Design ABC

1. Introduction
An accessible or inclusive environment is one that can be used by everyone, regardless of age, gender, ethnicity or disability. An accessible environment is built on the principles of Inclusive or Universal Design. Although universal design also applies for the design of products, information, communication and policy to be usable by a range of people operating in the widest range of situations without special or separate design, in our section on accessible environments we have provided general information only on built environments.

2. Concept of Good Design
A good design should enable every one including persons with reduced mobility to:
  1. Reach all places
  2. Enter all places
  3. Use all facilities
a profile photo of Mr. Ronald Mace -man with a grey beard sitting on a wheelchair
Mr. Ronald Mace - Father of
Universal Design (1941-1998)
3. Universal Design
Universal design is the design of products and environments to be usable by all people, to the greatest extent possible, without the need for adaptation or specialised design.  - Ronald Mace
Universal design is a philosophy of design that recognises, and attempts to accommodate the broadest possible spectrum of human ability in the design of all products and environments.

It requires sensitivity to, and knowledge about people of all ages and abilities. Sometimes referred to as "lifespan design" or "trans-generational design", it encompasses and goes beyond the accessible, adaptable, and barrier-free design concepts of the past.

Universal design helps eliminate the need for special features and spaces for "special people" (for example, people with disabilities) which are often different-looking, more expensive and can be stigmatising.

Universal design is about ability, rather than disability. It encompasses designs for the full human life cycle, from beginning to end.

4. The 7 Principles of Universal Design
  1. Equitable Use: The design does not disadvantage or stigmatise any group of users.
  2. Flexibility in Use: The design accommodates a wide range of individual preferences and abilities
  3. Simple, Intuitive Use: Use of the design is easy to understand, regardless of the user's experience, knowledge, language skills, or current concentration level.
  4. Perceptible Information: The design communicates necessary information effectively to the user, regardless of ambient conditions or the user's sensory abilities.
  5. Tolerance for Error: The design minimises hazards and the adverse consequences of accidental or unintended actions.
  6. Low Physical Effort: The design can be used efficiently and comfortably, and with a minimum of fatigue.
  7. Size and Space for Approach & Use: Appropriate size and space is provided for approach, reach, manipulation, and use, regardless of the user's body size, posture, or mobility.
5. UDIP (Universal Design India Principals) by National Institute of Design
i. The UDI principles are stand alone universal design ideologies that  focus in Indianness and inclusivity as they relate to age, gender, disability, caste, class, religion, poverty and urban/rural background.
ii. UDI principles neither make any connection nor build on the 7 Universal Design Principles. They recognise the overarching importance of the 7 Principles in the field of universal design.]

Principles, Description and Guidelines (in Indian context):

5a. Equitable/ Saman (समान) : The design is fair and non-discriminating to diverse users.
-Avoid prejudices against people of all ages, gender, disability, sizes, caste, class & religion.
-Consider different capabilities of users and build in many levels of engagement.
-Provide choices in access and use thru flexibility and customisation.
-Allow personalisation through inclusion of adjustable and adaptable options.
-Provide equality in challenge, opportunity and energy requirement.

5b.  Usable/ Sahaj (सहज) : The design is operable by all users.
-Provide independence, comfort, safety and support during use.
-Facilitate access, operation and convenience by diverse users.
-Include adaptations for those experiencing difficulty in use.
-Provide clarity in use, operation, maintenance to minimise instruction to avoid confusion and error.
-Adopt simple means to overcome complex operation.
-Follow cultural norms to address user expectations.
-Offer multi-sensory feedback to point in the right direction. 
-Build in intuitive operation and innate understanding of problem.
-Allow easy adaptation to facilitate use by people with diverse abilities.
-Prevent costly mistakes and untended consequence from misuse.

5c. Cultural / Sanskritik (सांस्कृतिक) : The design respects the cultural past & the changing present assist all users.
-Maintain social and traditional qualities in design.
-Include Indian idioms to make historic and social connection.
-Present in many languages for inclusive comprehension.
-For all castes and society levels.
-Respond to local context and conditions.
-Employ appropriate technology to match user expectations.

5d.  Economy/ Sasta (सस्ता) : The design respects affordability and cost considerations for diverse users.
-Ensure affordability, durability and maintainability.
-Use local materials for energy savings and cost effectiveness.
-Focus on low unit cost through wide distribution.
-Adopt modular approach to offer choice in features and price range.

5e. Aesthetics/ Sundar (सुंदर) : The design employs aesthetic to promote social integration among users. 
-Employ aesthetic to enhance universal appeal and use.
-Allow personalising aesthetics through flexibility, adaptability and modularity of colour, form, texture and interaction.
-Employ appearance to inform use and safety.
-Bridge wide range of meaning and comprehension gaps.

6. Accessible
Accessible means that disabled persons can, without assistance, approach, enter, pass to and from, and make use of a built environment without undue difficulties. Providing easy access into and around buildings and public spaces is important for everybody but essential for disabled people.
7. Space Allowance
Adequate space for persons using mobility devices. Adequate space should be allocated for persons using mobility devices, e.g. White Canes, Wheelchairs, Crutches and Walkers, Electric Wheel Chairs as well as those walking with the assistance of other persons/escort animals. The range of reach (toward and side; with or without obstruction) of a person in a wheelchair should be taken into consideration. Attention should be given to dimensions of mobility devices used locally.

8. Ramps
  • A ramp should be of gentle gradient, with a landing maximum every 6 meters.
  • The ramp width should be min. 1200 mm clear and preferably 1500 mm for one way movement and 1800 mm- 2000 mm for two ways movement.
  • A ramped approach should have handrails continuously on both sides, and raised kerbs on open edges.
  • Handrails attached to ramps should be of at correct height which enables wheelchair users and crutch users to hold easily, 
  • Handrails should extend horizontally beyond the top and bottom of the ramp. (min. 300 mm).
  • Ramp and landing surfaces should be slip-resistant.
  • For handrails refer Section on "Handrails/Grab Bars".
  • Ramps and landing surfaces should comply with the guidelines for "Ground and Floor Surfaces"
9. Kerb Ramps
  • Kerb ramps should be provided wherever an accessible route crosses a step or kerb.
  • Slopes of kerb ramps should be gentle (e.g: less than 1:10).
  • The surface of kerb ramps should comply with the guidelines for "Ground and Floor Surfaces".
10. Pathways and Corridors
  • Pathways and corridors should be wide enough for wheelchair users. 
  • If a corridor is less than 1500 mm.(minimum clear turning space), turning space should be located at reasonable intervals.
  • The surface of pathways or corridors should comply with the guidelines for "Ground and Floor Surfaces".
  • Space for headroom and protruding objects should comply with the guidelines for "Protruding Objects".
11. Steps and Stairs
  • A flight of stairs should have uniform risers (150mm) and treads (300mm).
  • A flight of stair should be of gentle gradient.
  • A flight of stairs should have no open risers.
  • Nosing of stairs should project as little as possible.
  • Handrails for stairs should be installed on both sides and continuously.
  • Handrails for stairs should be easily gripped at a suitable height from the stair run.
  • Handrails for stair should extend beyond the top and bottom of the stairs horizontally to 300 mm.
  • Stair edges should be in bright contrasting colours.
  • Stairs should be adequately illuminated (150 Lux).
12. Doorways
  • Doorways should be wide enough for wheelchair users (minimum clear width of 900 mm).
  • Space to manoeuvre should be provided in front of doors, including sufficient space for moving past door handles.
  • Thresholds of doorways should not exceed 10 mm. Raised threshold and floor level changes at doorways should be leveled off with a slope on each side of a threshold. The slope may be a simple, movable ramp.
  • Handles, pulls and others opening devices are to have a shape and height that is easy for a person with reduced strength and dexterity to control.
  • Swing door is preferable than a sliding door. When a sliding door is to be used, the handle should be usable from both sides.
  • Lever handles and push type mechanisms are recommended. 
  • The use of colour to distinguish doors from surrounding walls is very useful for people with visual impairments.
  • Glass doors must have a bright, coloured motif at eye level or a manifestation at two levels for users of different heights (viz. sitting and standing adults).
  • Where revolving doors or turnstiles are unavoidable, an alternative wheelchair-accessible entrance must also be provided.
13. Windows
  • A window should have handles/controls at a height permits use from wheelchairs.
  • A window should have an unobstructed viewing zone for wheelchair users.
  • Curtain or venetian blind controls/ropes should be accessible for wheelchair users.
14. Handrails and Grab Bars
  • A handrail or grab bar should be of a diameter/width and strength so that it may easily be grabbed and used as a support.
  • If handrails or grab bars are mounted adjacent to a wall, clearance space between the walls and the grab bar should be provided.
  • Handrails should have continuous gripping surfaces, without interruptions or obstructions that can break a hand hold.
  • If handrails or grab bars are mounted in a recess, the maximum depth and minimum height of the recess must be considered.
  • A small braille plate/sign should be provided at the beginning and at the end of each handrail/grab bar to indicate its position to persons with visual impairments.
  • Handrails/grab bars should be in a colour that contrasts with the surrounding area.
  • Grab bars should be installed to resist a force of at least 1.3 kn applied vertically or horizontally.
15. Ground and Floor Surface
  • Ground and floor surface (along accessible route and in accessible rooms spaces, including floors, walks, ramps, stairs and kerb ramps) should be stable, firm and slip-resistant.
  • Floor surfaces should not have any projections, drops or unexpected variation in levels.Changes in level less than and 12mm should be beveled with a slope no greater than 1:2.
  • Grating located along walking surfaces shall:
    • have spaces not greater than 12 mm wide in one direction, and
    • be placed so that the long dimension is across the dominant direction of travel.
  • If carpets or carpet tiles are used on a floor surface, they should be securely attached to it. Long, thick rugs should not be laid in areas likely to be frequented by persons with mobility and sight impairments.
  • Edges of paths should be clearly defined by using different colours and textures. Street furniture, trees, lighting and dustbins should be located on one side of pathways. The surface texture and colour surrounding should be changed to indicate the approach to those items.
16. Tactile Ground Surface Indicators (TGSI) for Blind/ Visually Impaired Users
  • Tactile Ground Surface Indicators (TGSIs), also known as tactile pavers, provide a distinctive surface pattern of “strips” and "truncated domes" or cones (which are small domes or cones that have had their tops cut off, or truncated) detectable by long cane or underfoot which are used to guide/alert persons with vision impairments of their approach to facilities, streets, and hazardous drop-offs.  People who are blind or visually impaired are alerted of impending danger from vehicle impact or a grade change. 
  • TGSI come in the size of 300mm x 300mm patterns / tiles / rubberised stick-ons can also be arranged in this size while placing it on the ground. One or more rows could be used depending on usage. 
Image of two types of TGSI as per the Harmonized Guidelines 2021

  • Tactile Warning Indicators (Dottype)/ Tactile Warning Blocks- Warning indicators, as the name suggests, warn of either a hazard or a destination. For example, a warning indicator near the edge of a staircase landing warns of the edge of the landing, which which, otherwise, would pose a significant hazard to a pedestrian with low vision. As the person approaches the edge, the tactile warning treatment will be identified either by the white cane or underfoot, thus warning of an impending drop to the staircase. 
  • Tactile Guiding Indicators (Linetype)/ Tactile Guiding Blocks- Tactile guiding or directional indicators are used to direct the user from one point to another along a safe path of travel. They are only required when there are insufficient cues from other sources to achieve the same result. 
  • Tactile paving should be used on access routes to provide warning and guidance to people with visual difficulties. The need for TGSI’s is critical and requires to be laid out with a holistic integration with built environments. Partial and incorrect laying of TGSI’s may cause inconvenience and may be hazardous for persons with visual impairments. TGSI’s should be well integrated and appropriately placed into external and internal spaces right from the inception stage of a built environment. It is recommended to make TGSI’s part of the access route plan.
  • TGSIs have a specific function and impart specific information about the immediate surroundings. TGSIs act as, and are interpreted as landmarks. The two types of Tactile pavers that we use in India are warning indicators and directional indicators.
  • Places to install TGSI for persons with impaired vision :-
    • To indicate level change or direction change.
    • In front of an area where traffic is present
    • In front of an entrance/exit to and from a staircase or multi-level crossing facility.
    • Entrance / exits at public transport terminals or boarding areas.
    • Sidewalk section of an approach road to a building.
    • Guiding path from a public facility to the nearest public transport station.
  • TGSI (guidine pattern) are not required to be provided on ramps or stairs. Only TGSI (warning pattern) are needed 300mm before and after the ramp/stair run.
  • Rural Areas: In rural areas, tactile orientation using stones of different sizes to seperate the road from the kerb and to indicate approah to public places can be used as the tiles may be impractical.
17. Lighting
  • Adequate and well distributed lighting should be installed.
  • Glare from excessively bright lights should be avoided.
  • Circulation spaces should have adequate lighting.
  • Lighting of 150 Lux in corridors, stairs, ramps etc is recommended whereas on a study table or a kitchen, a lighting of 300-500 Lux is recommended.
18. Signage
  • Signage should be in contrasting colours (70%) in distinct relief (raised) to allow visually impaired persons to obtain the information by touch.
  • Simple symbols and contrasting colours which are universally recognised should be used, e.g. green for safety or go, yellow or amber for risk or caution, and red for danger.
  • Use system of signs throughout a building. Directional signs should be placed at location along the route to designated areas.
  • The height of signs should comply with the guidelines for "Protruding Objects".
19. Elevators
  • The floor space of lifts should be sufficient for wheelchair users to enter the lifts, manoeuvre within reach of controls, and exit.
  • Lift doors should be wide enough for wheelchair users.
  • Lift door closing mechanisms should be adjustable to give adequate entry time for people with disabilities. The installation of photo-electric sensor may be considered for controlling the closing of the lift door.
  • In lift lobbies, access and manoeuvring space for wheelchair users should be provided.
  • Call buttons in lift lobbies should be at a height that is within easy reach of and for use by wheelchair users.
  • All control buttons should include Braille, have raised numbers and have symbols to indicate "Open" and "Close".
  • A voice indicator should be to installed to announce floor levels.
  • Lift floor should always be level with the lift lobby floor.
  • Where it is impracticable to provide a lift or ramp, a wheelchair stair lift or platform lift may be considered as alternative.
20. Toilets
  • Accessible public toilets should be identified by international signage of accessibility (Wheelchair symbol facing right) on the wall between 1200-1600mm height from the floor towards the latch side of the door.
  • WC or toilet compartments should have enough floor space for wheelchair users to enter and exit & transfer on to the WC.
  • The toilet bowl should be of a type (e.g. wall hung) and in a position as to permit easy approach by wheelchair users.
  • The seat of the toilet bowl should be at the correct height for the wheelchair users. Any accessory seat pad on the toilet seat should be firmly secured.
  • WC compartments should have grab bars/ support rails at a position and height suitable for wheelchair users and other persons with physical disabilities. Upward-folding support bars are recommended to allow lateral transfer from the wheelchair.
  • A toilet paper dispenser should be so installed as to be easily used by a person with physical impairments sitting on the WC.
  • Fittings, such as soap dispenser, electric hand dryer and mirror, should be low enough for a wheelchair user to use comfortably.
  • Floor finishes should be of non-slip material. Doors should be either of the sliding or outward-opening type and provide clear opening of 900 mm.
  • Locks to toilet doors or cubicle should be a type that can be opened from outside in case of emergency. Lock lever should be of the type that can be easily opened by person with weak grip power.
21. Wash Basins
  • The basin should be installed at a height and position for convenient access by wheelchair users.
  • The basin should have appropriate knee clearance and foot clearance space for wheelchair users.
  • Sufficient clear space for wheelchair users should be provided in front or the basin.
  • The mirror should be so installed as to permit its use by wheelchair users.
  • Lever-type taps should be installed to wash basins.
22. Bath Rooms
  • Shower cubicles should have seats with width and height to facilitate easy transfer by wheelchair users.
  • Shower cubicles should have grab rails at a height and position that allow for easy gripping by wheelchair users.
  • Shower cubicles should have call buttons or other signal devices at a height and position easily reached in an emergency.
  • Sufficient space should be provided beside shower cubicles for transfer by wheelchair users.
  • Shower doors, locks or catches should be of a type that can be opened from the outside in an emergency. Lock lever should be of the type that can be easily open by person with weak power.
  • Shower door should preferably be outward opening type.
  • Towel rail to be placed within reach of person sitting on shower seat at 1200-1300 mm height.
23. Bed Rooms
  • The space around the bed should be adequate for access by wheelchair users.
  • The space around the bed should be large enough for transfer by a wheelchair user, or for a helper to assist in the transfer.
  • The bed should be at a height from the ground that permits wheelchair users to transfer easily.
  • There should be bed-side table at a suitable height and position that permits a person lying on the bed to reach it easily.
24. Kitchens
  • Floor surfaces should be of a slip-resistant material.
  • Worktops, sinks and cooking hobs should beat the same level and a height suitable to wheelchair users.
  • Adequate knee room should be provided beneath worktops and sink.
  • Floor space should allow easy wheelchair movement between worktop, sink and cooking stove.
  • Taps preferably should be of the mixer type, with lever handles.
  • Where cooking facilities have control taps or knobs, these should be installed at the front of the appliance and be easily and safely operated by people with diverse disabilities.
  • Where appropriate, oven doors should hinge downwards.
  • Where solid fuel stoves are used, the needs of people using wheelchairs or crutches and blind people should be considered in designing for adequate operating space and safety.
  • Sufficient lighting levels must be maintained in the kitchen area.
25. Parking Space
  • Accessible parking spaces should be located on the shortest accessible route into a building or facility, and should be roofed wherever possible.
  • Parking areas should have enough clear space around them so that disabled persons can get into and out of a car.
  • Reserved parking spaces for vehicles carrying persons with disabilities should be provided, indicated by the international sign of accessibility.
  • Access route from parking lots to the building should be accessible by wheel chair users.
26. Storage Space
  • Storage space of various kinds (shelves, wardrobe rails, cupboards and drawers) should be appropriate height and depth reachable by people in wheelchairs.
  • A recessed space should be provided under storage units to accommodate the footrests of a wheelchair.
  • Cupboard and drawer handles should be a shape which may be easily grasped by a person with limited gripping or pulling strength.
  • Lockable drawers should be provided for each occupant in residential institutions.
  • A refrigerator should be at a suitable height and depth for easy reach by wheelchair users.
  • Sufficient floor space should be provided for wheelchair users to maneuver around open doors of cupboards and refrigerators.
27. Tables
  • A space should be provided for wheelchair users at tables.
  • A space should be provided for wheelchair user access to and from tables.
28. Protruding Objects
  • Protruding objects, such as directional signs, tree branches, wires, guy ropes, public telephone booths, benches and ornamental fixtures should installed with consideration of the range of a visually impaired person's cane. (detection area) (Eg. detectable objects such as planter box, refuse bin and warning surfaces).
  • A barrier to warn blind or visually impaired persons shall be provided under stairways or escalators.
  • Walkways, halls, corridors, passageways, aisles, or other circulation space should have clear head room to minimize the risk of accidents. (Eg. overhanging obstruction)
29. Wheelchair Seating
  • Applies to wheelchair spaces in gallery like auditorium, assembly halls, theaters, sport centers and similar facilities.
  • Accessible seating space should be provided in a variety of locations to give persons with physical disabilities a choice of admission prices. Seating area must be installed at position allowing ease of evacuation.
  • Wheelchair spaces to be allocated the ratio of 2 for every 100 seats with the minimum of 1 seat for any smaller number of total seats. Additionally there should be sufficient foldable seats so as to make space for a group of wheelchair users.
  • For hearing impaired person, a hearing aid broadcast system such as a magnetic loop or an FM transmitter/receiver / induction loop may be installed.
30. Switches and Outlets
Switches and outlets should be mounted at an appropriate height and position for easy reach & use by wheelchair users.

31. Communications Systems 
      31 a. Public Telephone
  • Sufficient floor or ground space for a forward or parallel approach by a wheelchair user should be provided near telephone booths.
  • Cubicle doors and fixed seats should not block approaches to and from telephones for people who use wheelchairs. As an alternative to fixed seats, folding seats may be provided in telephone booths.
  • The highest part of a telephone should be within reach of a seated person.
  • Knee space should be provided under telephones.
  • Telephones should have push button controls.
  • A long cord from the telephone to the handset should be provided.
  • It is highly recommended that telephones have "hands-free" receivers.
      31 b. Telecommunication Devices for Deaf Persons (TDD)
  • Telecommunications devices for deaf persons (TDD) should be installed adjacent to pay-phone booths.
  • TDD should be identified by the "TDD" symbol.
  • Pay-phones should be hearing-aid compatible.
  • Pay-phones should be have volume controls.
  • Visual Notification Devices should be provided in offices, workplaces, hotel rooms and homes to alert hearing-impaired persons to in-coming telephone calls.
      31 c. Assistive Listening Devices
  • Assembly areas, as well as conference and meeting rooms should provide assistive listening devices for persons with hearing impairments.
  • Various types of assistive listening systems are available on the market. They include audio-induction loops, radio frequency systems and infrared transmission devices.
  • Assistive listening devices should be available for use in:
    • Theatres, concert halls, auditoriums, stadiums and other places of cultural activity;
    • Museums, galleries and other places for public display;
    • Zoos and amusement parks.
      31 d. Sign Language Interpretation
Adequate lighting, raised platforms and headphone sets should be provided for sign language interpreters.
      31 e. Braille
  • Braille symbols and/or text in raised format should be provided in places frequented by persons with visual impairments.
  • Text/symbols and the background of all signs should have a non-glare finish. They need to be in sharp contrast to their background.
  • "Talking signs" should be installed.
32. Emergency Warning & Evacuation System
  • It concerns vocal alarms, vibrating alarms and instructions for escape from danger.
  • If emergency warning systems, e.g. vibrating alarms or vocal alarms, are installed, they should include a means of warning for visually impaired persons.
  • Visual alarm devices should be provided for persons with hearing impairments.
  • Sockets should be provided near beds to allow alarm systems, including vibrating under-pillow devices, to be connected easily.
  • Buildings should identify "areas of rescue assistance".
  • Fire man's lifts must also be accessible for people with disabilities.
  • Emergency evacuation plans identifying responsibilities of staff must be notified.