Universal design vs accessible design

Two ideas that overlap

Accessible design focuses on removing barriers for people with disabilities. It usually means meeting a defined standard with measurable requirements, such as clear floor space, door widths, grab bars or colour contrast. In Canada, a key national reference for the built environment is CSA B651, Accessible design for the built environment.

Universal design starts from a broader question: how do we design for the widest possible range of people from the start, so that adaptations or special features aren't needed later? The idea is closely linked to architect Ron Mace and the Center for Universal Design at North Carolina State University.

The two aren't opposites. Accessible design sets a dependable floor for specific needs. Universal design shapes the whole space so it works for more people, including children, older adults, parents with strollers and people recovering from an injury, as well as people with disabilities.

The seven principles of universal design

In 1997, a working group of architects, product designers, engineers and environmental design researchers at NC State, led by Ron Mace, published seven principles of universal design. Here are their names, with our plain-language summary and a housing example for each.

1. Equitable use. The design is useful to people with diverse abilities, without singling anyone out. Example: one main entrance everyone can use, instead of a separate side ramp.
2. Flexibility in use. It suits a range of preferences and abilities. Example: closet rods and shelves that adjust in height.
3. Simple and intuitive use. It's easy to understand, whatever someone's experience, language or concentration. Example: an elevator you can see as soon as you enter the lobby.
4. Perceptible information. It communicates what people need to know, whatever their senses. Example: elevator buttons with raised characters and braille, plus spoken floor announcements.
5. Tolerance for error. It reduces hazards and the consequences of mistakes. Example: anti-scald valves on taps and showers.
6. Low physical effort. It can be used comfortably, with little effort. Example: lever handles and large rocker light switches.
7. Size and space for approach and use. There's room to reach and use things, whatever someone's body size, posture or mobility. Example: clear space beside the bed and in front of appliances.

The full principles and their guidelines, Version 2.0, are copyright NC State University, The Center for Universal Design (1997). They're linked in the sources below.

Where CSA B651 fits

CSA/ASC B651:23 is the 2023 edition of the National Standard of Canada for accessible design for the built environment. It sets minimum technical requirements so that buildings and spaces can be used by people with a range of physical, sensory and cognitive disabilities.

B651 is an accessible design standard. It tells you what a space must provide, with measurable criteria a designer can show on drawings and a reviewer can check on site. That precision is its strength.

Universal design rarely comes with that kind of checklist. It's a set of principles, so two teams can apply it in different ways. That flexibility is useful, but it means you need to document your choices clearly.

In Ontario, the Building Code sets the legal accessibility requirements for most buildings. Some programs, including MLI Select, point to CSA B651 directly.

Accessible and universal design units in MLI Select

CMHC's MLI Select program uses both ideas. As of October 2026, every project claiming accessibility points must first make all units 100% visitable and all common areas barrier-free, under CSA B651:23. Then:

• Accessible units are units that meet CSA B651:23.
• Universal design units are tied to the principles of universal design.

CMHC's MLI Select page doesn't define a universal design unit in detail. Its required documentation guide asks for a summary of key accessibility and universal design features and a sample unit design, and an architect or designated accessibility consultant signs an attestation. In practice, the project team needs to decide, document and be ready to explain how its universal design units apply the principles.

Level 1 (20 points) can be met with at least 15% accessible units or at least 15% universal design units. Level 2 (30 points) options include 15% accessible units plus 85% universal design units, or 100% universal design units. Our MLI Select explainer covers every pathway, including RHFAC.

Putting them together

The strongest projects use both. Universal design makes every unit and shared space easier to use, and accessible units meet the specific, measurable needs of residents who rely on them. Many universal design choices, such as wider doors, step-free routes and reinforced walls, can also make it simpler to adapt a unit later.

• Decide early which MLI Select pathway, if any, you're aiming for
• Treat visitability and barrier-free common areas as the starting line
• Write down how each universal design feature responds to the principles
• Involve people with disabilities in reviewing plans and model units
• Keep the design and the attestation in step as drawings change

Sources

• CMHC: MLI Select
• CMHC: MLI Select required documentation guide (PDF)
• CMHC: MLI Select accessibility criteria attestation (PDF)
• CSA Group: CSA/ASC B651:23, Accessible design for the built environment
• Centre for Excellence in Universal Design (National Disability Authority, Ireland): The 7 principles
• Government of Ontario: Accessibility in Ontario, what you need to know