Do I Need an Architect or a Building Designer?

When you're planning a significant residential project, one of the first decisions you'll face is who to engage for the design. Both registered architects and building designers can legally design homes in Australia, but their registration requirements, scope of practice, and typical fee structures differ in ways that matter at different project scales.

What Registration Actually Means

A registered architect has completed an accredited five-year degree in architecture (or equivalent), followed by a minimum two-year graduate experience program and a formal registration examination through the Architects Accreditation Council of Australia (AACA). Registration is mandatory to use the title "architect" in every Australian state and territory — it is a protected title under state legislation.

A building designer is not subject to a single national registration scheme. In Victoria and most other states, building designers working on Class 1 (residential) buildings must hold a registration under the relevant building legislation — in Victoria, this means registration as a building practitioner in the draftsperson (building design) category with the Building and Plumbing Commission (BPC), which took over from the Victorian Building Authority on 1 July 2025. Requirements vary by state, but typically involve a formal qualification and demonstrated experience rather than the broader professional examination an architect must pass.

Both are bound by professional standards and carry professional indemnity insurance, but the scope and rigour of ongoing CPD requirements, peer review mechanisms, and disciplinary processes are generally more developed in the architectural registration system.

When You Legally Need a Registered Architect

In practical terms, most Class 1 residential projects (houses, townhouses, alterations and additions) do not legally require a registered architect. However, an architect becomes either mandatory or strongly advisable in several situations:

Heritage overlays: Complex heritage projects often require the sensitivity and knowledge base that architectural registration implies. Some heritage councils and Heritage Victoria prefer or require architects for work on significant fabric.
Complex structures: Projects involving unusual structural conditions, significant cantilevers, underground structures, or work above certain heights may require professional engineer involvement — and the coordination role typically sits with the architect.
ABIC contracts: The Australian Building Industry Contracts (ABIC) suite requires a registered architect to act as contract administrator. If your project warrants a formal ABIC contract — generally where the construction value justifies independent contract administration — you need an architect.
Class 2–9 buildings: Any multi-residential (apartments), commercial, or public building requires involvement from a registered architect in most states.

What a Building Designer Can Do

For standard Class 1 residential projects — a new home, rear extension, kitchen renovation, or carport — a registered building designer can prepare permit-ready documentation, coordinate consultants, and in many cases provide a comparable quality of design service to a smaller architectural practice. Many excellent residential building designers specialise in particular typologies (knockdown-rebuild, heritage restorations, dual occupancy) and develop deep expertise in those areas.

The Cost Difference

Fees for architectural services on a full residential project typically range from 8–15% of the construction cost for a complete service from brief through to construction administration. On a $600,000 construction project, this equates to $48,000–$90,000 in professional fees. Building designers typically charge 3–6% for an equivalent scope, though many practices quote fixed or stage-based fees rather than percentages.

The cost gap is real, but so is the scope difference. An architect's fee at the higher end of the range typically includes project management, consultant coordination, on-site construction administration, and contract administration — services that, if not provided by your designer, you will either provide yourself or pay others to provide.

Choosing the Right Professional

Choose a registered architect when your project involves heritage constraints, complex structural conditions, a high construction budget, or when you want independent contract administration under an ABIC agreement. The Australian Institute of Architects (AIA) and ArchiTeam co-operative both operate find-an-architect directories.

Choose a building designer when your project is a relatively straightforward Class 1 residential project, budget is a primary consideration, and you're confident coordinating builder selection and contract administration yourself or through a project manager.

In either case, ask to see built work — not renders — before you commit. Design quality varies within both professions, and a portfolio of completed projects tells you far more than a registration number.