Proposed Change 1884

Being able to access the main living spaces in a dwelling unit is essential for both residents and visiting friends and family. However, because of the existing shortcomings of the NBC requirements, these spaces may be inaccessible for persons who use mobility devices if 

• the corridors and doorways are too narrow, or
• thresholds are too high and without adequate bevels (to prevent a person from tripping on or catching their mobility device).

Inaccessible living spaces can make it difficult for persons who use mobility aids to visit friends and family, participate in their community, and indeed live in their own home.

This proposed change introduces new requirements for dwelling units that are designated as visitable by federal, provincial, territorial regulations or municipal bylaws, such that the entrance level is designed to have the following:

• a path of travel with a clear width not less than 1 000 mm,
• doorways with a clear width not less than 850 mm when the door is in the open position, and
• thresholds no greater than 13 mm and beveled in accordance with NBC accessibility requirements.

By introducing minimum clear width requirements for access to all habitable rooms on the entrance level, the proposed change is expected to limit the probability that persons who use mobility aids would be unable to access facilities in the dwelling unit, irrespective of whether they live there or are visiting.

Providing access to habitable rooms on the entrance level is one of the main features of visitable dwelling units [1] and is essential for accessibility. Over 4% of community-dwelling Canadians over the age of 15 regularly use some type of walking aid (e.g., walker, rollator or cane) [2], and 1% regularly use a wheeled mobility aid (e.g., wheelchair or scooter) [3]. However, the prevalence of disabilities related to mobility and the associated use of assistive aids increases with age, with over 18% of community-dwelling Canadians over the age of 75 regularly using canes or walking sticks, 14% regularly using walkers or rollators, and 4% regularly using wheelchairs or scooters [2],[3]. As such, many Canadians will use assistive aids for mobility at some point in their lives and will require larger spaces for access to the washrooms and other essential building facilities while using these devices.

This proposed change should be considered in the context of PCF 1958, which proposes minimum technical requirements for a washroom in a visitable dwelling unit.

This proposed change only applies to dwelling units in multi-unit residential buildings that are required by the federal, provincial, territorial or municipal authority to be designed to be visitable. It does not apply to detached houses, semi-detached houses, houses with a secondary suite, duplexes, triplexes, town houses, row houses or boarding houses.

Costs

Overview

Visitability requirements only apply to dwelling units where mandated by authorities having jurisdiction. In such case, where a federal, provincial or territorial or municipal authority introduces requirements for visitable dwelling units, PCF 1884 would also introduce the following three changes to the entrance level of a visitable dwelling unit, the expected impacts of which are also described below:

1. Increases the minimum width of a corridor in a dwelling unit from 860 mm to 1 000 mm (4% increase in total construction cost per visitable dwelling unit).
2. Requires each doorway to have a clear width of at least 850 mm ($15.31 increase per visitable dwelling unit, which is too small to present as a percentage increase in total construction cost).
3. Sets maximum door threshold height at 13 mm (not expected to present a measurable increase in total construction cost).

1. Calculation of Cost Impact for the Proposed Increase in Minimum Corridor Width

The layout of the dwelling unit could be adjusted to limit the consequences to the available space and thus prevent additional costs.

However, in cases where room sizes or plan elements cannot be changed, the overall dimensions of the dwelling unit may need to be adjusted to comply with the wider corridor and doorway widths required by this proposed change.

• Unit Length: 8 m
• Unit Width: 6 m
• Orientation of Paths of Travel: 1 corridor width wise and another corridor length wise, so the dwelling unit would need to be increased in its length and its width.
• Change in Minimum Width of Path of Travel: 1 000 mm (PCF 1884) − 860 mm (NBC 2020) = 140 mm = 0.14 m

Figure 1. Example applying the proposed change in minimum width of path of travel in a dwelling unit 

Table 1 shows the average cost to construct the example dwelling unit (condo) in Figure 1, based on the Altus Group 2023 Construction Cost data for multi-unit residential buildings (MURBs) in different Canadian regions.

Table 1. Average Construction Cost of a 48 m² Condo 

Notes to Table 1:

(1) GTA = Greater Toronto Area

(2) N/A = not available

(3) Condo only.

Table 2 shows the worst-case scenario cost increase if a designer were to simply increase the length and width of a dwelling unit to be compliant with PCF 1884.

Table 2. Increase in Construction Cost to Expand an 8 m × 6 m Condo by 290 mm in Both Directions

Notes to Table 2:

(1) GTA = Greater Toronto Area

(2) N/A = not available

(3) Condo only.

Calculation of Total Cost of Proposed Corridor Width in the Example Condo

The following calculation may be used:

% Cost Increase due to Increased Minimum Corridor Width = (Increase in Construction Cost listed in Table 2 / Average Construction Cost) × 100 = 4%

% Cost Increase due to Increased Minimum Corridor Width = 4%

* The cost increase described above is only applicable in the following cases:

• Where a designer ensures compliance by increasing the size of the dwelling unit instead of revising the layout of the home.
• For a dwelling unit having the dimensions used in the example. It should also be noted that smaller units could see a greater percentage increase in construction costs, while larger units could see a smaller percentage increase in construction costs.

2. Calculation of Cost Impact of the Proposed Clear Width for Doorways

Some of the cost of increasing the minimum door width is offset where a wider door reduces the amount of interior wall that needs to be constructed. The impact of increasing the minimum door width is calculated as follows:

• Most dwelling units in new-build MURBs have open-concept designs so they do not have doorways at the entrance of living rooms or kitchens; in this case, only washroom doorways would need to comply with the proposed clear width requirement.
• A dwelling unit in a MURB will only have one washroom that needs to be visitable.
• The NBC 2020 Part 9 minimum door width requirement for washrooms (610 mm) can be converted into a minimum clear width requirement that is calculated by subtracting 50 mm (i.e., 44 mm + 6 mm = interior door thickness + interior door jamb stop width) from the minimum door width. This means the NBC indirectly requires an approximate minimum clear width of 560 mm for doorways at washroom entrances.

Cost of Increased Door Width

Since PCF 1884 proposes a minimum clear width of 850 mm at entrances to washrooms, this would require a 900 mm door width (i.e., 850 mm + 50 mm = minimum clear width + assumed conversion adjustment). Table 3 identifies the cost difference between a 610 mm wide door and a 900 mm wide door.

Table 3. Comparison of Cost of Different Door Widths across Canada 

* The difference in cost between the RSMeans Birch Hollow Core doors (610 mm versus 900 mm) represents the largest cost difference, so $49 is the assumed cost increase associated with the new minimum clear width requirement.

Cost Reduction due to Constructing Less Wall

Since one of the assumptions made was that the NBC 2020 indirectly requires a minimum clear width of 560 mm at the entrance to washrooms, and PCF 1884 proposed to increase this to 850 mm, there is a 290 mm reduction in interior wall construction. Table 4 shows the RSMeans costing per metre for standard interior wall construction.

Table 4. Pricing a Basic Interior Wall

* Reduction in required length of interior wall × Cost of interior wall per length

= 0.29 m × $116.18/m

= $33.69, which is the assumed cost decrease associated with building less interior wall because of the wider door being installed.

Total Cost of Proposed Clear Width for Doorways

= Cost of increased door width − Cost reduction due to constructing less wall 

=$49.00 − $33.69

= $15.31

Benefits

The proposed change is expected to improve accessibility in dwelling units, both for the persons who reside there and for their visitors. Approximately 10% of Canadians have a disability related to mobility [4] and 4% of Canadians in the community regularly use some form of walking aid [2]. However, the prevalence of the use of disability and mobility aids increases with age, with over 18% of community-dwelling Canadians over the age of 75 regularly using canes or walking sticks, 14% regularly using walkers or rollators, and 4% regularly using wheelchairs or scooters [2],[3]. As such, many Canadians will use assistive aids for mobility at some point in their lives, highlighting the need for housing that is designed for access while using mobility aids.

Social isolation and loneliness are common in older adults and are severe risk factors for poor health and mortality. A recent literature review in Canada reported that the risk is comparable to smoking, alcohol consumption, obesity or frailty [5]. Strategies to promote social interaction and reduce isolation are urgently needed to enable people to live in the community for as long as possible. Promoting visits to the home, whether through a program or informally with friends and family, is one of the established strategies for reducing social isolation and loneliness [6]. Designing dwelling units so that residents and visitors can access normally occupied spaces on the main floor would help to support these social interactions that forestall loneliness and isolation as well as their associated health consequences.

References

(1) Canadian Centre on Disability Studies, via the Canadian Mortgage and Housing Corporation. (2017). Barriers and enablers to the uptake of VisitAble housing in Canada: Stakeholder perceptions. Retrieved March 8, 2023 from: https://eppdscrmssa01.blob.core.windows.net/cmhcprodcontainer/sf/project/archive/research_2/barriers_and_enablers_jul5_corrected.pdf

(2) Charette, C., Best, K.L., Smith, E. M., Miller, W.C., and Routhier, F. (2018). Walking aid use in Canada: prevalence and demographic characteristics among community-dwelling users. Physical therapy, 98(7), 571–577.

(3) Smith, E.M., Giesbrecht, E.M., Mortenson, W.B., and Miller, W.C. (2016). Prevalence of wheelchair and scooter use among community-dwelling Canadians. Physical therapy, 96(8), 1135–1142.

(4) Statistics Canada, "A profile of Canadians with a mobility disability and groups designated as visible minorities with a disability". (2020). Retrieved October 30, 2023 from https://www150.statcan.gc.ca/n1/daily-quotidien/201203/dq201203a-eng.htm)

(5) Freedman, A., and Nicolle, J. (2020). Social isolation and loneliness: The new geriatric giants: Approach for primary care. Canadian Family Physician, 66(3), 176-182.

(6) Dickens, A.P., Richards, S.H., Greaves, C.J., and Campbell, J.L. (2011). Interventions targeting social isolation in older people: a systematic review. BMC public health, 11(1), 1-22.

This proposed change could be enforced with simple measuring tools (e.g., tape measure), similar to those used to enforce barrier-free paths of travel in public spaces.

Authorities having jurisdiction would need to be aware of this proposed change and its application to visitable dwelling units.

Builders, architects and engineers would need to consider wider doorways and hallways in their plan layouts. 

Regulators would need to ensure that dwelling units designated as visitable comply with the new requirements.

Building occupants who use mobility aids would be able to navigate key spaces (e.g., kitchen or living room) within dwelling units, irrespective of whether they live there or are visiting friends and family.