Spiral stairs are a very sophistocated structure to design and build, let alone be sure that they meet code. This is an area where, if you have to ask if it can be done, you probably can’t. There are suppliers who offer kits designed to meet your needs and requirements for stairs but have you thought about how you are going to close off and insulate the entrance to the attic? Attics are dry but uninsulated spaces open to outside air. Insulation is usually between the attic floor and the interior room ceiling. If you want to leave an opening to the attic from the house, you have to insulate the roof and have air passages under the roof to remove any condensation–like what a cathedral ceiling has. If you don’t already have this and you plan to leave the top of the stairway open to the attic, you better add a lot of money for new insulation and changing the roof venting.
Henry in MI
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