Design Guidelines for alteration of a typical residence (Class 1) into an office (Class 5) , details for inclusion in a "Change of Classification" Development Application, including consideration of Building Code of Australia (BCA) requirements.
ADDITIONAL ITEMS TO CONSIDER AS PART OF THE DEVELOPMENT APPLICATION DOCUMENTS
- On the development application form it is important that the number of employees /occupants is correctly filled (by gender) in the space provided as the required amount of amenities (and whether they are permitted to be unisex) relates to these figures.
- On the floor plan clearly show any existing walls proposed to be demolished and any new walls proposed to be erected. Distinction should be made between full height walls and partition height walls and also between load-bearing and non-loadbearing walls.
GENERAL PROVISIONS (Part A of the BCA.).
- Clearly nominate the proposed uses of rooms /areas on the floor plan. For mixed classifications clearly show the use of any non-office area).
STRUCTURAL MATTERS (Part B of the BCA)
- Where structural supports are required (e.g. for existing roof loads over proposed new openings) in the nature of beams / lintels/ columns, sufficient details are needed to show what loads are placed on them and the member construction. Structural engineers calculations may be required where lintel spans or loads exceed the table given in the BDA specification.
FIRE RESISTANCE (PART C of the BCA)
- Where side walls are within 3 m of a site side or rear boundary (not street side) provisions for achieving the required fire resistance levels for walls /openings windows need to be shown.
- In some instances existing windows can be bricked up with fire rated glass blocks. The required amount of ventilation being provided by an alternative location (or by a mechanical system).
- 60 min. rated glass blocks or 90 min. rated glass blocks will give the required rating depending on the windows proximity (90 min. if closer than 1.5 m) to the boundary.
- The alternative method of choosing wall wetting sprinklers at the window locations is becoming more accepted by Councils..
ACCESS & EGRESS (Part D of the BCA)
- Show how access to the building for disabled persons will be achieved on the plan including any change of level ramping details (all in accordance with Aust. Std. 1428 Pt.1 1993).
- Any existing or proposed stairs are to be indicated on the plans along with sufficient details to show how compliance with Part D of the BCA will be achieved.
- External doors serving as a required exit are to be clearly shown on the plan including their direction of swing. Specification /schedule mentioning the type of locking/latching mechanism of the doors where required by BCA Reg D2.20 & D2.21 are to be prepared..
- Provide a disabled persons carparking space(s) D3.5
- Provide appropriate signage for disabled persons D3.6
FIRE FIGHTING EQUIPMENT (Part E of the BCA)
- Fire extinguisher locations and types nominated on the floor plan. No part of the floor to be more than 15m from an extinguisher.
- Further fire safety matters may be required by the Council.
AMENITIES (Part F of the BCA).
- Disabled persons amenities should be shown on plans and specified in accordance with Aust. Std. 1428 Pt. 1 1993. Prepare elevation drawings of the internal layout/ handrails etc. The minimum size requirements in AS 1428 preclude an average sized w.c. from being used.
- Required amounts of employees locker space may be required to be shown in accordance with BCA Reg. SA F 2.101.
- Any proposed construction of further (or revised) wet areas should be clarified by including relevant wet area construction details in accordance with Minister's Specification SA F 1.7.
NOTE: This document is intended as preliminary / general advice only and is not a substitute for individual assessment (by a Building Designer’s Association member) for a specific site proposal.
Copyright - Allan E. Johanson & Associates Building Designers and Consultants