By Graham Barker

There are many key design considerations for lifts and escalators in offices which affect building layout and apply regardless of the office type, such as:

  • Expectation of lift service provision and the terminology used to describe lift performance
  • Movement of goods
  • Accessibility for all
  • Health and Wellbeing

Expectation of lift service provision

Historically the words such as ‘poor, average, good and excellent’ were used to classify lift system performance. This classification system is associated with calculations to assess the lift performance of a building. These lift traffic analysis calculations remain valid today for simple office designs but have been superseded by developments in our ability to model more complex office configurations and associated lift systems using computer-based statistical lift traffic analysis simulation software.

The lift performance is assessed at peak lift usage times, in an office environment these are usually morning and lunch times. Guidance on the level of lift performance required in an office is generally referred to the British Council for Offices (BCO) Guide to Specification, and CIBSE (Chartered Institute of Building Services Engineers) Guide D. Although these documents are UK specific, they are often used as good practice in office design for projects around the world.

In general, most office developments within the UK will want to achieve the performance guidance recommended by BCO for the development to be marketable and attractive to potential tenants.

Lift Traffic Analysis Simulation or Calculation?

It is worth noting the difference between a lift traffic simulation and a calculation:

  • A calculation is clearly defined and repeatable by anyone, anywhere – if the same numbers are used then the answer will be the same
  • In simulation there are a multitude of variables to input, and, as it’s a statistical analysis, the answers are not the same every time

In the wrong hands lift traffic simulation software can provide a result which may look acceptable, but is not, as the method or variables have been incorrectly interpreted.

Simulation can analyse much more complex building designs than calculation, however, calculation can be simpler and more time-efficient to do.

What are the terms used by VT Engineers and lift consultants to describe lift performance?

In association with the move to computer-based lift traffic analysis simulation, the terminology we use to express the expected lift performance has changed.

Waiting time – the time a lift user would be waiting in the lift lobby for a lift to arrive after they have pressed the lift call button

Transit time – the time that the lift passenger spends travelling in the lift to their destination floor

Time to destination – the total time a lift passenger experiences in their lift journey, which is the total of the Waiting and Transit time.

We use complex statistical simulation software which models the lift journeys of an individual passenger, running hundreds of simulated lift journeys and then averaging the results, which is why the terms ‘average waiting time’ and ‘average time to destination’ are used. These terms are often abbreviated:

Average Waiting Time = AWT

Average Transfer Time = ATT Average Time To Destination = ATTD

Movement of Goods

The movement of goods within an office should never be an afterthought and can have a significant impact on the lift requirements for a building. Some of the factors to consider concerning goods lift provision in offices are:

Goods lift location – is it accessible to all tenants? Can floor plates be subdivided for multiple tenancies whilst still providing goods lift access for all tenants? Is the lift visible Front Of House (FOH) or is it to be hidden from the view and access of normal building users at the Back Of House (BOH)?

Goods lift size – both load capacity and physical size of the goods lift are important. What size of goods lift does an office require?  The answer should incorporate moving day-to-day goods; for occasional goods such as furniture or fit-out materials; or to assist with the movement of replacement equipment for building maintenance.

Dedicated or shared use with passengers – will it be acceptable to only use the goods lift in quiet periods when lift passenger demand is reduced? If goods lifts are likely to be regularly used for movement of waste materials or food, then it may be difficult to keep them clean for passenger use.

Deliveries – an office’s postage strategy is a key consideration in the modern age, but not generally due to post. Most office buildings see a large volume of incoming deliveries every day for office users, having personal items delivered to them at their place of work as they will not be home to accept the delivery. Many office buildings find the volume of personal deliveries to office users can keep a goods lift busy all day long.

Accessibility for all

When we think about lift accessibility in buildings our minds are often drawn to thoughts of wheelchairs and ensuring lifts are suitably sized, something which is defined within Building Regulations Part M as well as lift standards which require lifts to be sized at a minimum 1100 x 1400 mm in a new building.

It is important to also consider the less obvious accessibility requirements:

Blindness and Visual Impairment – ensuring reflective contrast between surfaces so that partially sighted people can identify the location of controls.

Deafness and Hearing loss – providing a visual indication of lift operation so those that have hearing difficulties can pick up on visual signals. Also, the inclusion of inductive loop technology to assist hearing aid wearers.

Inclusive Cycling – whilst a large proportion of cyclists will use a standard two-wheel bike, there are other types of cycles such as recumbents, handcycles, and tricycles. When considering access to cycle storage locations, particularly when located at a floor other than the ground floor, access for all types of cycles should be considered.

Wheelchair type – not all wheelchairs are the same. Powered, all-terrain, and sports wheelchairs are typically larger than a standard manual wheelchair and may require a lift which is larger, or with wider lift doors.

Wheelchair Turning – Most lifts have a single entrance making it necessary for a wheelchair user to reverse out of a standard lift, an operation which can be hazardous due to limited visibility of the lift landing. Providing a lift sized at 2000 x 1400 mm allows a wheelchair user to rotate within the lift and exit in a forward direction with much improved visibility.

Health and Wellbeing

When considering the health and wellbeing of office users within the design of a building, in conjunction with the vertical transportation system, the primary aim is to offer building users ways not to use lifts or escalators.

Prominent and attractive stairs, positioned as a viable alternative to lift or escalator use, can reduce the requirements for lifts and escalators within a building – whilst improving the health and wellbeing of office users by incorporating exercise into the working day.

This offers a win-win scenario where building users get more physical exercise, and the space taken by the lifts and escalators can be reduced, creating additional net lettable area.

A staircase between floors can also lead to greater interaction and communication between workers on different office floors. At Cundall’s Birmingham office we have seen the marked improvements a stair between floors can provide, for more information see here

Additional features can be incorporated within the office lift and escalator design which will support the fight against COVID-19 such as:

  • Non-contact lift buttons
  • Phone apps to call a lift
  • Increased lift ventilation
  • Lift air purifiers
  • Escalator handrail sanitisers

For more specific information on this topic why not read my article on the latest products to make your lifts and escalator COVID-19 safe.

Lift consultancy for office developments

There are many ways in which a lift consultant can help to improve the value and operation of office buildings, through the thoughtful specification of the vertical transportation equipment.

No two projects are the same, if you’d like to discuss how the Cundall vertical transportation team can assist you with your office design, construction or refurbishment project please get in touch.

This series of blogs aimed to provide some thoughts, coupled with experience from previous projects, to assist with the reader’s future building designs and the associated lift and escalator design considerations. To discuss in more detail please don’t hesitate to contact the writer or comment below.

Part 2 will cover – making the right choices during lift design

Part 3 will cover – Lift design for the redevelopment of existing office buildings

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Graham Barker, Uncategorized, Vertical Transportation, Workplace

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