Central to an inclusive approach is the challenge of understanding and quantifying the numbers of people adversely affected by decisions made during the specification and design process. The 'design exclusion' takes several forms: older and disabled people suffer from it; so do economically vulnerable groups and those affected by changing technologies and work practices.

Senior management, design managers, marketing and branding executives, and purchasing and sales personnel all have a part to play in the delivery (or non-delivery) of inclusive design, and consumers have a key role in driving the process. There are many things that can make an inclusive environment one that every user of a facility can benefit. Organisations can see real rewards as individuals and people use that facility more and more for it's user friendly design to customers and employees.

Disability - the reasons for change

Currently, one billion people worldwide have a noticeable degree of functional impairment.

In the UK, 8.7 million people come under the remit of the Disability Discrimination Act 1995 (DDA). Fewer than five per cent are wheelchair users. Collectively they have an estimated disposable income of £45-50 billion.

There are 6.2 million disabled people of working age in the UK, equivalent to 18% of the working population (Labour Force Survey, summer 1998).

One out of every four consumers is disabled or has a disabled person in their immediate circle.

In the UK, 7.2 million people work as carers or personal assistants and so are sensitised to issues of access and usability as they impact on those they assist and care for.

Glossary of terms used regarding disability

This glossary is not in alphabetical order. One intention is to familiarise readers of this page with key terms and expressions. Another is to give an overview of the theory and practice of inclusive or universal design, and the changing attitudes of older and disabled people.

Social inclusion - A Europe-wide political objective, aimed at combating social discrimination, marginalisation and conflict due to age, disability, poverty or ethnicity. Particularly important due to the diversity of ethnic groups in the enlarged EU.

Medical model - The medical model of disability and ageing implies that people are disabled as a consequence of their own condition, and seeks to either remedy the impairment through medication, rehabilitation and surgery, or through adaptive aids and equipment.

Social model - In contrast, the social model, which has superseded the medical model, sees people as disabled or enabled by the social context in which they function and proposes that changes in the social context or environment can remove or alleviate disability.

WHO standard model - First published by the World Health Organisation in 1980, and based on the medical model, this described a cascade of effects from impaired capability to handicap, shifting the emphasis away from medical to environmental and social conditions.

Revised WHO model - The standard model was replaced (Nov 2001) with a new International Classification of Functioning, Disability and Health (ICF). This shifts the focus to life quality and how we function in social and other contexts, which can be improved by design.

Health condition/status - Terms used by the WHO to group disease, congenital and other factors previously dealt with in more strictly medical terms, allowing them to be seen as falling within a continuum of health conditions which all impact on life quality and capability.

Impairment - Health conditions, ageing, and traumatic events can all result in impaired capability. Whether this gives rise to disability is determined by social and environmental factors, and importantly the design of environments, products, systems and services.

Disability - In the past, people were seen as disabled by their condition. Now the move is towards understanding disability as the result of a mismatch between individuals and their social and physical environment. PC terminology differs from country to country.

Ageing - The ageing process is characterised by the acquisition of progressive multiple minor impairments predominantly related to sight, hearing, dexterity, mobility and cognition. In combination these can lead to high levels of disability and dependency.

Independence - For older people independence is crucial. This can be compromised by inappropriate design, and is conditional on being able to carry out daily living activities like bathing, dressing, cooking, contact with family and friends and social participation.

Participation - Participation and social integration are key factors. Some severely disabled people prefer the help of a personal assistant where activities are time-consuming to perform. Priorities for younger disabled people are fulfilment and social involvement.

Design for disability - There is a significant tradition of design for disability, mainly focused on aids and adaptations. Related to the medical model of disability (and ageing), the underlying intent is essentially prosthetic, originating in rehabilitation of war veterans.

Assistive Technology - Also referred to as rehabilitation design, and closely related to the above, but primarily focused on enabling social participation of people with severe impairments. Much work in this area has been concerned with developing one-off solutions and specialist equipment for small numbers of people.

Barrier-free design - The original focus of disability campaigners and architects was on barrier-free access to buildings and public environments - kerb cuts, textured paving, ramped entry, wider doorways, corridors and accessible toilets - all denoted by wheelchair symbol.

Accessibility - In addition to physical access, sensory access to buildings, services and information, via speaking browsers, sign language animations, Braille, etc. Now a legal requirement under disability discrimination legislation in the US, UK, etc.

Universal access - Access for all to information and communications technology (ICT). Also used in assistive technology to refer to specialist interfaces and control devices to make ICT products accessible to people with high levels of impairment.

Universal design - Term originating in the USA and underpinned by seven principles set out by architect and designer Ron Mace. Taken up enthusiastically in Japan. Extends barrier-free design and universal access to include access to products and services.

Transgenerational design - Concept developed by Prof James Pirkl and colleagues at the University of Syracuse, USA. Proposes that designs should work for people of all ages. Replaces universal design emphasis on disability with a market-led approach. Resulted in quality book of the same title.

Design for all - EU term equivalent to universal design, but with an emphasis on information. Current goal is the establishment of national centres of excellence in design for all education and dissemination across Europe. These are envisaged as virtual rather than physical centres.

Gerontechnology - Concept developed at Technical University of Eindhoven, Netherlands, with US and Finnish colleagues. Combines human factors, social sciences, gerontology and engineering. Applying technology to address age-related factors. Consumer/market oriented approach.

Inclusive design - Process-driven approach by designers and industry to ensure that products and services address the needs of the widest possible consumer base, regardless of age or ability. Emphasis is placed on working with 'critical users' to stretch design briefs.

User-(age, disability) friendly - Products, packaging, manuals, information, services, environments, and interfaces, etc, that have been designed for simplicity and/or ease of use, and are marketed, and promoted in ways that highlight user-(age, etc) friendly features and operations.

User-centred/focused design - Approach that places users at the heart of the design process, and involves and engages with users in ways that make them part of or integral to the design process itself. Similar terms, such as co-design, are used in architecture and planning.

EQUAL (Extend Quality Life) - R&D programme funded by UK research councils. Primary goal is to improve the life quality of older and disabled people by developing the necessary research base and technical expertise and transferring appropriate skills and technology to industry.

Design exclusion - Term developed by the i~design team of the Design Council to focus attention on those excluded by design features. The team has developed ways to quantify design exclusion based population data. If users must be excluded, such decisions should be rational and justified.

Inclusive design cube - A model developed by the i~design team of the Design Council which shows how four design approaches (described below) are needed to accommodate the needs of the whole population, in particular in product and interface design. Groups the following four design approaches within an inclusive design methodology.

User-aware design - Mainstream design that understands user needs and aspirations and so maximises the number of people who can use a product, service, or interface. This can only ever include a proportion of the whole population, making additional approaches necessary.

Customisable design - Computer-aided manufacture makes possible the customisation of individual products in production. A wide range of users can thus be accommodated within the overall specification of a product delivered as unique items matching individual requirements.

Modular design - Designs which, by virtue of interchangeable units or add-on elements, can be configured to meet a wide range of requirements, particularly with regard to the user interface, thus extending the range of users served by a single design or product.

Carer-assisted design - It is important that people who are reliant on carers are considered part of the whole population. This implies considering the needs of both user and carer. Importantly, older people are often cared for by spouses and relatives who are also elderly.

User research - Understanding users is key to inclusive and user-aware design. User research can be carried out by designers themselves, in which case it is likely to be based on empathic interaction with small groups of extreme users, supplemented by observation.

User research methods - There are several publications on user research methods including The Methods Lab (RCA) and USERfit (HUSAT for the EU). User-research is also carried out by specialist organisations such as RICAbility, market research companies, and academic groups.

Ethnography - Observing users in real-life situations and interacting with products is highly revealing. Small video cameras and desktop editing software make this a fertile and expanding form of research in social sciences and among the design community.