Intel
The Concealed, Recessed, and Flush Mounted Sprinkler Paradox
Want to get a bit nerdy about sprinklers? Stefan Germann, P.Eng., M.Eng, of our Vancouver office has put together a new blog post on the technical performance details of concealed, recessed and flush mounted sprinklers vs pendent sprinklers. If you like to get technical, then have a read!
celerity.ca
Lore
Osaka t.house
I am always interested to find projects like this design in Japan that could not be constructed in Canada as they have been designed due to the requirements of our Building Code. Adjustments to this design could be made to comply with the 2024 BC Building Code, but some of the character would likely be lost.
In order for this building to fit into the 2024 BC Building Code, particularly Part 9 to allow for avoiding sprinklers throughout, the following adjustments would be needed:
- the 2nd storey intermediate floor would have to be reduced in area so that it could be considered a mezzanine,
- the stair rises and runs would have to be adjusted to reduce the angle of the stairs, and
- guards would be needed to be added to all stairs and landings.
The reduced angle of the stairs would alter the layout, potentially to the point that the overall project layout would need to be reconsidered. The design stairs look to be almost ship ladders with how steep they are, which is not conducive to movement particularly for older persons.
The 2nd floor intermediate level could be retained or expanded, though this would create a four storey building. The impact as a 4-storey building would be the push into Part 3 the requirement to sprinkler throughout, in this case to NFPA 13 due to the commercial space on the 1st storey. Egress also becomes an issue, however, an alternative solution can be utilized typically to resolve this. Part 3 also introduces a maximum 6 m height between the lowermost and uppermost floor levels within the dwelling, though, this can be addressed with an alternative solution.
Do you have a 4-storey dwelling that you are designing? We would be please to help address the code challenges that are inherent to these designs.
archdaily.com
Wisdom
The Consequences of Overlapping Townhouses
The issue of overlapping townhouse designs has been coming up a lot lately on projects. I've had a few Architects recently reach out to clarify the typical application of the Building Code in this case. There is belief (or hope??) from some developers that small overlaps are acceptable without inducing additional spatial, construction, egress, and sprinkler requirements. This is unfortunate, as the code wording does not support this interpretation.
An overlapping dwelling unit townhouse design, no matter how small the overlap, is considered to create the condition of one dwelling unit above another. Where there is an overlap, the design can follow the regular prescriptive requirements of the Building Code, however, the typical relaxations afforded to townhouses that are not overlapped are no longer permitted.
The primary increased requirements are:
- Spatial is required to meet Subsection 9.10.14, instead of Subsection 9.10.15,
- All floor assemblies are required to be rated within the dwelling unit (always an issue with pot lights),
- A window 6 m above adjacent ground is not allowed for egress from the 3rd storey, and
- Sprinklers must be designed to NFPA 13R, instead of NFPA 13D when sprinklers are proposed or required.
A number of municipalities have issued bulletins or information circulars on overlapping dwelling unit townhouse designs, and all conclude that any overlap results in the dwelling units being considered stacked. The Surrey bulletin goes as far as to state some of the limits on an Alternative Solution that they will consider.
We have provided Alternative Solutions for overlapped dwelling unit townhouse designs many times in a number of jurisdictions, which allow for a reduction in the additional requirements. We would be pleased to help with your project, if you are running into challenges meeting the prescriptive code requirements.
surrey.ca
Recording: Passive Fire Protection - Firestop Systems
For those that missed our presentation at the end of May, here is the recording for you!
Gianni Vulcano, P.Eng., C.P., of our Victoria office, walks through the Part 3 requirements for firestopping, starting from a review of terminology and proceeding through specific details for firestopping joints, perimeters, service equipment penetrations, combustible pipes, and even outlet boxes.
This presentation was hosted by Nick Bray Architecture and presented by Celerity Engineering Limited.
youtu.be
Unsolicited Opinion
CBHCC Embodied GHG feedback
The Canadian Board for Harmonized Construction Codes (CBHCC) is looking for feedback on its embodied greenhouse gas emissions (GHG) policy. This is an important topic and I hope you all have strong opinions that you want to share!
The Building Code as it is written today, does not offer any real options for a fire engineer to significantly reduce the embodied GHGs when it comes to the fire safety requirements in a building. The only real avenue available is the specification of fire protective products that have a lower embodied GHG, which is very limited in impact.
The National Building Code of Canada is based on a series of Acceptable Solutions that provide a certain level of safety. Most of these Solutions originated prior to the first edition of the National Building Code of Canada in 1941 and were not based on scientific research, but rather the experience, perception, and ideas of the code writers at the time. There have been some fundamental changes made to the Solutions with the addition of interconnected floor space and high building provisions in the early 1970s, and the 6-storey wood frame, encapsulated mass timber, and single exit stair provisions in the last few years. Otherwise, changes have only been incremental improvements, and many solutions have not been revised to reflect current research and understanding.
In the 1990s, we did see improvement with the objective-based performance ideology being added but this was really just a framework laid over the existing Solutions. While this was helpful with the application of the Building Code, all performance approaches (Alternative Solutions) were, and still are, required to be benchmarked against the Acceptable Solutions. The implementation of the objective-based approach is discussed in the paper Canada’s objective-based codes, with the rationale for this decision. However, the decision to not allow a first principles approach severely restricts the fire engineer’s ability to propose alternative benchmarks that align with the project, current research, and accepted international practice, and typically results in significantly increased construction requirements that impact both building costs and embodied carbon within a building. In short, it holds our building industry back.
My colleague, Stefan Germann, P.Eng., M.Eng., based out of Celerity's Vancouver office, is an expert fire engineer who previously worked in New Zealand where they have had a performance-based, first principles approach Building Code since the early 1990s. Many of Stefan's projects in New Zealand and other parts of the world involved innovative solutions that minimized both construction cost and the embodied GHG while meeting the prescribed level of safety of the jurisdiction's Building Code. Unfortunately, to Stefan's frustration, many of those innovative solutions are currently impossible to implement in Canada.
Countries with a performance-based, first principles approach Building Code include New Zealand, Australia, the United Kingdom, the United Emirates, Japan, China, Indonesia, Singapore, and even the United States of America.
Please join Stefan and I in giving feedback on the proposed policy and pushing the CBHCC and politicians to get a first principles performance-based approach in our Building Code, so that we can really get to reducing construction costs and embodied GHG emissions!
cbhcc-cchcc.ca
