Precast building construction

A wall tree unit for use in precast building construction in conjunction with one or more base slab units and one or more wall tree units, said wall tree unit comprising:

• a generally planar wall segment having a substantially uniform thickness throughout and including a first end and a second end for forming a wall portion in a building;
• a first generally planar cantilever member integrally joined to said wall segment and extending at right angles from said wall segment while extending the entire lateral width of said wall segment to form a floor or roof portion of a building;
• a second generally planar cantilever member integrally joined to said wall segment, said second cantilever member extending at right angles from said wall segment in a direction opposite that of said first cantilever member while extending the entire lateral width of said wall segment, said second cantilever member being substantially coaxial with said first cantilever member to form another floor or roof portion of a building;
• means formed in an outer edge of each of said first and second cantilever members for matingly receiving a base slab unit;
• an insert formed in a first end of said wall segment;
• a hoisting eye having an opening formed inwardly of said wall segment adjacent a second, opposite end of said wall segment;
• an angle brace connected to said second end of said wall segment in the hoisting eye opening and having a first arm and a second arm, said second arm having an opening;
• and
• a shaft insertable in said insert through said second arm opening for interconnecting two vertically adjacent wall trees with said insert being accessible through said hoisting eye opening.