A room test designed according to the ASTM draft standard was used to investigate the effect of various parameters on the contribution of wall and corner fires to compartment fire growth. Location of the burner (against a wall or in a corner), power program of the gas burner ignition source, and combination of wall linings were varied. An initial series of calibration tests were conducted on ceramic fiber blanket and gypsum board. These tests showed satisfactory instrumentation, good repeatability, and reliable data reduction techniques. The second series were wall and corner tests with Douglas-fir plywood on the walls in contact with the burner and either ceramic fiber or gypsum on the ceiling and remaining walls. Notably, fire growth was much faster in the tests with ceramic fiber. We conclude from the data analysis that at least for corner tests, gypsum board should be used for the ceiling and remaining walls as specified in standardized procedures. A burner program of 40 kW for 5 min followed by 160 kW for the next 5 min was the most informative program; it will be used for wall and corner tests in subsequent steps of this ongoing study.