How can you plan for a future elevator in the home you are building today?
Hoistway or Shaft Size - Since you don't know which home elevator or what size cab you may want in the future, if you plan for a large cab now, you leave your options open. The U.S. code allows for residential elevator cabs be up to 15 sq. ft. in size. You may find that someone will want to use a scooter or a wheelchair with leg extensions on it. Don't limit your options by building a shaft that is too small today. You can either use the space reserved for your elevator hoistway as closets or create a cozy reading nook with the front wall left open. Since you may need the elevator to accomodate a wheelchair in the future, it is best to choose a layout that works well for wheelchairs. It is tough to make a 90 degree turn with a wheelchair, so don't choose to layout a hoistway that is shallow and wide. The longer part fo the elevator needs to run from front to back so that you can back in with a wheelchair and then drive out. To have enough room for a wheelchair to do a 90 degree turn, you should really have 42 x 60 inches, which is too large for a home elevator cab by code, so you should never plan for an elevator that has a 90 degree turn in it unless you are not concerned with wheelchair access. The doors should either be stacked on top of each other on all the floors, or be on the opposite end of the cab, so you can drive straight through. The ideal inside shaft or hoistway dimensions for a future elevator from face-of-sheetrock to face-of-sheetrock should be 5 feet wide by 6 feet deep. This is a little bigger than you need if you are planning on elevator with swinging doors, but it is easier to work with extra room than not enough room. One of the side walls should have rail backing installed in it otherwise it can be donw later. Rail backing is wood installed in a specific location where your elevator rails attach to the wall. Every elevator has different backing requirements. The rail backing is typically two sets of two 2 x 12s running from sill plate to top plate the height of the hoistway. Each elevator has a different requirement for where the rail backing should be placed. The rail wall is typically on the same side as the hinges of the door, although some elevators can accomodate the door locks on either side of the door. There should also be a one foot deep pit in the foundation with 12 inches of concrete below that to support your elevator. The concrete floor should be flat and level since your elevator rails will sit on this concrete floor. Our structural engineer calculated that the pit concrete should be 3000 psi with #4 bar crossed at 12" on center. This may be overkill for some elevators, but better too sturdy than to have it crack down the road. Inside your hoistway, you need to have a light, light switch and GFCI outlet, so plan to have those items installed now or at least have power run to the hoistway for them.
Machine Room - Most elevators need a space for the elevator equipment. The controller, which is like the brains of the elevator, needs a place to hang on the wall. The power disconnects which feed the power to the controller will also hang on the wall in the machine room. Each of those items must have at least 36" of clear working space in front of along with a height of 6'8" from the floor to the ceiling for the working space. If you choose a hydraulic elevator, the hydraulic tank will also be sitting in the machine room. The tank cannot intersect into the 36" working space of the controller and disconnect. For more information on equipment clearances, consult the National Electrical Code or your elevator dealer. If you plan for a machine room that is the same size as your hoistway, you will have enough room for whichever type of elevator you choose. The location of a machine room for a hydraulic elevator is ideally on the first floor behind the rail wall. The best place for the machine room for a winding drum elevator is above the elevator in the attic. Some winding drum elevators will have the cable drum mounted in the attic space. You should also have 6'8" head room in the attic area above your hoistway. In your machine room, you should also have a light, light switch and GFCI outlet. Even if your state does not currently require the inspection of residential elevators, your local codes may change in the future, so it is best to plan for everything to be installed to the national codes. Some states will allow you to obtain the 36" clearance by installing doors that open to leave the entire working space clear as in the photo below. Not all areas allow this configuration.
Door Openings - Doors are not centered on an elevator shaft. They are always slightly to the left or right of center, depending where your rail wall is. If you have your contractor span the central 4 feet of your 5 foot openings with a header, you will have room to move the 3 foot wide door around once you choose your elevator in the future.
Power - Some elevators require only a 110 volt 20 amp circuit and others need a 220 volt 30 amp circuit in addition a separate 110 volt 20 amp circuit. If you bring both over to the elevator shaft, and more specifically to the assigned machine space, you can decide later which elevator you would like. You will also need a phone line connected to your house line brought over to the shaft area. Some elevators require power at the lowest floor and others at the top of the shaft, so just terminate your power in a junction box where it can be made to go to either location.
Exceptions- The higher end elevators will actually be on commercial systems and have different requirements. If you are considering a heavy duty elevator of 1400 lbs. for heavy cab materials such as stone flooring, a high-end custom cab or a commercial grade elevator with sliding doors, you should proceed with the elevator installation at the time you build your home due to increased pit depth, rail backing requirements, overhead and power requirements and the difficulty of getting the large pieces into the house. Otherwise, you may alternately choose to leave a space on the exterior of your home where a hoistway may be built in the future. Leave a 6 foot wide space between windows and doors on all floors of the home where doors could be cut in later. Make sure there are no electrical, plumbing or HVAC lines in this section of the wall. Also make sure the air conditioners and power panels do not enter the house in the area you are reserving.
Planning for an elevator in your home can save you around $30,000 compared to what it costs to cut up your house in the future. Every house being built should have an elevator space planned into it. The construction costs to prepare for an elevator are just a fraction of what it costs later and you can really enjoy the extra closet space by installing floors in the hoistway at each landing. Even just having prepared your home for an elevator is a selling point and can help your home sell before your neighbors home!