Skip to Content

Elevator Installation Requirements: Shaft Size, Pit Depth, Headroom and Power Supply

July 27, 2026 by
Paul Tchaparian

An elevator is not equipment that can simply be placed inside any available opening. Its capacity, speed, door arrangement, travel height and drive system all affect the building around it.

Before blockwork is completed or concrete is cast, the project team must confirm the elevator shaft size, pit depth, headroom, structural loads and power supply with the selected lift provider. Getting these details right early prevents expensive cutting, demolition, redesign and installation delays.

This guide explains the main elevator installation requirements for building owners, architects, consultants and contractors in Nigeria.

Important: The dimensions in this article are planning guidance, not construction dimensions. Final civil and electrical work must follow the approved, project-specific elevator layout drawings, structural calculations, manufacturer data and requirements of the relevant authorities.

The short answer

A complete elevator installation normally requires:

  • A straight, plumb and correctly sized shaft

  • A dry, waterproof pit of the specified depth

  • Sufficient headroom above the highest landing

  • Correctly formed landing openings and support points

  • A dedicated electrical supply with suitable protection and earthing

  • Safe access to the controller or machine space

  • Appropriate fire, ventilation, drainage, lighting and communication provisions

  • Approved structural, architectural and lift drawings that agree with one another

There is no single shaft size, pit depth or power rating that suits every elevator.

1. What determines the required elevator dimensions?

The building requirements cannot be finalised until several basic decisions have been made:

  • Lift purpose: passenger, home, hospital, service, cargo or accessibility lift

  • Rated capacity: the maximum passenger or goods load in kilograms

  • Number of floors and total travel: the vertical distance between the lowest and highest stops

  • Rated speed: faster lifts generally need greater safety clearances

  • Car size and door width: including wheelchair, stretcher or trolley access where required

  • Door arrangement: centre-opening, side-opening, single entrance or front-and-rear entrances

  • Drive system: traction, hydraulic or another approved system

  • Machine arrangement: machine-room-less, overhead machine room or a separate equipment space

  • Applicable safety, fire and accessibility requirements

A wider door can increase the shaft width. A deeper car can increase the shaft depth. Higher speed can increase both the pit and headroom. A through-car with doors on opposite sides also requires a different layout from a car with one entrance.

This is why an architect should obtain preliminary lift planning data before freezing the structural design.

2. Elevator shaft size

The elevator shaft, also called the lift well or hoistway, is the vertical enclosure in which the car and counterweight travel.

The shaft dimension means finished clear space

When a lift provider states a required shaft width and depth, these are normally clear internal dimensions. They must remain available after concrete irregularities, plaster, render, waterproofing, fire protection and other finishes are complete.

The team should confirm:

  • Clear internal shaft width and depth

  • Wall thickness and construction material

  • Landing-door opening width, height and position

  • Finished-floor levels at every landing

  • Shaft plumbness and permitted construction tolerance

  • Locations of guide-rail brackets, divider beams and other supports

  • Structural reaction loads and lifting points

  • Whether one or more entrances are required

Do not assume that the clear car size and shaft size are the same. Space is also needed for guide rails, brackets, car sling, counterweight, travelling cable, landing-door equipment, running clearances and safety components.

Keep unrelated services out of the shaft

The elevator shaft should not become a route for plumbing, drainage pipes, air-conditioning ducts, electrical services or equipment unrelated to the lift. Unauthorised projections can reduce safety clearances, obstruct installation and interfere with maintenance.

All beams, ledges and service penetrations should be coordinated with the approved elevator drawing before construction.

Typical shaft dimensions are only a starting point

Online tables may show a “standard elevator shaft size,” but even elevators with the same capacity can require different shafts because of their doors, speed, counterweight position and product design.

For early space planning, a common 8-person passenger car may require a clear shaft in the region of roughly 1.65–1.95 metres wide and 1.75–1.95 metres deep in some machine-room-less product configurations. This is an illustrative planning band only. It must not be used to cast a shaft or order an elevator.

The safest process is:

  1. Define the required capacity, car size, door opening, speed and number of stops.

  2. Obtain a preliminary layout from the lift provider.

  3. Coordinate it with the architectural and structural drawings.

  4. Issue an approved-for-construction layout before shaft work proceeds.

  5. Survey the completed shaft before manufacturing and installation milestones.

3. Elevator pit depth

The pit is the portion of the shaft below the finished floor level of the lowest landing. Pit depth is generally measured from the lowest landing’s finished-floor level down to the finished pit floor, subject to the selected system’s drawing convention.

The pit creates space for items such as:

  • Buffers and buffer supports

  • Guide-rail fixings

  • Car and counterweight clearances

  • Safety switches and stopping devices

  • A pit ladder and safe access

  • Lighting and an approved electrical outlet

  • Required refuge or survival space for technicians

How deep should an elevator pit be?

There is no universal answer. Pit depth depends on the lift type, capacity, speed, buffer arrangement and applicable safety standard.

As an illustration of this variation, official planning data for one passenger-lift family lists pit options of approximately 1,200–1,750 mm for certain 630–1,150 kg lifts at 1.0 m/s. For configurations in the same load range at 2.0 m/s, the listed range increases to approximately 1,550–2,500 mm. Special low-pit products may use less space, while faster, heavier or specialised lifts may need more.

These figures explain why reducing the pit after equipment selection can force a redesign or make the chosen elevator unsuitable.

The pit must remain dry

Water is one of the most damaging site conditions for elevator equipment. A pit should be:

  • Structurally sound

  • Properly waterproofed

  • Free from standing water and construction debris

  • Provided with an approved drainage or sump arrangement where required

  • Protected against groundwater and rainwater entry

Drainage must be coordinated so that it does not introduce another hazard or conflict with fire, environmental or lift requirements. A pump, when required, also needs a safe electrical supply, maintenance access and a discharge route approved by the project consultants.

Never use the lift pit as general building drainage.

4. Elevator headroom

Headroom is the vertical space above the highest landing. It is commonly measured from the highest landing’s finished-floor level to the underside of the lowest permanent obstruction at the top of the shaft, but the exact measurement reference must follow the lift provider’s drawing.

This space accommodates:

  • The car and car-top equipment at its highest position

  • Required safety clearances and refuge space

  • Door operator and travelling components

  • Guide rails and terminal stopping equipment

  • Machinery or pulleys located inside a machine-room-less shaft

  • Beams or lifting points specifically shown on the approved design

How much elevator headroom is required?

The answer depends on the car height, speed, equipment arrangement and safety configuration. In one current manufacturer planning guide, headroom for common passenger-lift configurations is calculated as the clear car height plus approximately 1,400–2,200 mm, depending on speed and car-top protection.

For a typical car height, that can place total headroom in the broad region of roughly 3.6–4.6 metres. This is only a conceptual range; some low-headroom solutions may require less, while high-speed, high-capacity or special lifts may require considerably more.

Roof beams, slabs, water tanks and mechanical services must not intrude into the approved headroom. A shortage discovered after the roof is cast can be difficult and expensive to correct.

5. Power-supply requirements for an elevator in Nigeria

Nigeria’s electrical supply framework uses nominal 230 V single-phase and 400 V three-phase systems at 50 Hz. However, this does not mean every lift can simply be connected to the nearest distribution board.

Many commercial passenger and goods lifts require a dedicated three-phase supply. Some small home lifts and specially designed systems can operate on single-phase power. The selected elevator’s electrical data sheet is the controlling document.

The electrical engineer and lift provider should agree on:

  • Required voltage, phase and frequency

  • Connected load, running current and starting demand

  • Required transformer or generator capacity

  • Cable type, size and route

  • Main isolator, breaker and fault rating

  • A lockable disconnecting arrangement

  • Earthing and protective bonding

  • Phase-failure, phase-reversal, over-voltage, under-voltage and surge protection

  • A separate circuit where required for car lighting, ventilation, alarms or controls

  • Controller and machine-space temperature and ventilation limits

  • Emergency communication and rescue-system supplies

Electrical work should be completed, tested and certified by appropriately authorised personnel. The Nigerian Electricity Management Services Agency states that electrical installations must be inspected, tested and certified before use.

Generator and backup-power planning

Do not assume that an existing building generator can safely run the elevator. Generator selection should consider:

  • Elevator starting and regenerative characteristics

  • Apparent power in kVA, not only motor kW

  • Other loads that will operate at the same time

  • Voltage and frequency stability

  • Transfer-switch sequence and delay

  • Whether one lift or several lifts must operate during an outage

  • Fire and emergency operating strategy

Modern variable-frequency drives can reduce starting demand, but the generator still needs to be checked against the actual lift data.

An automatic rescue device (ARD) is also not the same as full standby power. An ARD is generally intended to move the car to a nearby landing and release passengers after a power failure. It is not normally intended to keep the elevator in regular service throughout a long outage.

6. Structural and builder’s-work requirements

The lift transfers forces into the building through guide-rail brackets, beams, machine supports, buffers and other connection points. The lift provider should issue reaction loads and fixing requirements for review by the structural engineer.

Builder’s work may include:

  • Reinforced shaft walls or approved structural framing

  • Rail-support points or divider beams

  • Correctly sized landing openings

  • Door-sill supports and recesses

  • Machine or controller supports

  • Certified lifting beams or lifting points where specified

  • Safe access doors, hatches or platforms

  • Fire stopping around approved penetrations

  • Pit waterproofing and drainage

  • Permanent lighting and service sockets

  • Ventilation or cooling for equipment spaces

Never position reinforcement, beams or blockwork solely from an old tender drawing. The final arrangement should match the selected elevator.

7. Machine-room-less and machine-room elevators

A machine-room-less elevator places major drive components inside the shaft, which can save building space. It does not eliminate every equipment-space requirement. The controller, inspection controls and maintenance areas still require safe access and specified clearances.

A traditional machine-room elevator requires a dedicated room with the necessary:

  • Dimensions and access route

  • Structural capacity

  • Lighting and ventilation

  • Temperature control where specified

  • Electrical isolation

  • Fire protection

  • Working clearances around equipment

The choice should be made during design—not after the shaft and roof have already been completed.

8. Fire safety, accessibility and communication

Elevator planning must be coordinated with the building’s wider fire and accessibility strategy.

Depending on the building and approving authority, requirements may cover:

  • Fire-rated shaft and lobby construction

  • Smoke detection and lift recall

  • Emergency power or designated emergency operation

  • Two-way emergency communication

  • Accessible car and door dimensions

  • Reachable controls, tactile markings and audible or visual signals

  • Adequate lobby space and lighting

  • Firefighter or evacuation functions where specified

Nigeria’s National Building Code contains provisions for lifts, lift lobbies, fire separation and smoke detection. Nigeria’s accessibility regulations also contain requirements affecting passenger lifts in public and high-rise residential buildings. The project team should confirm the provisions applicable to the building type and state.

9. Common installation-planning mistakes

The most frequent problems are often created before the elevator reaches site:

  1. Casting the shaft from an unapproved or outdated drawing

  2. Measuring before plaster and finishes are considered

  3. Providing insufficient pit depth or headroom

  4. Allowing beams, pipes or ducts to project into the shaft

  5. Misaligning landing openings between floors

  6. Failing to waterproof the pit

  7. Ordering the lift before final floor levels are confirmed

  8. Undersizing the electrical supply or generator

  9. Omitting safe controller or machine-space access

  10. Changing car capacity, doors or finishes without rechecking the civil design

Correcting these issues can cost far more than completing a proper pre-installation survey.

10. Pre-installation checklist

Before elevator manufacturing or installation begins, confirm that:

  • The selected lift type, capacity, speed and number of stops are approved

  • Architectural, structural, electrical and elevator drawings agree

  • Shaft dimensions have been checked at several heights

  • Shaft plumbness and landing-opening alignment are within the approved tolerance

  • The pit depth is correct, dry, clean and waterproof

  • The headroom is unobstructed and matches the approved drawing

  • Required beams, supports and lifting points are complete

  • Finished-floor levels and sill details are confirmed

  • Main and auxiliary electrical supplies are installed and tested

  • Earthing and protective devices are complete

  • Generator and rescue arrangements have been verified

  • Safe access, storage and working areas are available

  • Required permits, inspections and certifications are planned

  • A joint pre-installation survey has been signed off

Plan the elevator before constructing the shaft

The best time to solve an elevator installation problem is before concrete is poured.

Early coordination between the building owner, architect, structural engineer, electrical engineer, contractor and lift provider ensures that the shaft, pit, headroom and power supply are designed around one approved elevator specification.

J&P Global Lifts and Elevators supports projects across Nigeria with lift planning, supply, installation and long-term service. If you are designing a new building or considering a lift for an existing property, share your drawings and project requirements with our team for a site-specific assessment.

Suggested call to action: Request an Elevator Site Survey

Frequently asked questions

What is the standard elevator shaft size?

There is no universal standard shaft size. It depends on the car capacity, door width and type, speed, counterweight arrangement, number of entrances and selected elevator model. Use only an approved project-specific layout for construction.

What is the normal pit depth for a passenger elevator?

Many conventional passenger-lift configurations require a pit greater than one metre, but the exact depth varies considerably. Some product configurations use approximately 1,200–1,750 mm at lower speeds, while faster or larger systems may require more. Special low-pit lifts are also available.

How much headroom does an elevator need?

Many standard passenger-lift arrangements fall within a broad planning range of about 3.6–4.6 metres above the highest finished landing. The final dimension depends on car height, speed, machinery and required safety space.

Does an elevator require three-phase power?

Many commercial elevators do, but some home and low-rise lift systems operate on single-phase power. Confirm the voltage, phase, frequency, kVA and protection requirements from the selected lift’s electrical data sheet.

Can an elevator be installed in an existing building?

Often, yes. The project first needs a structural and dimensional survey to determine whether an internal shaft, external shaft or specially configured low-pit and low-headroom solution is practical.