Heroes Building Structures.. how?

Is there a way to allow heroes to build structures? For everything but heroes, in the normal editor, there's a 'Techtree - Structures Built' for the units, but not for heroes..

Easy. You know the items that place structures? the Tiny Altar and stuff? You could make an ability to build each building (with each level giving a stronger building), or just a regular. if you want to copy the building thing exactly, then use a Spell Book ability. Name the Spell Book ability Build Structure and give it the same icon as the normal Build Structure ability... then place all those building abilities inside the Spell Book ability.

Easy.