Planning for internal circulation

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Building users need to understand where they are, where they are going, and the route to take to get there. They then need to successfully move through the physical environment to reach their destination.

Orientation and wayfinding

The purpose of the building will undoubtedly determine how the internal space is to be arranged. Building users need to be able to enter the building, get to those spaces and move between them. The more complex the building, the more difficulty that new or less frequent building users will have, especially those who are blind or have low vision.

The layout of circulation space needs to be logical, with good sightlines. Some building users may not wish to enter areas where the ceiling heights are low, corridor widths are restricted or light levels limited. Curving corridors will lead to orientation problems and sharp corners present some with security concerns.

Simple, logical and consistent layouts enable people to memorise environments that they use regularly and predict and interpret environments they are encountering for the first time.

Visual links through windows to the outside environment can reduce stress and help with orientation. Grouping facilities such as co-locating lifts, ramps, stairs and escalators, or keeping all the sanitary facilities in the same place on all floors, results in a more predictable environment which is easier to understand.

The success of wayfinding will be affected by the number of decision points on a particular route and the quality of information available. That information could be environmental (for instance from the structure of the building, or from the colour or texture of finishes) to wayfinding-specific (such as floor plans, signage or room numbers on doors). The better the environmental information, the less wayfinding-specific information that will be required. Consistency in design assists with wayfinding.

Signage should be located at decision points and perpendicular to the path of travel.

Some building users may not be able to navigate their way through the environment and need assistance. In this event, management procedures need to be in place to assist them in getting to, and returning from, their desired destination.

Design considerations

• Ensure the internal layout of a building takes account of the need for people to use circulation routes and provides as much wayfinding assistance as possible.
• Ensure circulation spaces are logical with good sightlines within an environment.
• On circulation routes provide visual links with the outside wherever possible. 
• Avoid glare in the internal environment.
• To make the environment predictable and easy to understand, group provisions and facilities of the same type together. 
• In open plan areas and where doors are omitted, ensure circulation routes are clearly defined.
• Ensure that assistance can be given to building users who find navigating the internal environment difficult.

Physical movement

Travelling towards a destination within a building will consist of horizontal and vertical movement for the building user.

In the horizontal plane the limiting factors may be the distance to be travelled, the width of routes, the type of floor surface, and the presence of obstructions such as doors with door closers. In the vertical plane the limiting factors may be the gradient and rise of ramps, the number and pitch of stairs, the size or design of a lift or the absence of suitable alternatives.

Horizontal circulation

People carrying objects, those with young children or users with mobility and strength limitations may find long distances a major barrier and take longer to reach their destination than others. Consequently, travel distances should be kept to a minimum. The incorporation of additional entrances with associated car parks can help reduce the length of walking required. Seating at regular intervals is also helpful.

Doors are a barrier not only because they need to be opened but also because they often restrict the width of a route. Wherever environmental, privacy and security requirements allow they should be omitted. As an example, configuring the layout of a toilet facility to restrict sightlines can remove the need for doors on the approach, saving money and improving access.

Doors can pose a problem when they are fitted with door closers. These can become increasingly heavy if they are not maintained.

Internal lobbies can cause problems as they often require effort to open the doors and require the negotiation of a small space. Where they are required they should be made as easy to use as possible.

Open plan areas are beneficial as they reduce the need for internal doors or other divisions which often impede access. However, people who are blind or have low vision find crossing large areas without appropriate environmental and tactile guidance or cues difficult.

Non-vertical columns can cause confusion and create headroom issues and should not be placed near circulation routes.

Design considerations

• Design circulation spaces to restrict travel distances.
• Consider the use of additional entrances and associated car parks to ensure facilities are all within easy walking distance.
• Where travel distances are long, provide seating and toilets at regular intervals. 
• In airports or similar large buildings, travellators can be installed where long distances are unavoidable. Restrict the length of the travellators to ensure that facilities or destinations are not bypassed.
• Consider the provision of transport between areas separated by long distances.
• Wherever possible, omit doors from the design.
• Isolate quiet areas in buildings by a buffer zone to avoid the need for doors.
• Avoid the need for lobbies wherever possible. Where they are necessary, ensure they are large enough not to be restrictive.
• If non-vertical columns are essential to the design ensure that circulation routes keep away from them.

Vertical circulation

Changes of level in buildings can be a problem for some building users. Not only are stairs, lifts and ramps costly, they also take up space which might be better utilised for another purpose.

For people who cannot or prefer not to use the stairs, a passenger lift is generally the most convenient method of travel between floors in a building. Passenger lifts have the advantage of being able to move a number of people quite quickly, although some people do not like entering a lift car. Sufficient lifts should be provided in convenient locations to suit the building use and expected occupant demands.

Where the installation of a lift is not immediately practical, the construction of a lift shaft with knock out floor panels and space for control equipment could save huge costs in the future. In the interim, the spaces on each floor could be used as cupboards.

Escalators can move large numbers of people quite quickly but some building users do not feel safe on them. When they fail (either through mechanical faults or perhaps a power outage during an evacuation) the result can be an extremely long staircase with high risers and sharp nosings.

Escalators do not provide a means of access for all and are unsuitable for wheelchair users, people pushing strollers and buggies, and some people with disabilities.

Stair lifts and chair lifts are slow, have high maintenance requirements and are generally only able to carry one passenger at a time. Limited weight capacity and size means they are unsuitable for regular use with larger power chairs. They can be effective in domestic environments but should not be installed in a public building.

Where the installation of a passenger lift in an existing building is not possible (such as in historic buildings) platform lifts could be considered.

Stairs are a standard way to link floors but their design can create problems for many building users.

A single isolated step is the most difficult change in level to perceive, presents a high trip and fall hazard for all users and should not be installed.

Ramps provide step-free access between levels but for people who are unable to incline the feet, or are using callipers, they present a barrier.

While portable ramps could appear to solve some immediate accessibility problems, they require a management input, present a trip hazard to others and are often too steep for independent use.

Design considerations

• Wherever possible, design sites and buildings to provide consistently level access thus avoiding the need for steps and ramps.
• Wherever possible, avoid changes in level within a storey.
• Provide lift access to all floors in multi-storey buildings where possible.
• Where lift access to every upper floor is not possible, provide all necessary facilities on accessible floors.
• If a lift is not provided, consider constructing a lift shaft so that a lift can be installed at a later date.
• Position stairs, lifts, ramps and escalators in the same location to allow building users to choose their preferred method of changing level.
• In existing buildings install passenger lifts in preference to other types.
• Use portable ramps only as a temporary measure in exceptional circumstances.
• Avoid the possibility that service ramps might be used as part of a circulation route.
• Single steps should not be installed or be available for use except in existing buildings where alterations are not possible.

Building Code requirement

Building Code clause D1 Access routes:

D1.3.1 Access routes shall enable people to: (c) move into spaces within buildings by such means as corridors, doors, stairs, ramps and lifts.

D1.3.2 At least one access route shall have features to enable people with disabilities to: (b) have access to the internal space served by the principal access, (c) have access to and within those spaces where they may be expected to work or visit, or which contain facilities.

D1.3.3 Access routes shall: (a) have adequate activity space, (e) include stairs to allow access to upper floors irrespective of whether an escalator or lift has been provided, (i) not contain isolated steps.

D1.3.4 An accessible route, in addition to the requirement of Clause D1.3.3, shall:

(a) be easy to find, as required by Clause F8 Signs
(b) have adequate activity space to enable a person in a wheelchair to negotiate the route while permitting an ambulant person to pass
(c) include a lift complying with Clause D2 Mechanical installations for access to upper floors where:

(i) buildings are four or more storeys high
(ii) buildings are three storeys high and have a total design occupancy of 50 or more persons on the two upper floors
(iii) buildings are two storeys high and have a total design occupancy of 40 or more persons on the upper floor, or
(iv) an upper floor, irrespective of design occupancy, is to be used for the purposes of public reception areas of banks, central, regional and local government offices and facilities, hospitals, medical and dental surgeries, and medical, paramedical and other primary health care centres.

(f) have doors and related hardware which are easily used.