Lower Object count on parcel

How would i do this? Like lowering the amount of prims/ building box in a house?

Well, the obvious answer is just keep pressing delete.

Seriously though, as you get better at building, you'll discover all kinds of tricks to prim efficiency. For example, you can use a hollowed half cube to make 2 corner walls instead of using 2 seperate cubes. You can use an advanced cut tube to make a cylinder with a cone on top instead of using 2 seperate cylinders. You can use a single cube with the corner cut away to make a chair instead of using two or three seperate prims. You can cut the prim count of stairs in half by using cut cubes to do steps per prim instead of uncut ones for one step per prim. You can eliminate steps altogether and just use ramps for huge savings. The list goes on and on.