NSW – HENDRY building certifiers were engaged by a building owner to prepare a BCA Audit (not a comprehensive BCA Audit) on a large office/factory premises. The purpose of an abridged BCA Audit was for the building owner to provide to potential purchasers of the premises a ‘BCA Audit’ listing major criteria of non compliance with the Building Code of Australia (BCA) that a purchaser would need to account for in any future occupation of the building.
Attention: Mr XXXX
Re: BCA Audit for Office/Warehouse Premises at XXXXXX
In accordance with your requirements, we undertook an inspection for the purposes of a BCA Audit of the abovementioned premises on XXXX 2003 for the purpose of providing advice on the building’s compliance status with the Building Code of Australia (BCA).
We note that, as required and due to the time constraints, this BCA Audit is not intended to be a comprehensive report, but rather aims to identify major issues of departure from the BCA which may be of significance to a potential purchaser, particularly where building alterations and/or a change of use may be proposed.
The version of the BCA against which this BCA Audit is made is the current version of BCA XX incorporating the NSW Variations and Amendment No. XX (adopted in NSW on 1 January 20XX).
Building Description – BCA Audit
The existing building, which is currently vacant, consists of a two-storey office portion plus a high volume warehouse portion with carparking beneath.
The construction of the building comprises reinforced concrete floor slabs and columns, external walls of pre-cast tilt up panels, masonry and glass external walls and sarked metal deck roof. The warehouse roof is supported by structural steel beams which are in turn supported in the main by reinforced concrete columns and some structural steel columns (internal).
The XXXX external wall is approximately 1.2m off the boundary, the XXXX external wall is at least 3m from the boundary and the XXXX external wall is in close proximity to the boundary.
Egress for the building consists of:
- two stairs serving the first floor office;
- ground floor office exits via eastern and southern facade doors;
- warehouse exits via two exits on the eastern side which discharge directly to outside and two exits on the western side which discharge to the carpark level below.
The carpark level, having an estimated floor area/volume of XXXXXX, forms a separate fire compartment from the rest of the building.
The carpark level is naturally ventilated via a ventilation shaft in the XXXXX corner and open sides on the northern and eastern elevations, the northern elevation being set back at least 3m from the boundary.
The office and warehouse form a single fire compartment with areas and volumes estimated as follows:
– TABLE DELETED –
Fire safety measures in the building consist of:
- Fire hydrants, including a hydrant pump at the northwestern corner of the carpark level and a fire brigade booster assembly adjacent to the carpark entry;
- Fire hose reels;
- Portable fire extinguishers;
- Fire doors to the two western exits serving the warehouse;
- Exit signs;
- Wired glass windows in steel frames (presumably -/60/- FRL fire windows) in the southern elevation;
- External wall wetting sprinklers to the curtain wall section of the southern elevation.
BCA Audit Compliance Matters
BCA Audit: Departures from compliance with the deemed-to-satisfy provisions of the BCA are listed as follows:
1. The combined floor area/ volume of the office/ warehouse compartment has been estimated at approximately XXXX/XXXX. This is consistent with the areas listed on the signboard at the front of the building of XXXX for the office component and XXXX for the warehouse component resulting in an aggregate floor area of XXXX.
This is of relevance to the Type of Construction requirements applicable to the building which in turn is influenced by the size of its largest fire compartment.
In this regard, for a Type B Construction building a maximum fire compartment size of XXXX is permissible, which the building currently approximates.
If the compartment size was to increase beyond these limits, for example by raising the warehouse roof height, then the building would fall under the Type A Construction requirements with a floor area/ volume limitation for the largest fire compartment of XXXX.
The significance of Type A Construction is the requirement for higher fire resistance levels (FRLs) for building elements such as the first floor slab and supporting members. A 240/240/240 FRL would be necessary, this being driven by the FRL requirements arising from the warehouse component and the lack of firewall separation between the warehouse and office parts. It is unlikely that the first floor structure would satisfy a 240/240/240 FRL, although other mitigating measures may be feasible such as providing a 240/240/240 FRL firewall between the warehouse and office or by installing an automatic sprinkler system throughout. The use of sprinklers as a trade-off in this manner would have to be justified as an Alternative Solution by Fire-Engineering Analysis, however it is to be expected that this would be feasible.
2. The building is not provided with either a fire detection and alarm system or an automatic sprinkler system.
This is acceptable under the BCA for the office component, when considered in isolation, as it does not have a rise in storeys of more than two.
For the warehouse component however, because it has a floor area greater than 2000m² and a volume of more than 12,000m³, Table E1.5 of the BCA specifies the requirement for sprinklers where goods exceeding an aggregate volume of 1000m3 can be stored to a height greater than 4m.
Clearly then, as far as the BCA is concerned, sprinklers would be necessary if the stored height is intended to exceed 4m.
Sprinklers would then definitely be required if it is proposed to extend the height of the roof.
3. As the warehouse is not separated from the office component by a 240/240/240 FRL firewall, the installation of sprinklers in the warehouse would necessitate their installation throughout the two office levels.
4. The installation of an automatic sprinkler system would necessitate compliance with
AS 2118.1. This may also necessitate the installation of an on-site water storage tank and pump where the mains are not able to meet the minimum flow and pressure required by the code. The required tank capacity could be in the approximate vicinity of 200,000 to 300,000 litres. For advice on this matter, it would be necessary to engage a Fire Services Consultant.
5. Any proposed increase in the roof height of the warehouse will necessitate the installation of fire resistant infill panels to the resultant openings at the top of the external walls of the western elevations and part of the northern elevation within 3m of the western boundary, i.e. sheet metal infill panels would not be acceptable.
6. Exit travel distances generally appear to be satisfactory on the two office levels and carpark level except that:
– The ground floor exit door in the southern elevation is locked from within and is therefore non-compliant;
– Travel distance from the first floor boardroom is marginally excessive, although this is not considered to be of major significance;
– Any proposal to install security mesh to the perimeter of the carpark would necessitate the installation of strategically placed exit doors, to be determined.
7. Exit travel distances are satisfactory in the warehouse on an open floor plan basis, as is currently the situation. Proposed racking, stacking areas etc. would need to be established for compliance with the 20m/40m/60m travel distance limitations of BCA D1.4 and BCA D1.5.
8. The balustrade to the XXXX stair at first floor level is non-compliant in that it is approximately 900 mm high in lieu of the minimum required height of 1000 mm and has openings which exceed the maximum size which would allow a 125 mm diameter sphere to pass through.
9. Although the building is equipped with exit signage, there is no evidence of emergency lighting, other than for one emergency light in the northwestern XXXX. Emergency lighting is necessary in the warehouse, within stairs, and within at least the office corridors.
10. Existing fire safety measures in the building comprise hydrants, hose reels, portable fire extinguishers, fire doors, exit signs, fire-rated windows and external wall wetting sprinklers. There should be available an Annual Fire Safety Statement to confirm that these measures are being maintained in accordance with the standard in force at the time of installation.
We trust that these comments address your immediate requirements and would be pleased to provide further advice as necessary.
Should clarification be necessary on any of the above comments, please do not hesitate to contact this office.
Hendry Group (NSW) Pty Ltd