During the winter of 1931-32 he began construction of the home Houston Architect John F. Staub had designed. With the depression on, good help could be hired inexpensively. From Staub's office, Pratt hired Vance Phenix, a young architect displaced by the lack of projects. Phenix brought along his brother, Dean, a carpenter, and Adolph May, stonemason. Local ranchers Green McCombs and Alfred Lehman helped haul rock to the site and position materials. The cabin is made of only stone and wood. Heart-of-pine rafters, collar beams and sheathing to support the stone roof were shipped in from East Texas. The stone used in building the house was quarried outside the canyon at the base of the Guadalupe Mountains. Always the geologist, Pratt selected 'silty limestones, thin-bedded and closely jointed by clean vertical fractures.' Workers scraped off the thin layer of earth to reveal the proper stones, then using crowbars, levered the blocks apart. The joints made the blocks fit well, and Pratt noted that few required the stonemason's hammer or chisel.