What Is a Class 1b Building? Modular Accommodation Explained (2026)

October 2026

A Class 1b building under the National Construction Code is a small boarding house, guest house, hostel or similar shared accommodation that stays below the floor area and occupant limits the NCC sets. A group of single dwellings on one allotment used for short-term holiday accommodation can also be Class 1b. Once shared accommodation goes over those limits it is usually Class 3, which carries tougher fire and access requirements.

This page is for farm and orchard owners, mine and energy operators, holiday park owners, councils and builders across Australia planning modular accommodation. The problem is that the class sets most of the building rules, and it is easy to plan a camp or a block of rooms that slides from Class 1b into Class 3 as numbers grow. That changes the fire separation, the access provisions and sometimes the whole design.

How Class 1b differs from a house and from Class 3

Class 1a is a single home for one household.
Class 1b is small shared accommodation, or a group of short-stay holiday dwellings on one allotment, below the NCC limits. It has more fire safety and access requirements than a house.
Class 3 is larger shared accommodation, such as motels, hostels, student housing and larger workforce villages. It brings fire-rated separation between rooms, more egress requirements and more access requirements.
Workforce accommodation is typically Class 1b or 3, confirmed by your building surveyor.

The exact limits and the provisions that apply are in the NCC volume your surveyor works to. Do not set the number of beds before your building surveyor has confirmed which side of the line the project sits on.

Where Class 1b shows up in modular projects

Small farm worker houses, a guest house wing on a rural property, a short-stay cabin group in a holiday park, and a small staff house at a remote site are common Class 1b projects. Queensland has a planning pathway for one of these. Under the Rural Workers’ Accommodation Initiative, Part B covers small-scale rural workers’ accommodation on rural land of 25 ha or more for no more than 20 rural employees, with no material change of use approval needed if the criteria are met; Part B runs to 16 December 2027 (QLD Planning, Planning Amendment Regulation 2025). Building approval is still required. Our page on seasonal worker accommodation options compares the choices.

Larger camps tip into Class 3. The Pilbara Development Commission counted 80,432 workforce accommodation beds in December 2025, projected to reach 91,435 by 2028. Villages at that scale are planned and approved as larger accommodation buildings, not as a set of small houses. See our page on modular workforce accommodation in WA.

Why modular fits Class 1b accommodation

Class 1b buildings are usually made of repeated rooms with ensuites or a shared bathroom and kitchen. Those are exactly the parts a volumetric module carries well. Fire detection, wet areas and the room fit-out are built and inspected in the factory before the modules leave, so the site work is mostly footings, connections and services.

What EcoPrestige supplies

EcoPrestige supplies engineered structural steel volumetric modules, built and inspected in an offsite factory, for accommodation buildings. Typical modules are ensuite rooms, shared kitchens and laundries, and managers’ units, laid out to suit the class your surveyor confirms. Our page on modular accommodation unit sizes and layouts shows common room types.

What does not fit

If you need rooms for one season and then gone, hire. If the site cannot take a truck and crane, larger modules may not reach it. And a modular building does not change the class: the rules for a Class 1b or Class 3 building apply in full however it is built.

The approval path

The building surveyor or certifier confirms the class and certifies the building. EcoPrestige coordinates the module design with your consultants; permit drawings are issued by the registered or licensed practitioner the state requires. In Queensland, permit drawings are issued under a QBCC licensed building designer, and in Tasmania by a licensed Tasmanian building designer. Planning approval depends on the zone and the local scheme.

The programme

Confirm the class, then design and approve. The factory builds the rooms while the builder prepares footings and services, so factory and site work run in parallel and time on site is shorter.

What to send us

1. The site address and the zone, if you know it.
2. How many people will sleep there, and for how long each stay.
3. Who they are: staff, seasonal workers, guests or contractors.
4. Shared or private bathrooms and kitchens.
5. Any drawings, or advice already given by a surveyor.

Class 1b buildings: questions buyers ask

What is a Class 1b building?
A Class 1b building is small shared accommodation, such as a boarding house, guest house or hostel, that stays below the floor area and occupant limits set by the NCC. A group of single dwellings on one allotment used for short-term holiday accommodation can also be Class 1b.

What is the difference between Class 1b and Class 3?
Class 3 covers larger shared accommodation such as motels, hostels, student housing and larger workforce villages. It carries tougher fire separation, egress and access requirements than Class 1b.

Is workforce accommodation Class 1b or Class 3?
Workforce accommodation is typically Class 1b or 3, confirmed by your building surveyor. Small staff houses tend to be Class 1b and larger camps Class 3.

Can a Class 1b building be modular?
Yes. A Class 1b building can be made of volumetric modules, but it must meet the same NCC requirements as a site-built Class 1b building.

Does a Class 1b building need a building permit?
Yes. It needs building approval like any permanent building, and planning approval where the zone or local scheme requires it.

Related: our guide to AS 3740 wet area waterproofing.

Related: our guide to modular accommodation in NSW.