ABIC contracts: a builder's guide to Simple Works, Basic Works, and Major Works

TL;DR

ABIC contracts are used when an architect is running the job as contract administrator: the architect assesses progress claims, approves variations, and certifies practical completion rather than the builder or owner doing it themselves. SW-2018 suits mid-range residential and commercial projects (roughly $500k to $3M); MW-2018 suits large or complex work above that band; BW-2018 is a short-form commercial-only version for jobs up to around $50k. ABIC contracts are jointly published by the Australian Institute of Architects and Master Builders Australia, state-specific housing editions exist for each jurisdiction, and they are more detailed than HIA or MBA contracts. If your job has no architect administering it, ABIC is not the right suite.

What ABIC is

The Australian Building Industry Contracts (ABIC) are a suite of standard-form building contracts jointly published by the Australian Institute of Architects (AIA) and Master Builders Australia (MBA) (verified 2026-05-09). The contracts are designed for projects where a registered architect acts as contract administrator (superintendent), rather than the owner or builder self-administering.

This is the defining characteristic of ABIC and the main reason builders working on architect-led residential or commercial projects will encounter it. On jobs with no architect in the superintendent role, HIA or MBA contracts are the more common choice.

ABIC contracts are available in digital form via the AIA and MBA platforms, and as paper sets from state Master Builders associations.

The three current editions

SW-2018: Simple Works

For projects roughly between $500,000 and $3 million (verified 2026-05-09 via contractsspecialist.com.au). Housing (residential) editions are state-specific: each state’s version incorporates the relevant domestic building legislation, such as the Home Building Act 1989 (NSW) or the Domestic Building Contracts Act 1995 (VIC) (verified 2026-05-09 via AIA ABIC Digital Contracts). Commercial editions are jurisdiction-neutral.

SW-2018 covers:

Progress claims assessed and certified by the architect
Variations managed by the architect (Section J in NSW version)
Practical completion defined by the architect’s certificate
Payment obligations linked to state security of payment legislation (Section N, NSW)
Mandatory mediation for disputes before litigation (Section P, NSW)

SW-2018 does not include provisions for urgent instructions, separable parts (staged practical completion), or quality assurance systems. If those mechanisms are needed, step up to MW-2018.

MW-2018: Major Works

For large or complex projects, typically above $3 million, or where the project requires staged completion, quality assurance systems, or provisions for separate contractors and dangerous materials (verified 2026-05-09 via AIA ABIC Digital Contracts). Housing editions exist for each state.

MW-2018 adds over SW-2018:

Urgent instructions mechanism
Separable parts (staged practical completion milestones)
Quality assurance system provisions
Separate contractors clauses
Dangerous or contaminated materials provisions
Encroachments

MW-2018 is the more comprehensive contract and carries correspondingly more contract administration overhead for the architect.

BW-2018: Basic Works

A short-form contract for small commercial projects valued at up to approximately $50,000 (verified 2026-05-09 via AIA ABIC Digital Contracts). BW-2018 is commercial-only: it is not suitable for residential or domestic building work. Use it for minor fit-outs, alterations, or small additions on commercial premises where an architect is administering.

Cost Plus (CP-2014)

A separate contract for projects where the total cost cannot be confirmed at the outset. Not an updated 2018 edition; still current as CP-2014 as of 2026-05-09 (verified via AIA ABIC Digital Contracts).

State-specific housing editions

ABIC housing editions are state-specific to comply with each jurisdiction’s domestic building legislation. Master Builders associations in each state sell the state-specific versions. Examples:

NSW: ABIC SW1-2018 H NSW, ABIC MW-2018 H NSW (verified 2026-05-09 via MBA NSW store)
VIC: ABIC SW-2018 H VIC, ABIC MW-2018 H VIC (verified 2026-05-09 via MBA VIC store)

Using the wrong state’s edition on a domestic job risks non-compliance with state building legislation. Always confirm which edition your architect has specified.

How ABIC differs from HIA and MBA contracts

Feature	ABIC	HIA	MBA (BC4)
Architect required	Yes, as superintendent	No	No
Published by	AIA + MBA jointly	HIA	MBA
Best described as	Architect-administered	Builder-aligned	Builder-aligned
Complexity	Higher	Moderate	Moderate
State-specific housing versions	Yes	Yes	Yes
Dispute mechanism	Mandatory mediation	Varies by edition	Short owner response windows
Progress claims	Certified by architect	Self-submitted by builder	Self-submitted by builder

ABIC contracts are more detailed than HIA or MBA contracts and, because the architect certifies claims and assesses variations independently, they can offer a more balanced process for owners on complex or high-value residential projects (verified 2026-05-09 via Coleman Greig comparison guide). That said, HIA and MBA contracts remain more common on standard residential builds without an architect superintendent, partly because most volume builders do not engage an architect in that role.

See HIA contracts overview and MBA contracts overview for the builder-aligned alternatives.

What can go wrong

Wrong edition for state: using the commercial or wrong-state housing edition on a domestic job creates compliance gaps with state building legislation. Confirm the edition with your architect before signing.
No architect, but ABIC contract: if the contract names an architect as superintendent but none is engaged on the project, core mechanisms (progress certification, variation approval, practical completion) have no one to operate them. Disputes become harder to resolve.
Assuming ABIC favours the owner: ABIC is more balanced than purely builder-aligned contracts, but it still requires independent legal review before signing. The architect’s role as superintendent is central; their judgment drives key milestones.
Using BW-2018 on residential work: BW-2018 is commercial-only. Using it for domestic building work risks non-compliance with state home building legislation and associated owner protections.
Outdated editions: the 2008 MW and SW versions have been withdrawn from sale and use (verified 2026-05-09 via AIA Acumen practice notes). Ensure you are using 2018 editions.

References

Australian Institute of Architects, ABIC Digital Contracts (verified 2026-05-09)
AIA Acumen Practice Notes: ABIC Contracts (verified 2026-05-09)
MBA NSW: ABIC SW1-2018 H NSW store listing (verified 2026-05-09)
MBA VIC: ABIC SW-2018 H VIC store listing (verified 2026-05-09)
Coleman Greig: A guide to standard form home building contracts (verified 2026-05-09)