class 2 building?

The first procedural mechanism is to quarantine affected interface works where the program allows and issue a formal RFI to the principal demanding verification of the building's BCA classification and design-registration status. Continuing to execute non-compliant or unregistered designs on residential apartment building work can increase regulatory exposure, including the risk of stop work orders under s 29 of the RAB Act where the statutory harm or property-damage threshold is met, and rectification orders under s 33 where serious defects are suspected. An abrupt unnotified stoppage can still create repudiation risk, so the RFI and program response should be documented with care.

Does a standard civil contract waiver protect me from DBPA liability?

No. Contractual limitation clauses do not protect contractors from the statutory duty of care. Section 40 of the DBPA provides that the Part applies despite any contracts or stipulations to the contrary made after commencement, and that no such contract operates to annul, vary or exclude a provision of the Part.

Can a local council force my firm to indemnify them for WHS breaches on site?

No, broad indemnities that attempt to transfer WHS duties are legally unenforceable. Section 272 of the Work Health and Safety Act 2011 (NSW) provides that any term of an agreement that purports to exclude, limit, or modify the operation of the Act, or to transfer any duty owed, is void.

Is it legal for a principal to require insurance that covers their WHS fines?

No. Without reasonable excuse, section 272A of the Work Health and Safety Act 2011 (NSW) prohibits entering into a contract of insurance or other arrangement covering liability for a monetary penalty under the Act, providing such insurance or indemnity, or taking the benefit of that cover. A term is void to the extent it purports to cover that penalty liability.

Can a strict contractual time bar completely defeat my right to a progress payment?

While a time bar may limit contractual claims like variations or extensions of time, it cannot extinguish your statutory right to serve a payment claim under sections 8 and 13 for construction work carried out. Section 34 of the Building and Construction Industry Security of Payment Act 1999 (NSW) provides that the Act has effect despite any contrary contract term, and voids provisions that exclude, modify or restrict the Act or deter action under it.

How can a civil contractor defend against a DBPA claim for economic loss?

After Pafburn Pty Ltd v The Owners – Strata Plan No 84674 [2024] HCA 49, proportionate liability under Part 4 of the CLA is not a reliable primary defence against persons to whom the contractor delegated or otherwise entrusted the relevant construction work. The section 37 duty is non-delegable. Through DBPA s 41(3) and CLA s 5Q, liability is treated as if the contractor were vicariously liable for those entrusted parties, so the owners’ claim is not reduced by apportionment to them. Practical defences and risk controls instead focus on whether the contractor carried out “construction work” under s 36, the scope of work from which the alleged defects arise, whether reasonable care was exercised, causation and loss, and cross-claims against downstream parties. Independent third-party contribution issues may still arise on the facts, but they should not be assumed to deliver a simple Part 4 reduction of the DBPA claim. Pafburn resolved the position in relation to delegated or entrusted parties within the duty-holder’s construction-work chain; it did not attempt to exhaustively determine every future proportionate-liability issue that may arise in DBPA litigation.

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This guide is for informational purposes only and does not constitute legal advice. For advice tailored to your specific circumstances, please contact Merlo Law

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