Create a square block extrusion in sculpt? Newbie here. I am new to Blender, I am wondering is it possible(in sculpting mode), to model a square indent into the object.

Say I have a cylinder or a cube, and I want to extrude a small square region on  one of its surface(you can imagine this to be a building). It has a square window, and the window is slightly out of the building's wall plane. I hope to repeat this effect for every surface, and each surface will have three by three windows. I don't need the window to have perfectly sharp corners. It could be slightly rounded. Thanks for the guidance.
You can use multiple tools to achieve the effect, but I think the easiest is to use a stencil mapped texture with the shape of the window and a Layer brush. The height of the layer brush determines the depth of the effect. For best results, the sculpt plane should be "Area Plane" locked (ticking the lock icon next to the drop down menu).

Here is a rough picture with the settings: