Abstract: A bore cutting apparatus for polystyrene blocks. Using a plurality of bore forming tubular members, each with its own resistive heating element, a foam block can be bored with a plurality of uniformly sized and shape openings, even openings having a square cross-sectional shape. The foam blocks can then be utilized in a building construction that enables walls to be quickly, inexpensively produced, having structural strengths greater than conventional wood framing methods. The apparatus can also be used for the packaging industry to produce large foam packing materials on a custom basis. The apparatus is fabricated from low cost, easily available materials and is light enough and sufficiently portable to be taken to the job site.