An improved panelized construction system for providing a wall formation for attaching to a foundation wall including a plurality of block forming units adaptable for being both vertically and horizontally arranged to form the wall formation, the opposed side wall portions of each unit including cooperatively engageable portions for fixedly attaching the units in side-by-side horizontal relationship. The present methods for attaching the assembled wall formation to at least a portion of a foundation wall includes providing a plurality of adjustment mechanisms for enabling the wall formation to be leveled and aligned with adjacent wall formations or other structures independent of any foundation misalignments, and providing a plurality of foundation cavities adjacent the upper edge portion of the foundation wall for receiving corresponding foot members associated with the wall formation for encapsulation in a cement slurry.