Abstract: A method for constructing a multistory building comprising: constructing finished modules having a concrete base and vertical sidewalls; placing a first series of such modules at a single horizontal level such that at least one sidewall of each such module is spaced by a distance of from about 2 to about 12 inches from and is parallel to the sidewall of another such module; pouring and hardening concrete to fill at least a portion of the space between such sidewalls from the base to the top of such sidewalls to form supporting concrete walls; placing another additional series of such modules on the tops of the supporting concrete walls in the spaced relationship previously described and filling the spaces to form additional supporting concrete walls; and repeating the procedure previously described until the desired number of levels of modules is obtained.