Lifts (also known as elevators) are an essential feature of modern buildings and provide vertical transportation for people and goods. Proper planning of lift arrangements and dimensions is crucial to ensure safe and efficient operation of the building.
The appropriate aspect of lift installation shall be discussed during the preliminary planning of the building with all concerned parties, namely, client, architect, consulting engineer and/or lift manufacturer. This enables the lift manufacturer to furnish the architect and/or consulting engineer with the proposed layout or vice-versa.
1) Exchange of Information
Information to be exchanged on vital matters such as:
- Number, capacity, speed and disposition of the lifts necessary to give adequate lift service in the proposed building.
- Provision of adequate access to the machine room.
- Loads which the lift will impose on the building structure, and the holes to be left in the machine room floor and cut-outs for wall boxes for pushbuttons and signals.
- Necessity for and type of insulation to minimize the transmission of vibration and noise to other parts of the building.
- Special requirements of local authorities and other requirements set out in the planning permit.
- Need for the builder to maintain accuracy of building as to dimensions and in-plumb.
- Periods of time required for preparation and approval of relevant drawings for manufacturing and the installation of the lift equipment.
- Requirements for fixing guide brackets to the building structure.
- Time at which electric power will be required before completion to allow for testing.
- Requirements for electrical supply feeders, etc;
- Requirements for scaffolding in the lift well and protection of the lift well prior to and during installation of equipment; and
- Delivery and storage of equipment.
2) Information to be provided by Architect or Engineer
As a result of preliminary discussions, the drawings of the building should give the following particulars and finished sizes:
- Number, type and size of lifts and position of lift well.
- Particulars of lift well enclosure.
- Size, position, number and type of landing doors.
- Number of floors served by the lift.
- Height between floor levels.
- Number of entrances.
- Total headroom.
- Provision of access to machine room.
- Provision of ventilation and, if possible, natural lighting of machine room.
- Height of machine room.
- Depth of lift pit.
- Position of lift machine, above or below lift well.
- Size and position of any trimmer joists or stanchions adjacent to the lift well at each floor.
- Size and position or supporting steel work at roof levels.
- Size and position of any footings or grillage foundations, if these are adjacent to the lift pit; and
- In the case of passenger lifts whether the lift cage is required to carry household luggage, such as refrigerator, steel almirah, etc.
- The lift lobby should be designed appropriately since this has bearing on the traffic handling especially when more number of lifts are involved.
- In a dual line arrangement (lifts opposite to each other) the lobby should be between 1.5 times and 2.5 times the depth of one car.
- Typically, the greater the number of lifts, the bigger the multiplier to be used.
- As an example, a quadruplex may use 1.5 to 2, whereas an octuplex will need 2 to 2.5.
- For in-line (single line) arrangements, the lobby can be typically half of the above recommendations.
- It is preferable that the lift lobby is not used as a thoroughfare.
- If unavoidable the lift corridor shall take into account space for people who are moving.
- When submitting application for a building permit to the local Authority, the building plans shall include the details of lifts (number of lifts duly numbered, location, type, type of doors, passenger capacity and speed).
3) Positioning of Lifts
- A thorough investigation should be made for assessing the most suitable position for lift(s) while planning the building.
- It should take into account future expansions, if any.
- Though each building has to be considered individually for purposes of location of lifts, factors influencing the locations of passenger and goods lifts are given in (Passenger Lifts to Hospital Bed Lifts) given below.
4) Arrangement of Lifts
- The lifts should be easily accessible from all entrances to the building. For maximum efficiency, they should be grouped near the centre of the building.
- It is preferable not to have all the lifts out in straight line and, if possible, not more than four lifts should be arranged in this manner. If more than 4 lifts have to be grouped together in a straight line, then destination control systems would require to adopted. Further, the corridor should be wide enough to allow sufficient space for waiting passengers as well as for through passengers.
- In some cases when there are more than three lifts, the alcove arrangement is recommended. With this arrangement, the lift alcove leads off the main corridor so that there is no interference by traffic to other groups or to other parts of the ground floor. This arrangement permits the narrowest possible corridors and saves space on the upper floors.
- Walking distance to the individual lift is reduced and passenger standing in the centre of the group can readily see all the lift doors and landing indicators.
- The ideal arrangement of the lifts depends upon the particular layout of the respective building and should be determined in every individual case. Some typical recommended arrangements are given in Figure below.
5) Passenger Lifts
i) Low and medium class flats
- Where a lift is arranged to serve two, three or four flats per floor, the lift may be placed adjoining a staircase, with the lift entrances serving direct on to the landings.
- Where the lift is to serve a considerable number of flats having access to balconies or corridors, it may be conveniently placed in a well-ventilated tower adjoining the building.
ii) Office buildings, hotels and high-class flats
- In general, the arrangement as recommended in Arrangement of Lifts above, should be followed.
- However, in case this is not possible, it is desirable to have at least a battery of two lifts at two or more convenient points of a building.
- If this is not possible, it is advisable to have at least two lifts side by side at the main entrance and one lift each at different sections of the building for inter-communication.
- When two lifts are installed side by side, the machine room shall be suitably planned with sufficient space for housing the machine equipment.
- The positioning of lifts side by side gives the following advantages:
- All machines and switch gear may be housed in one machine room,
- Lifts can be inter-connected more conveniently from an installation point of view, and
- Greater convenience in service owing to the landing openings and each floor being adjacent.
iii) Shops and departmental stores
- Lifts in shops and stores should be situated so as to secure convenient and easy access at each floor.
- For buildings with more than 12 floors, where passenger and service lifts are provided in one lobby, it is recommended to have group control for all the lifts.
6) Goods Lifts
- The location of lifts in factories, warehouses and similar buildings should be planned to suit the progressive movement of goods throughout the buildings, having regard to the nature of position of the loading platforms, railway sidings, etc.
- The placing of a lift in a fume or dust laden atmosphere or where it may be exposed to extreme temperatures, should be avoided, wherever possible.
- Where it is impossible to avoid installing a lift in an adverse atmosphere, the electrical equipment should be of suitable design and construction to meet the conditions involved.
- Normally goods lifts have lower speeds than passenger lifts for the same travel because traffic conditions are less demanding, and more time is required for loading and unloading.
- As loads for goods lifts increase in size and weight, so the operation of loading and unloading becomes more difficult.
- Therefore, it is usual to require greater accuracy of levelling as the capacity of the goods lift increases.
- A large capacity goods lift operating at high speed is often a very uneconomical solution.
- The inherent high cost is enhanced due to the very small demand for such equipment, much of which is custom made.
- The high capital cost of the lift, building work and electrical supply equipment usually shows a much smaller return as an investment than more normal sizes of lifts.
7) Hospital Bed Lifts
- Hospital bed lifts should be situated conveniently near the ward and operating theatre entrances.
- There shall be sufficient space near the landing door for easy movement of stretcher/bed.
- It is convenient to place the passenger lifts in a hospital, near the staircases.
8) General Arrangement Drawings (GAD)
- The general arrangement drawings should be prepared by the lift manufacturer.
- The lift manufacturer requires sufficient information for the preparation of working drawings and is usually obtained from architect’s drawings supplemented by any information obtained from the site and by collaboration with the other contractors.
- General arrangement drawings showing the layout of lifts duly numbered, details of builder’s work, for example, holes in walls for guide fixing, holes in machine room floor for ropes and conduits, recesses for landing sills, supports for lift machine and loads imposed on the building should be submitted by the lift manufacturer to the architect/engineer for written approval.
9) Lift Arrangements
The lifts arrangement in a building is determined by several factors, including the building’s size, occupancy, and usage patterns. Here are some key considerations when planning lifts arrangements:
- Traffic flow: The lift arrangement should be designed to accommodate the expected traffic flow. For example, in a high-rise building with a large number of occupants, multiple lifts may be required to avoid long waiting times.
- Occupancy: The occupancy of the building will determine the number of lifts required. A building with a high occupancy will require more lifts than a building with low occupancy.
- Special requirements: Buildings with specific requirements, such as hospitals, may require specialized lift arrangements to accommodate patient transport, medical equipment, and staff.
- Building design: The building’s design can also affect the lift arrangement. For example, buildings with irregular floor plans or high ceilings may require customized lift solutions.
10) Planning Dimensions
The planning dimensions of a lifts refer to the physical dimensions required for the lifts to operate safely and efficiently. The following are some key planning dimensions to consider:
- Lift Car Size: The size of the lift car is determined by the expected occupancy, traffic flow, and the type of building. The standard lift car size is around 2.5 meters deep and 1.5 meters wide.
- Door Width: The door width should be wide enough to accommodate the expected traffic flow. The standard door width is around 900mm.
- Lift Pit Depth: The lift pit is the space below the lift car, and the depth of the pit is determined by the lift’s suspension system. The standard lift pit depth is around 1.5 meters.
- Headroom: The headroom is the distance from the top of the lift car to the ceiling of the lift shaft. The headroom should be at least 2.5 meters to accommodate the lift’s suspension system.
- Shaft Width: The shaft width is determined by the size of the lift car and the expected traffic flow. The standard shaft width is around 1.8 meters.
In conclusion, proper planning of lift arrangements and dimensions is essential to ensure safe and efficient operation of a building. Building owners and designers should carefully consider factors such as traffic flow, occupancy, special requirements, building design, lift car size, door width, lift pit depth, headroom, and shaft width when planning a lift installation.