You are looking at it as a waste of the floor space it takes up, but it is a critical artery in your house.

If this is going to be the only staircase, make sure not only humans but furniture can make up it these stairs. And that 4 beefy EMTs with a stretcher can carry a 280 lb friend of the family down them.

Ways to multipurpose a staircase: Put it in the center of the house with a skylight over it as a light shaft. Make the skylight openable and you have a whole-house ventilation system.

If space is really tight, have an outside basement access and use the under-stair space for a powder room, and the really short part for pullout storage,

Stairs seem to be a perpetual discussion topic here. Lazygardens has it right, IMO: stairs are much more than utilitarian; they are the only means to access another level of the house for people, goods and services.

If some one in the house is injured or has a physical limitation, the stairs can be a major obstacle unless designed with them in mind. Older folks, with eyesight and/or physical limitations find stairs very challenging. This means that the stairs are a major factor in how a house will be enjoyed (or not) and in reselling the house to another family.

One would not "undersize" a kitchen or other frequently used interior space. What is used more often than stairs?

Good luck on your project.

We looked at this issue in some depth, trying to build a fairly small, 2 story house. We decided to go with the 42" wide--6" has more of an effect in stairs than anywhere else, IMO. Especially for the length you're talking about.

Having grown up with a spiral as the only staircase, these are only reasonable for the main stair if they are quite large (and consequently expensive and/or pretty strange looking).

Thanks for the responses so far.

I should have mentioned that this would be a secondary staircase, near the back. There is a 'main' staircase near the front of the house. This would purely be a utilitarian staircase I suppose.

The larger the staircase, the smaller the kitchen, and I would much rather have a larger kitchen. In fact, I'm pondering not even having a second staircase. However, the house is long and narrow and I'm concerned that this would make for long trips from the master bedroom (located above the kitchen) to the kitchen.

Since you are looking for utilitarian, you definitely don't want small/narrow/spiral!

Do you have room in your master suite for a coffee bar and little mini-fridge? I have seen some in dressing rooms that look nice and how lovely would it be to brew your morning coffee and drink it in bed? I personally would just have one large staircase, rather than a small secondary stair that was hogging space from my kitchen!

I like nini's idea, and we're planning a "coffee bar" in our upstairs sitting room for that reason.

But if it's a second staircase, whatever is the minimal width. Stairs with a landing might make a better layout, at the expense of taking up a tad more space, because they are square.

The SO struggled mightily to get a staircase without a landing in our plans, but he gave up.