Traction (MRL). Also known as machine room-less (MR) elevators, these are run by counterweights. Rather than have a separate room for the mechanism, it is housed at the top of the elevator so it doesn't take up much space. This is a good option when retrofitting an existing home.
Pneumatic. This type of elevator runs on air pressure by way of polycarbonate tubes -- think the human version of what you see at the bank drive-through window. Because there is no separate mechanism, these lifts don't require space to store it. This makes this type good for existing homes.
Hydraulic. This type of elevator is operated by a piston within a cylinder. There is no machine room; rather, the controller is housed in a cabinet installed on a nearby wall.
Cable-driven. This type of elevator is similar to what you ride in a building. It consists of a shaft and car that's lowered and raised by counterweights. The mechanisms may require a separate room, making this elevator require a lot of room and therefore better for new construction.
Chain-driven. This is similar to cable-driven elevators, but instead of a counterweight, there is a chain wound around a drum. The chains are even stronger than cables and don't require the extra space to store the mechanism.
The right type of elevator depends on the size of the home and whether it's an existing structure or new construction. While there are elevator options that can be retrofitted, you have the most options with a custom build. If you're building a home and don't want to commit to an elevator's cost now, you could include the space for the future elevator shaft that could instead be used as a closet or other utility space in the meantime. While the future owner will have to foot the bill of installing the elevator, they will have far less trouble with remodeling.
What is the value of installing a home elevator?
According to RetirementLiving.com, a home elevator can add to the property value by 10% or more. The personal value, however, is priceless, as an elevator allows the homeowner to age in place. The term "forever home" is often a wistful goal, but with an elevator, remaining in one's home for life is an actual possibility.
The bottom line
If you're building new construction, you should certainly consider adding an elevator for the value it brings -- even though that value requires a hefty budget. However, if you're looking to renovate an existing home, you should weigh not only the costs but the logistics of retrofitting a space with an elevator. While it would add value to the property, it might not be worth the hassle to add it to an existing home.