When a building is Class 1b
NCC 2025 clause A6G2 gives two descriptions. The first is a boarding house, guest house, hostel or the like that would ordinarily accommodate not more than 12 people and has a total area of all floors of not more than 300 m², measured over the enclosing walls. The second is four or more single dwellings on one allotment used for short-term holiday accommodation.
A boarding house above either limit is Class 3, which the rules also cover (see Class 3 building manuals).
The owner-operated exemption
Reg 205B(a) leaves out a Class 1b building only if it meets all five limbs:
- no more than 3 dwellings on the same allotment;
- an indoor area of 200 m² or less;
- used for short-term accommodation as a guest house or bed and breakfast;
- accommodation for no more than 6 guests;
- includes the owner's principal place of residence, and the owner runs the business.
A building that fails one limb is caught. An investor-owned rooming house fails limbs 3 and 5. Four or more holiday cabins on one allotment fail limb 1, so the short-stay form of Class 1b is always caught. The 2027 regulations guide covers the rest of reg 205B.
What a Class 1b manual involves
The 2025 Regulatory Impact Statement put a Class 1b manual at about 15 hours, half the Class 2 estimate, because the buildings are smaller and the documents simpler. It also noted that keeping a manual is not yet common practice for these buildings.
The draft goes in with the Form 15 occupancy permit application (s 41A) and is approved under s 41B. Reg 205A counts shared facilities outside the rooms as common areas, so assets in a shared kitchen, lounge or laundry belong on the asset list beside the fire safety systems, with location, replacement cost, maintenance schedule and service life. On land with no owners corporation, the owner keeps the manual and updates it on Form 26 by the 14th day after each approval anniversary (s 44C, reg 205F), with any reg 223 AESM report attached.
What building surveyors check explains the completeness test, and annual updates covers Form 26.
What we compile for a Class 1b building
A Class 1b compile falls in the small band: indicatively $2,500 to $6,000 ex GST, or $400 to $900 for a completeness audit of documents you have already gathered. You get the draft indexed to reg 205C, in .pdf and .xlsx files (reg 205G).
Questions
What size limits put a building in Class 1b?
Under NCC 2025 Part A6 (clause A6G2), a boarding house, guest house or hostel is Class 1b if it would ordinarily accommodate not more than 12 people and has a total floor area of not more than 300 square metres, measured over the enclosing walls. Four or more single dwellings on one allotment used for short-term holiday accommodation are also Class 1b.
Which Class 1b buildings are exempt from the Victorian building manual rules?
Under Regulation 205B(a), a Class 1b building is exempt only if it meets all five conditions: no more than 3 dwellings on the same allotment, an indoor area of 200 square metres or less, use as a guest house or bed and breakfast, no more than 6 guests, and it includes the owner's principal place of residence with the owner operating the business.
Do four short-stay cabins on one block need a building manual?
Yes, if the building permit application is made on or after 1 February 2027. Four or more single dwellings on one allotment used for short-term holiday accommodation are Class 1b, and the exemption in Regulation 205B(a) allows no more than 3 dwellings.
Sources: NCC 2025 Part A6 (A6G2, A6G4); S.R. No. 87/2026 (regs 205A, 205B, 205F, 205H); Building Act 1993 (Vic) ss 41A, 41B and 44C; 2025 Regulatory Impact Statement, section 2.5.4.