A method of creating a sleeveless passage of controlled size and shape through a concrete (41) wall poured in a form including two form plates mounted in fixed, spaced relation separated by a width W comprises first forming a plurality of modular passage units (20), each unit including an annular main shell (22) of external size and shape conforming to a segment of the sleeveless passage; each unit has end closure walls (23) closing the ends of the main shell (22). Each modular unit (20) has an axial length L1; W>L1. A first modular unit (20A) is mounted on the inside of one form plate (31) at the location selected for the passage through the wall, with one of its closure walls (23) engaging the form plate (31). At least one additional modular unit (20B,20C) is mounted on the first unit (20A) to form a modular unit stack having a total length equal to the width W, with at least one closure wall (23) remaining in the center of the stack. The other form plate (31) is mounted against an outer closure wall (23) of the last modular unit (20) in the stack.
The invention further embraces plural forms of modular passage units utilized in the foregoing method.