Determinations issued
Determination 2007/81
Fire safety in a building consent for a building converted into four new apartments.
The matter for determination
The application arose from a dispute about the territorial authority's decision to issue a building consent with certain conditions.
The territorial authority was not satisfied the following elements complied with the Building Code.
- Keeping the existing south wall windows that are within a metre of the site boundary
- The horizontal safe path at the entry of a lower apartment
The owner applied for the determination.
The building work
The building work comprises converting a lodge/hall building into four new apartments. Eight existing timber, double-hung, sash windows on one brick-faced boundary wall have a separation distance from the external faces of the glass to the site boundary of between 925 mm and 975 mm. The owner proposed to keep the existing windows in these walls in their locations.
The territorial authority asked for the windows to be provided with fire-resistant glazing and automatic closing and latching devices. While the windows had to be re-glazed, the frames could be kept.
The proposed means of escape from fire consists of independent access to the outside from one ground floor apartment and a shared main entry for the remaining three apartments, which doubles as the vertical safe path access to the upper apartments.
The submissions
The owner stated that, while the windows in question were about 890 mm from the boundary, the neighbours' house was 2040 mm from the conversion. The owner considered the question of escape from fire had been covered in a previous report sent to the territorial authority.
A firm of fire engineers employed by the owner provided a further submission, noting there was only a small margin by which the windows did not comply with the required separation distance. The neighbouring property was located 1150 mm and 3650 mm from the common boundary at the lower floor level and the upper floor of the conversion was clear of the neighbours' house. The only practical option to meet the escape from fire concerns was to provide a horizontal safe path, which would need two fire doors close to each other. A short horizontal safe path would be 'abused' by the occupants and the resulting lobby seemed to be superfluous.
The territorial authority did not make a submission.
The draft determinations
The Department sent a draft determination to the parties and both accepted the draft without comment.
The final determination
The final determination discussed the following major issues.
Compliance ‘as nearly as is reasonably practicable’
A decision on whether any upgrade will make the building comply as 'nearly as is reasonably practicable' with the Building Code rests on weighing the cost and other sacrifices involved in the upgrade against the benefits achieved. The High Court described the process in Auckland City Council vs New Zealand Fire Service.
The Department decided the conversion had only to comply, as nearly as reasonably practicable, with Building Code provisions on the means of escape from fire and fire-rating performance.
The existing windows
The resource consent required the existing windows not to be changed in appearance and noted that a new resource consent was required for any alteration to them. Although this matter could be considered part of the 'benefit and sacrifice' equation, it was one within the ambit of the Resource Management Act 1991 and not the Building Act 2004, so did not form part of the determination. The applicant noted the window-to-boundary separation dimensions were less than the Code-stipulated 1-metre separation. However, the Department noted that Building Code Clause C3 did not mention any such dimensions. The dimensions described by the fire engineers are set out in C/AS1, which is not part of the Building Code. While it describes methods for achieving Code compliance, it does not prevent the consideration of other alternatives.
The applicant submitted that, considering the depth of the window reveals from the face of the south wall, the distance from the window glass faces to the boundary varied between 925 mm and 975 mm. However, the Department noted that in C/AS1, step 6 of Method 2 (enclosed rectangles) for deciding the required distance stated the distance was to be taken from 'the external wall to the relevant boundary'. As the Department considered that a separation distance of 750 mm was the correct one to use to calculate the fire resistance rating of the windows, this dimension did not achieve the 1-metre distance as required in C/AS1.
The Department noted the building consent allowed the 'frames' of the windows to remain as they were. If a wide meaning were given to the word 'frame', it could be interpreted to include the sashes. The consent also only required the windows to be 're-glazed' without any mention of the sashes themselves.
The Department believed that merely to re-glaze the windows would not be enough to meet the -/30/-Sm requirement. Further work would be needed to the sashes and perhaps the surround frames. It was likely that one amended window would have to be removed and tested by an approved organisation to ensure its compliance with the territorial authority's requirement.
The Department also accepted that installing automatic closing and latching devices was required for the windows to be Code-compliant.
The Department determined the windows were not Code-compliant in their present state and needed major changes to comply. The applicant had provided an estimated cost of $10,678 for the work required by the building consent, and referred to extra detrimental issues should the windows be removed or replaced.
The Department accepted that amending or replacing the windows, or adopting acceptable alternatives could be difficult. However, there were clear considerations of human safety in this case, in particular, the safety of the occupants of the neighbour's building should a fire start in the conversion. The Department had to give suitable weight to the human safety benefits achieved by amending or replacing the windows and decided that those safety benefits outweighed the sacrifice involved.
The horizontal safe path
The Department decided the proposed means of escape from fire for the outside access did not meet the requirements of Clause 3.3.3. It considered that adding a further set of fire doors or an approved alternative would not be a heavy burden on the applicant, considering the safety benefit and sacrifice. Nor could it accept that any perceived 'abuse' of the safe path was relevant for safety. Therefore, the proposed means of escape needed to be amended to meet the territorial authority's concerns.
The decision
The Department:
- determined the following did not comply as nearly as is reasonably practicable with the Building Code:
- keeping the existing south wall timber windows that are within 1 metre of the boundary
- the horizontal safe path at the entry of the lower apartment at the southern end of the building
- confirmed the territorial authority's decision to issue the building consent that contained an attachment to the consent.
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