|Burj Khalifa_functions being devided by level|
The current trend toward urbanization throughout the world, particularly in developing countries, is creating a construction boom in the high-rise residential markets, in addition to traditional apartment buildings and owner occupied condominiums. Other types of high-rise residential buildings include serviced apartments associated with a major international hotelier’s brand image, owner-occupied condominiums that are only occupied during certain times of the year, time share rentals, etc. Each of these types of residential buildings requires different elevatoring solutions to properly service the building and residents.
Burj Khalifa features three sky lobby levels where residents and visitors transfer from an express elevator to local elevators. Sky lobbies also provide opportunities for amenities including pools, restaurants and roof garden access.Today, high-rise residential properties have also joined the ranks of the world’s tall and supertall buildings with the epitome currently exemplified by the Burj Khalifa in Dubai. Joining the ranks of the world’s tall and supertall buildings brings about many of the design challenges associated with high-rise commercial office buildings in terms of elevator design.
As an example, no longer can a person necessarily use a single elevator bank to reach his or her residence. High-rise supertalls require the use of a sky lobby strategically located and dividing the building into two or more shorter buildings stacked on top of one another. Each shorter building is then served by express sky lobby passenger shuttle elevators between the ground level and the sky lobby. Residents then transfer to local elevators serving that segment of the building, minimizing passenger waiting times and time to destination. In these cases, sky lobbies also provide opportunities for tenant amenities including spas, pools, cafes and restaurants, outdoor roof gardens, vertical gardens, etc. The different zones created by the stacking of shorter buildings on top of one another also provides the opportunity to offer different qualities of residences often with different entry lobbies within the same building.
Vertical circulation is a critical part of any high-rise residential building. While we cannot address all of the issues that are associated with high-rise residential elevator design, I hope we have provided the basis for further thought by design professionals whether designing a new property or relifing an existing building.
As in any high-rise building, the main lobby and the elevator system are essentially the front door of each residence and as such must complement the character of the lobby and market position of the property. The elevator systems should be designed to meet the specific needs of the property with appropriate passenger waiting times and time-to-destination based on the quality and location of the property. The elevator systems are a direct reflection of the quality of the property and must be efficient and reliable. This is particularly true in very exclusive properties where the elevator opens directly into the residence. Properly designed, the elevator systems complement and enhance the asset value of the developer’s or home owner’s property.
Today, high-rise residential elevator systems do not simply provide access for the residents from the main lobby to their respective apartment or condominium. Elevator systems must also address a variety of special needs including, but not limited to; resident security, visitor access, deliveries, discreet penthouse access, resident move-in/move-out, accessibility for mobility impaired, stretcher accommodation, etc. Additionally, in some parts of the world, discreet maid’s access is a cultural expectation that must be considered.
The design period for evaluating the elevator system should be late afternoon/ early evening under a peak five- minute two-way traffic condition. This design period reflects the most demanding traffic condition when residents return home from work and leave for the evening’s activities. The next step in properly designing the elevator systems is to determine the appropriate target performance requirements that the systems(s) must meet based on the location of the property, the type and quality of the property, the number and type of residential units (one-bedroom, two-bedroom, etc.), and the projected number of persons per each type of unit. With these factors in mind, the appropriate average interval and required handling capacity, as a percentage of the theoretical residential population can be determined. This serves as the basis for calculating the number, capacity and speed of the elevators required to meet the target performance requirements of the passenger elevator systems.
High-rise residential buildings are generally provided with onsite parking either at subterranean levels, above ground, or a combination of the two. In any case separate parking elevators from the garage levels to the main lobby provide the first, and best, line of security for residents by requiring a physical transfer between the parking garage elevators and the residential tower elevators. This configuration also improves the efficiency of the tower elevator systems particularly in downtown areas where subways and public transportation are typically used for the office commute as opposed to private automobiles which may only be used on special occasions or on weekend excursions.
Exclusive properties provided with valet parking are often provided with special automobile elevators serving between the ground level and parking levels allowing for high-density parking. There have also been designs considered where the automobile elevators serve the residential floors allowing residents to park on their floors in much the same way as one would park in a conventional single family residence parking garage.
Depending upon the types of amenities provided, separate, dedicated passenger elevators may be required to prevent unwanted access by the public to the residences. This includes health club facilities that are also made available to the public, cafes, and restaurants.
High-rise residential buildings also require dedicated service elevators to accommodate resident move-ins/ move-outs which are accessed via a dedicated serviced vestibule. These elevators are typically provided with front and rear entrances with the front entrance serving the typical floor residential corridor and the rear entrance provided at the dock level allowing for direct loading/unloading of furniture and goods. This elevator is generally the elevator used to meet the stretcher accommodation required by code. It should also be sized large enough to accommodate furnishings up to and including grand pianos particularly in high quality residential properties.
From a building design standpoint, preventing wind noise (stack effect) caused by elevators travelling up through the building is critical and often requires special design considerations. The potential for mechanical and electrical noise and vibration caused by the elevator equipment must also be considered. Proper attention to detail in the design of the hoist machine and controller isolation, often with the assistance of an acoustical consultant, is essential to ensure that all residences are habitable. Machine rooms need to have accessibility without going through penthouse residences.