Building from the bottom up sounds like erecting to me.
![whistle:](https://www.virtual-pub.com/SMF/Smileys/default/whistling.gif)
Quite so Uncle...
e·rect (-rkt)
adj.
1. Being in a vertical, upright position: an erect lily stalk; an erect posture.
2. Being in a stiff, rigid physiological condition.
3. Archaic Wide-awake; alert.
tr.v. e·rect·ed, e·rect·ing, e·rects
1. To construct by assembling: erect a skyscraper.
2. To raise to a rigid or upright condition.
3. To fix in an upright position.
4. To set up; establish: erect a dynasty.
5. Mathematics To construct (a perpendicular, for example) from or on a given base.