What is believed to be the first use of heavy welded wire fabric mats for reinforcement of flat plate structural concrete floor slabs has scored significant savings in construction time and cost on a New York apartment building. Th flat plate floor system, itself a relatively new design concept, was used of a 12-story and penthouse reinforced concrete luxury apartment. The dual decision to employ flat plate concrete slabs and to reinforce them with heavy fabric rather than conventional bars stemmed from the insistence on obtaining the greatest possible rentable cubic space at lowest cost and the most efficient structural design with speedy erection. Another advantage was its smooth underside without offsets and jogs permitted flexibility of partitioning and cuts plastering and decoration costs. One problem that arose was the speedy erection of the floor system. To combat this problem, Maurice Barron, a consultant was bought in. His suggested reducing the amount of steel and weight per square foot through the use of 24,000 psi design steel stress permitted by fabric's guaranteed yield strength of 56,000 psi and reducing in time and cost of handling of mats as opposed to placing and trying of individual reinforcing bars. The owner believes that the reduction of 15 working days on the project came not only through good planning but also from the use of heavy fabric in the flat plate slab structure.