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What does Class 1b certification actually require for a nine-room co-living property in Victoria?

· Yannick Ieko

Answering: What does Class 1b building certification actually require for a nine-room co-living property in Victoria?

Estimated reading time: 12 min read

Class 1b requires a building that fits the National Construction Code’s limits, which in the Code’s words cover “a boarding house, guest house, hostel or the like” that “would ordinarily accommodate not more than 12 people” with a total floor area “not more than 300 m2”, approved as Class 1b by a building surveyor. If a nine-room property cannot show you the permits that record that approval, it is not a fit for a co-living investment, whatever the yield sheet says.

Class 1b is a building classification, not a marketing badge. It describes the fabric, the fire safety and the approved use of the building. It says nothing on its own about who runs the property or how.

The Harmony Group confirms Class 1b certification on every property before a client commits.

Key Insights

  • Class 1b is defined by the NCC: not more than 12 people ordinarily accommodated, not more than 300 square metres of floor area.
  • Beyond those limits, a boarding house or hostel is generally Class 3.
  • A building surveyor approves the use through the building permit and, where required, an occupancy permit.
  • Fire safety and essential safety measures come with the classification and are inspected.
  • Class 1b certifies the building, not the operator.

Table of Contents

What the National Construction Code actually says Class 1b is

Most of what is written about Class 1b paraphrases it. The definition itself is short. The National Construction Code (NCC), in Part A6 of Volume One, says Class 1b is one or more buildings which together constitute:

  • “a boarding house, guest house, hostel or the like that would ordinarily accommodate not more than 12 people; and have a total area of all floors not more than 300 m2 (measured over the enclosing walls of the building or buildings)”; or
  • “four or more single dwellings located on one allotment and used for short-term holiday accommodation”.

The second limb is about holiday cabins and is not the co-living case. The first limb is.

Two numbers do the work: 12 people and 300 square metres. A boarding house or hostel that goes past either limit falls outside the Class 1b concession and into Class 3, which the NCC describes as “a residential building providing long-term or transient accommodation for a number of unrelated persons”. The NCC also sets a limitation for every Class 1 building: it “cannot be located above or below another dwelling or another class of building, other than a private garage”.

You will often read that Class 1b is “for four or more unrelated tenants”. That number does not come from the NCC definition. It comes from Victoria’s definition of a rooming house, which Consumer Affairs Victoria (CAV) describes as “a building where one or more rooms is available for occupancy by four or more people (in return for the payment of rent)”. The four-person trigger brings the property into the rooming-house regime. The NCC’s ceilings decide whether the building can sit in Class 1b. A nine-room proposal has to answer both.

The text above is the same in the 2022 and 2025 editions of the NCC.

How a building gets approved as Class 1b in Victoria

Classification is not a certificate you buy at the end. It is decided by a registered building surveyor against the plans and then against the finished building.

In Victoria, building work needs a building permit, and the permit “will specify if you need an occupancy permit from your appointed building surveyor”, according to the Australian Government’s business licence information service for Victoria. An occupancy permit “confirms your building surveyor is satisfied the building is suitable for occupation”. The framework sits under the Building Act 1993 and the Building Regulations 2018, and the administering agency listed is the Building and Plumbing Commission.

That is building approval, not land-use approval. Whether the use needs a planning permit, or meets the planning exemption for small rooming houses, is a separate question under the planning scheme, covered below.

For a purpose-built nine-bed, the building approval is designed in from the first drawing. The building surveyor assesses plans drawn for a Class 1b use, inspects the work as it is built, and is satisfied at the end that the building is suitable to be occupied for that use.

For an existing house being put to use as a rooming house, the question is different: has a building surveyor been satisfied that the building is suitable for its new use, and where is the paper that says so? Our comparison of purpose-built co-living and HMO conversions sets out how the two paths differ for an investor. Either way, the classification belongs to the approved building, so an investor should ask to see the building permit and occupancy permit, and confirm with the issuing surveyor which classification they record.

The fire safety and essential safety measures that come with it

A Class 1b building carries more safety obligation than a family home because unrelated people sleep in it. Some of that obligation is built in. Some of it has to be maintained and recorded for as long as the building is used.

What CAV says is checked or required in a Victorian rooming house:

  • Smoke alarms. “Rooming houses must have hard-wired smoke alarms.” Residents must not disable them, and a faulty alarm is fixed as an urgent repair.
  • Fire safety inspections. CAV says a building fire safety inspection may also be conducted by the fire services (its page names the Metropolitan Fire Brigade, which became part of Fire Rescue Victoria in 2020, and the Country Fire Authority), looking at matters including “fire prevention systems, including smoke detectors” and “emergency lighting and exits”.
  • Essential safety measures. “Operators must keep records of maintenance of essential safety measures and the current essential safety measures report, as these are likely to be requested during an inspection.”
  • Building notices and orders. A municipal or private building surveyor “may issue an operator with a building notice or building order if they believe the rooming house does not comply with the Building Regulations and is therefore unsafe”.
  • Ventilation and evacuation. The rooming-house minimum standards require ventilation that complies with the relevant Building Code of Australia and an evacuation diagram complying with AS 3745 in each resident’s room and shared area.

The practical point for a buyer: Class 1b is not only a design standard. It creates maintenance records that someone has to keep. A property whose safety records cannot be produced has a gap, even if its permits are in order.

What Class 1b does not cover

This is where most confusion starts. A Class 1b classification is about the building. It is not a licence for the person running the property, it does not register the property with council, and it does not settle tax.

Three separate things sit beside it in Victoria:

  • The operator licence. CAV says operators “must apply for, and be granted, a licence before they can start operating a rooming house”, granted by the Business Licensing Authority.
  • Council registration. Premises are registered with the local council under the Public Health and Wellbeing Act 2008.
  • Operating standards and records. The rooming-house minimum standards apply to the property as it is run, and operators now carry a record-keeping duty that began on 13 October 2026.

Our September guide to licences, council registration and Class 1b takes the approvals in turn, and our guide to rooming-house operator duties and records since 13 October 2026 covers what the operator has to keep once residents move in. If your question is how to check all of this on a specific offer before you pay anything, our Class 1b verification checklist lists the documents to sight.

On tax, the answer is short. Class 1b certification is a building classification and is not linked to tax status. For the 2027 negative gearing reform, read what the 2027 negative gearing changes mean for property investors separately.

How The Harmony Group builds Class 1b into the product

The Harmony Group’s product is a high-end, purpose-built nine-bed co-living property: nine rooms, nine bathrooms, single storey, on one title. It is designed for Class 1b from the start rather than adapted to it later.

Three parts of the process carry the certification question:

  • Property Specification. The team’s 118-point method has three pillars: Market Analysis (42 points), Area Selection (38) and Property Specification (38). Specification is where the building itself is assessed.
  • Confirmation before commitment. The classification is checked and confirmed before any client commits. The company reports that none of its delivered properties has had a legal or certification issue.
  • The build partners. The Harmony Formula’s build stage uses an exclusive partner network of specialist architects, the builder, hotel fit-out specialists and specialist property managers. Each build carries a 7-year structural guarantee, plus a 3-month maintenance inspection and warranty period.

The team brings 15+ years of specialist accommodation experience to that work. We build in Melbourne. Our investors come from every state.

If you want the planning side, which is a separate system from building approval, read why nine bedrooms is the limit for a Victorian rooming house without a planning permit.

Frequently asked questions about Class 1b requirements

Q: Does Class 1b mean the property can house four or more unrelated tenants?

Not by itself. The NCC defines Class 1b by ceilings: a boarding house, guest house or hostel that would ordinarily accommodate not more than 12 people, with not more than 300 square metres of floor area. The “four or more” figure is Victoria’s rooming-house trigger, which brings in operator licensing, council registration and minimum standards. A nine-room property has to satisfy both sets of rules.

Q: What happens if a building goes past 12 people or 300 square metres?

It falls outside the Class 1b concession. The NCC treats larger boarding houses, guest houses, hostels and lodging houses as Class 3, a different classification with its own requirements. Ask the building surveyor which classification the building was approved under rather than assuming from the room count.

Q: Who issues Class 1b certification in Victoria?

A registered building surveyor, municipal or private, through the building permit and, where the permit requires it, an occupancy permit. The occupancy permit confirms the surveyor is satisfied the building is suitable for occupation. The Building and Plumbing Commission administers the framework under the Building Act 1993 and Building Regulations 2018.

Q: Is Class 1b certification enough to operate a rooming house?

No. The classification is about the building. Running it as a rooming house also takes an operator licensed by the Business Licensing Authority, premises registered with council, and a property kept to the rooming-house minimum standards.

Q: Does Class 1b certification affect how a property is taxed?

Class 1b is a building classification and is not linked to tax status. Tax treatment, including under the 2027 negative gearing reform, is a separate question for your own tax adviser.

Start with the building, then the numbers

A yield figure is only as good as the building’s right to house the people paying it. That is why the first question about any nine-room offer is the classification and the paper behind it, and the second is who operates it.

The free co-living education program starts with the asset itself: what you would own, and how a purpose-built nine-bed is designed and run. The core of it is roughly 45 minutes of your time. Once you have completed any nine modules, a booking link opens for a one on one with a director. If co-living isn’t suitable for you, we’ll tell you why.

Citations

  • NCC 2025 Volume One, Part A6 Building classification, Australian Building Codes Board. The A6G2 Class 1b definition (not more than 12 people, not more than 300 square metres), the Class 1 location limitation, and the A6G4 Class 3 definition; wording identical in NCC 2022.
  • Occupancy Permit, Building Work, Victoria, Australian Business Licence and Information Service. The building permit specifies whether an occupancy permit is needed; the permit confirms the building surveyor is satisfied the building is suitable for occupation; Building Act 1993 and Building Regulations 2018; administered by the Building and Plumbing Commission.
  • Rooming house inspections, Consumer Affairs Victoria. Council, CAV, health, building and fire safety inspections; essential safety measures records; building notices and orders.
  • Smoke alarms and fire safety, Consumer Affairs Victoria. Rooming houses must have hard-wired smoke alarms.
  • Rooming house minimum standards, Consumer Affairs Victoria, last updated 14 October 2026. The record-keeping duty from 13 October 2026, ventilation and the AS 3745 evacuation diagram.
  • Rooming house definitions, Consumer Affairs Victoria. A rooming house is a building where one or more rooms is available for occupancy by four or more people.
  • Rooming house operators licensing scheme, Consumer Affairs Victoria. Operators must be licensed by the Business Licensing Authority before operating; council registration under the Public Health and Wellbeing Act 2008 is a separate obligation.

General information only. The Harmony Group provides general information about property and co-living investment, not personal financial, tax or legal advice, and does not hold an Australian Financial Services Licence (AFSL). It does not account for your objectives, financial situation or needs, so consider its appropriateness and seek advice from a licensed financial adviser, mortgage broker, accountant or the ATO before acting. Past performance is not a guide to future results and historical figures may not be repeated. The 2027 negative gearing reform was enacted on 26 June 2026 and applies from 1 July 2027. The definition of a new residential dwelling is still being settled after Treasury’s consultation, so whether a nine-bed is an eligible new build remains unsettled. Other tax or regulatory measures described are subject to change.