Also asked, how do I measure my attic for steps?
Hold the tape measure through the “rough opening,” or open hatch, of the attic at the floor level. The distance from the attic floor to the floor below gives you the measurement for a “disappearing” or non-folding stair.
Keeping this in view, are all attic ladders the same size?
Full-size attic ladders usually need an opening in the ceiling that is at least 22 1/2 x 54 inches. If space is tight, look for compact ladder models designed for closets and other small spaces. Some models need only an 18 x 24-inch opening and require less floor space than standard ladders.
The choice between wood and aluminum isn't easy. They are both very affordable, but wood tends to be less expensive. Both offer a sturdy option, but you cannot get a telescoping attic ladder made out of wood. You can't go wrong with wood or aluminum, but one may fit better for your specific needs than the other.