CAN-ASC-2.11 – Accessible-Ready Modular and Prefabricated Housing
12. Interior structural design
Information
Table of contents
Technical committee members
- Amy Pothier Kelly, Senior Manager, Customer and Inclusive Design, Metrolinx
- Brad Humphrey, Architect, AIBC, Jensen Hughes
- Brieann Ventura, Building Code and Accessibility Consultant, LMDG Building Code Consultants Ltd.
- Christelle Montreuil, Founder and Senior Consultant in Inclusive Design and Universal Accessibility, Idéaux
- David Pereyra, Project & Outreach Coordinator, Inclusive Design Research Centre. OCAD University
- Dominic Esposito, Senior Project Consultant, Jensen Hughes
- Harold Locke, Consultant, Locke & Locke Inc.
- Julie L. Sawchuk, Principal, Sawchuk Accessible Solutions
- Linnie Tse, Provincial Barrier-Free Administrator, Government of Alberta
- Monica A. Contreras, Senior Manager, Facilities Infrastructure, Lead Architect Architectural Project Delivery, Bell Canada, Bell Real Estate Services
- Philip Rizcallah, Chief Executive Office, Engineers Canada
- Samiddha Aryasinghe, Senior Project Manager, Tiree Facility Solutions Inc.
- Sherry Hastings, Functional Planner – Capital Planning, Saskatchewan Health Authority
- Taghreed Al-Zubaidi, Accessibility Specialist, City of Mississauga
12.1 Load-bearing walls
Where an interior load-bearing structure is required, it shall:
- use a post and beam system (i.e. columns and beams) instead of an interior load-bearing wall;
except as provided in item c) of this Clause, have a clear span between columns:
- of at least 4,200 mm; or
- extend the full length of the wall section being replaced; and
Note: The minimum clear span requirement between columns specified in item b) of this Clause may be reduced to 3,000 mm. The reduced clear span of 3,000 mm, is based on a typical 3‑ply 38 mm × 235 mm beam with a supported length of 2,400 mm.
- if all rooms and spaces adjacent to the load-bearing structure maintain compliance with the spatial and circulation requirements of CSA/ASC B652:23, including:
- clause 4.4.1 Accessible paths of travel;
- clause 4.4.2 Clear floor spaces;
- clause 4.4.3 Knee and toe clearances;
- clause 4.5.2 Floor area;
- clause 5.7.2 Manoeuvring area at doors;
- clause 5.7.3 Two doors in series;
- clause 5.8.1 Accessible path of travel—Horizontal;
- clause 5.9 Bathroom(s);
- clause 5.10 Kitchens;
- clause 5.11 Bedrooms;
- clause 5.12 Laundry;
- clause 5.14 Home automation; and
- clause 5.15 Service rooms and spaces;
Note 1: Modular construction may require, for fabrication, transportation, or installation purposes, the construction of load-bearing walls, doubled walls, or other interior load-bearing structures.
Note 2: Minimizing the use of load-bearing interior walls can make it more straightforward to reconfigure interior spaces without major structural changes.
Note 3: Avoid installing mechanical, electrical, plumbing, and HVAC systems within interior walls to facilitate removal or modification for creating accessible paths of travel, without significant changes.
12.2 Service chases
12.2.1 Vertical service chases
To facilitate future changes to the space, services (HVAC, plumbing, electrical, etc.) shall:
- be grouped together by floor generally in a maximum of two groups, unless design circumstances require additional groupings (e.g. all services running from the basement level to a second storey can be grouped together in a single group, or into one group on each side of the home);
- be installed within a designated vertical service chase with minimum dimensions of 89 mm × 360 mm;
- include access panels or hatches within the vertical chase to allow for the installation of additional services or modification of existing ones;
- have the vertical chases located in walls or areas that do not require modifications based on the DAR; and
- have the vertical chases clearly documented in the DAR form and drawings.
12.2.2 Horizontal service chases
To facilitate future changes to the space, services (HVAC, plumbing, electrical, etc.) shall:
- be grouped together by floor area in a maximum of two groups per 100 m² of floor area (e.g. all services going from the vertical chase to the adjacent bedrooms on the second storey can be grouped in a single group);
- be installed in a designated horizontal service chase with minimum dimensions of 180 mm × 300 mm (clear interior dimension);
- have the horizontal chases located in walls or areas that do not require modifications based on the DAR; and
- have the horizontal chases clearly documented in the DAR form and drawings.
Note 1: Joist or truss cavities may be used as horizontal chases. Access hatches should be provided.
Note 2: Because of factory construction and transport requirements, modular and prefabricated housing may use double floor joist construction between floors. Where this technique is used, an access between the ceiling level and floor level should be provided where a horizontal service chase is installed.