When building a home, you need to try to make the most of the space that you have available, especially when building a smaller residence. The average staircase takes up a considerable amount of floor space. However, by considering different styles of staircases, you may be able to come up with a solution that provides you with the access you need without consuming as much space.
Spiral staircases can save more space than any other type of stairs because they consume mostly vertical space. Spiral staircase kits are available in a variety of sizes, but the steeper the stairs and the tighter the spiral, the less space they consume. These stairs are a good option when space is very tight, and are also aesthetically different from what you see in most homes.
Vertical stairs are very steep, and are not much removed from a ladder. These types of stairs are not commonly used in the main areas of a residential space. However, they are useful for access to places such as an attic that doesn't need to be accessed all that often. They might also be used to create access to the upper level of a loft living space in which space is limited.
Stairs With Storage
If you're trying to conserve space, the worst thing you can do is build a staircase where you can't access the area under the stairs. Building a regular staircase is always going to consume a great deal of room. However, by creating a storage space under the stairs, you gain very useful and usable space instead of consuming the entire footprint of the stairs for nothing more than a way to walk between floors.
If you really want to save room in your home, consider a staircase that folds away when not in use. These types of stairs work well for providing access to an upper level or attic. When not in use, they simply fold back into the ceiling, providing full use of the space on the floor below.