Wall of Iron

This spell can help in construction, especially if you need a wall in place right away to help seal off an area. Remember that wall of iron only creates flat, featureless vertical walls. Even if you used wall of iron spells to construct a room, you would have to fasten them together yourself and cut out doors and windows.

The typical casting (by a 9th-level caster) gives you a 225-square-foot wall, 2 inches thick. Alternatively, you can halve the thickness (to 1 inch) and double the area (to 450 square feet). The DC for a Strength check to break it is either 27 (for a 1-inch-thick wall) or 29 (for a 2-inch-thick wall).

You can only conjure a wall of iron as a flat plane, although the edges do not have to be square.

Casting: 500 gp (Wiz9) or 550 gp (Sor10)