7 SPECIAL CONSIDERATIONS IN DESIGN INTERIORS

M.R. Thilagam

SPECIAL CONSIDERATIONS IN DESIGN INTERIORS

Designing for people with special needs and design that deals ethically with the environment is more crucial than designing for normal occasion.. For years the needs of special groups of people, who found designed environments difficult or even impossible to use, were often ignored by designers. Today, however, because we have been made aware of special needs, and because the law requires that those needs be addressed, design for special populations is .a standard part of design practice. An awareness of the importance of caring for the fragile environment that sustains life has also had a significant impact on the practice of design.

The main objectives of this lesson today is

1. To gain knowledge on special considerations for designing life space for people with special needs.

2. To understand design longevity and environment.

3. To know the importance of energy conservation.

Who is a Special Population

People with distinctive but similar design needs constitute special populations. Such populations include persons with limited motion, hearing, or vision, as well as the elderly who may have some form of impairment in one or more of these areas. It is important to note that impairments need not be measured by fixed standards and that every one of us is prone to some type of limitation, whether temporary or chronic. The designation of “special populations” is helpful only because it makes us aware of needs.

Different kinds of physical impairments may require conflicting considerations. For example, curbs that are cut away for the wheelchair-bound do not signal the blind that they have reached the street. The person in the wheelchair prefers spaces that are open and larger than normal, while the blind person is more comfortable in a smaller space where many things are within reach. The hearing impaired needs a space with little sound reverberation, while the blind need an acoustically “live” space to help them find their way.

Universal Design

Universal design implies that well-planned designs will meet the needs of every user without drawing attention to persons with disabilities. For example, older buildings with many steps are not accessible to regular wheel chair users. Ramps can be installed to make the building accessible. But the ramp is a special addition, and while it is functional, it draws attention to the wheelchair user, who must use a different method of entry. New facilities designed on level grade, where all can enter in the same manner, are examples of universal design—everyone accommodated without drawing attention to distinction of ability.

Accessible Design

Accessibility is the law in nonresidential design. It is optional in design for single-family homes. Given the fact, however, that we may all encounter some form of impairment at some point in our lives, it is remarkable that our home designs rarely are planned accordingly. Some have the foresight and plan for their family members at some point of their lives. However universal design works well for every one whether impaired or not.

Design for Motion Impairments

People with impaired motion may be ambulant-disabled, meaning that difficulty in walking may require the use of crutches, a cane, or a walker. The chair bound-disabled depend on a wheelchair for mobility. The motion-impaired may also have some loss of ability to use their hands. This section will cover lists of design recommendations for people with motion impairment.

Steps and Ramps

A minimum slope for ramps • is best, with a rise of 1 foot for-every 12 feet of length (1:12).
Steps should not have protruding nosing which will catch the toes of those with stiff legs, braces, or other leg problems.
All ramps and steps should be well lit, with focus lighting
At the top a handrail should be 34 to 38 inches above the ramp or steps.
Handrails should be oval or round, with 11/2-inch hand clearance between the rails and the wall.
The handrail should have a gripping surface of 1¼ to 1½ inches and should not be interrupted by newel posts or other elements.

Passage and Turning

For a single wheelchair, 32 inches is minimum clearance at a point such as a door (36 inches is better), and 36 inches is minimum clearance in a continuous passage (42 to 48 inches is better). Minimum clearance for two chairs to pass each other is 60 inches.
The space required by a wheelchair to make a 180-degree turn is a clear space of 60 inches.
The clear floor space required for a wheelchair is 30 by 48 inches.
The force needed to push a door open should not exceed 8 pounds of pressure.
Lever-type door handles are easier to operate than round doorknobs, which are slippery and hard to operate with limited strength.
A kick plate at the bottom of a door protects the door from the impact of a wheelchair’s footrest.
Floors should have a flat, nonskid surface. If carpet is used, then it should be securely attached, without a cushion or pad. Pile depth should not be more than ½ inch
Flooring materials should be flushed, since a change in depth greater than ‘1/2 inch forms a barrier.

Kitchens

All areas of a kitchen should be accessible to a frontal approach as well as a parallel approach by a wheel-chair.

Varying countertop heights are recommended. A low counter near the sink for food preparation is helpful. Heights of 28, 32, and 36 inches are good, with a maximum depth of 24 inches so that items on the counter-top can be easily reached.
Upper cabinets should be adjustable to several heights. Eight inches above the counter is the minimum for very small users.
Handles on upper cabinets should be mounted at maximum height of 48 inches: from the floor, with those on lower cabinets a minimum of 27 inches from the floor.
Leaving space under the counter, especially at the sink, allows a wheelchair to approach. The sink controls should be mounted on the side or not more than 18 inches from the front of the counter for easy reach
Pull-out trays allow better access than standard drawer and shelves. Wall-mounted ovens and microwaves allow wheel-chair access.
Cook tops should have staggered burners so that the users do not have to reach over a hot front burner to access a back burner.
Cook top controls should be front mounted for easy reach by a seated person.

Bathrooms

Doors should be at least 36 inches wide (preferably 39 inches). No cabinet under the sink makes the vanity accessible.
Toilets should be wall mounted 19 inches off the floor for easy approach by a wheelchair.
Grab bars must be anchored in wood so that they will support at least 100 kg.
Textured, nonslip grab bars mounted 32 to 38 inches above the floor make access easier. A seat in a shower is also helpful.
Shower controls should be mounted no higher than 32 inches from the floor and should be a lever-type, single-mixing control.
Faucets at the sink should also be lever controlled as well as side mounted.
Medicine cabinets should be mounted lower in a side wall so that they can be easily accessed.
Vanity mirrors should be installed low enough to be used by someone seated in a wheelchair.
Nonslip flooring is imperative, as is good ventilation to prevent condensation that might cause slipping.

Bedrooms

The height of the mattress should be equal to that height of the wheelchair.
To accommodate a wheelchair, there must be a clear space of 60 inches, usually between the bedroom door and the bed, or between the storage space and the bed. A minimum of 36 inches at the foot and far side of the bed will facilitate making the bed and cleaning.

Closets

Bi fold or sliding doors are the best.
Rods should be mounted 45 to 54 inches access from a wheelchair.
Shelves higher than 50 inches arc not accessible from a seated position.
Slide-out shelves are more accessible.

Around the House

Electrical outlets should be 27 to 28inches above the floor. Switches should be 36 inches, above the floor.
At least one 60-inches-diameter turning space is required in each room of the house
Drawer pulls throughout the house should be D-shaped for better gripping.
Window sills set at a maximum of 36 inches make windows accessible to wheelchair users.

Design for Hearing Impairment

Design can help to make the quality of their lives better by alleviating some of the problems inherent in the interior environment. Many of the problems associated with hearing loss center around noise and sound reverberation, as well as adequate light for manual Communication (signing and lip reading).

Things to consider:

Carpet and fabric wall coverings reduce noise reverberation and improve the acoustics for the hearing impaired.
Good lighting is imperative for adequate decoding of manual communication and lip reading.
Good natural light helps visually and also creates the psychological feeling of openness and well-being.
Furniture arranged in a semicircle or U-shape facilitates signing and lip reading by providing clear sight lines from speaker to listener.
A round dining table is better than a rectangular table because it provides clear sight lines.
Visual signals such as flashing lights can provide important visual cues. The lights are activated by the telephone, doorbell, alarm clock, fire alarm/smoke detector, or a crying baby. The lights can be placed in panels at strategic locations throughout the house.
Because of the addition of extra electronic devices, adequate outlets should be planned to avoid the unnecessary use of extension cords.

Design for Visual Impairment

People with impaired vision rely heavily on the senses of hearing and touch. Consequently, tactile indicators and acoustics are critical for day-to-day activities in familiar environments and for way finding in unfamiliar public spaces.

Things to consider:

The blind need tactile warning of danger. Door handles may be textured to indicate a dangerous area beyond the door, and landings and curbs can be textured to indicate steps or changes of grade.
Outdoor, hanging or projecting objects (even plants and tree branches) that extend into the path of the blind person should be avoided, Where there is more than one storey, a handrail should extend continuously, from floor to floor, rather than stopping at the landing.
Signage is important. Small groups of letters and numbers can be easily read with the fingers, but larger groups of letters and long texts are difficult for the blind to read.
Persons born blind learn Braille, while most persons blinded later in life do not. Signage should include both letters/numbers and Braille symbols.
To be useful, tactile signals and signage should be uniform throughout a building.
Audible signals for the blind are helpful at crosswalks, in elevators, and for emergency systems such as smoke detectors/fire alarms.
Gas cook tops tend to be better for the blind because the gas makes a sound as it burns. In addition, electric elements retain heat after they are turned off, which can be dangerous. Controls should be mounted where the blind will not have to reach over the flame or to operate the cook top.
A lip on the counter may be helpful in preventing objects from being pushed off the edge. Furniture should have rounded corners and some padding of table edges may be advisable.
A hook next to electrical outlets might be desirable to hang a plug where it can be found easily
Changes of grade in flooring materials are obstacles for the blind and should be avoided.

Design for the Elderly

People are living longer today than ever before. As a result, the elderly population is growing rapidly and becoming an important political and social force. The concerns of the elderly include limited mobility, loss of hearing, and loss of visual acuity. Consequently, all of the considerations listed above apply to the elderly. There may also be loss of memory or other cognitive function that makes some tasks more difficult.

Things to consider:

Visual contrast is important in judging space and distance. For example, a countertop should be light or dark in value to contrast with the floor. This helps with depth perception and makes the edges more obvious. The same is true for a tabletop, where depth perception is important.
In some public spaces and facilities designed for the elderly, way finding is important. In a long hallway the location of doors can be indicated with a slight recess in the wall surrounding the doors. Distinctive pieces of furniture and art can be visual reminders of location. Color coding of areas or floors may also prove helpful.
Decreased control over bodily functions may make it desirable to select textiles for upholstery that have been specially treated to resist moisture or laminated with a thin layer of plastic.

Other Special Populations

Other special populations include children, the mentally ill, the terminally ill and many others. Unlike the design needs of those with physical impairments, the design needs of these groups do not always lend themselves to universal design. The considerations associated with these groups are important and worthy of designers attention.

Environmental Considerations

Designers have an ethical responsibility to be aware of the impact their designs have on the environment. That responsibility includes ensuring the aesthetic quality of the design so that it will not be prematurely discarded, as well as avoiding waste and pollution. Everyone benefit when the environment is managed wisely.

Design Longevity and the Environment

Good design stands the test of time and adds quality to a community indefinitely. Historic sites or buildings often add value to an area. But poor design may never live to become historic; it will be razed to make way for new development. Older, but viable, buildings that no longer serve their original purposes have been given new life by thoughtful design changes. Good design can create and preserve communities that are pleasant and a genuine source of pride. Long-lasting design is a friend of the environment.

Things to consider:

Encourage community governments to establish design-review commissions to monitor design quality and establish design criteria for builders and developers.
Encourage local governments to establish greenbelts and preserve green spaces as well as engage in city forestation or tree planting.
Encourage preservation and adaptive reuse of existing-buildings.

Waste in the Environment and Green Products

There are two types of resources used by builders and developers: renewable and nonrenewable. Fortunately, some forms of both renewable and nonrenewable resources, such as metals, plastics, and paper products, can be recycled. When buildings are demolished or interiors refurnished, the remnants will not magically disappear; they have to be removed to a landfill unless they can be recycled. Space for landfills is increasingly hard to find, and good ethics point to recycling. In order to be environmentally sound, materials, finishes, and furnishings should be chosen for good design and quality, which in turn produce longevity and decrease waste. When they do wear out, materials, finishes, and furnishings should be recycled whenever possible.

Things to consider:

Select and specify materials and finishes that will wear well. Reupholster furniture rather than discard it.
Specify systems furniture (modular office landscape) from manufacturers that will refurbish their product when it is dated or worn.
When possible, specify blanket wrapping rather than cardboard packing for shipping or new furniture.
In appropriate settings, specify patterned carpets that will hide soil and wear and extend its life.
Recycle whenever possible, and encourage recycling by designing recycling centers in residential and non-residential facilities.
Encourage recycling in local communities. Specify green products whenever possible.

Air Pollution in the Interior Environment

Some buildings are uninhabitable because of poor air quality that causes users to become ill. This problem is sometimes referred to as “sick-building syndrome. Many of the toxins found in interior air can be mitigated by plants. Plants have the ability to clean the air naturally; when well cared for, they also provide a wonderful aesthetic quality of life to the interior space.

Things to consider:

Allow at least twenty-four hours of good ventilation for off-gassing of new furnishings.
When possible, specify particle board and plywood products without formaldehyde.
Make whatever design decisions are necessary to ensure adequate air circulation.
Ensure that fresh-air intakes for HVAC systems are away from locations where automobile exhaust will be present.
Work with local governments to prohibit smoking in public facilities.
Ensure that building foundations are carefully sealed to prevent rodent contamination. Use plants to clean the air naturally.

Lighting and Energy Conservation

Efficient electric lighting and increased use of natural light could save up to 90 percent of the electricity.

Things to consider:

Wherever possible, use LED lighting.
Use higher levels of light only where and when needed to accomplish specific tasks. Use dimmers and timers to save energy and extend the life of incandescent lamps.
Use natural light from windows wherever possible before resorting to electric lighting.
Also consider clerestories, skylights, light pipes, and atria to bring natural light into a building.

Windows and Energy Conservation

On average, 10 to 25 percent of internal heating or cooling is lost through windows, and similar amounts of heat gain occur through windows during warm seasons and in warm climates. Low-tech solutions and new high-performance window technologies can improve those statistics.

Things to consider:

Wherever possible, specify high-performance windows for new construction.
Insulate and caulk window frames.
Use low-tech solutions such as planting deciduous trees (those that lose their leaves seasonally) to block the sun’s direct rays in the summer and let in the sun’s rays in winter.
Design overhangs to block summer sun and a winter sun as the sun’s angle changes seasonally:
Use screens or awnings for additional sun control.

Conclusion

We conclude by emphasizing that issues of environment and universal access are ever present in the process design and not merely special considerations to be discussed in isolation. The ideas and recommendation presented should be applied to all. Whether focus is on electrical systems and lighting, fabrics, or historical styles, it is important to take advantage of whatever opportunities are available to maximize the accessibility and environmental friendliness of every design project. This is not only good ethics but good design sense.

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References:

Nielson.K.J.,Taylor.D.A., (2002), Interiors An Introduction, Mc Graw Hill Publication.
Seetharaman and Pannu., (2009), Interior Design and Decoration,CBS publishers.
Faulkner and Faulkner (1994), Inside Today’s Home, Holt, Rinehart and Winston, NewYork.
Gandotra.V, Shukul.M, and Jaiswal.N, (2011), Introduction to Interior Design and Decoration, Dominant Publishers and Distributors New Delhi.