The pilot survey of selected buildings in the region of study established the average window-to-floor ratio to be 54%.
To assess the effect of thermal mass, three models were used, one with each of the three different thermal masses: solid sandcrete blocks (SSB), baked bricks (BB), and concrete (CONC) all with window-to-floor ratio of 54% as in Table 1.
Reduced window-to-floor ratio for all the envelope materials tested leads to reduction in peak indoor air temperature for all the thermal masses (Table 4).
Amongst all the thermal masses, as the north and south window-to-floor ratio increases, the TDR decreases.
In La Roche and Milne  study, when the south window-to-floor ratio was of a minimum of 11% and above, the indoor air conditions in the control cell, with a fixed infiltration rate, were higher (worse) than that of the average outside air temperature.
In all the above, TDR is a temperature difference ratio; WFR is window-to-floor ratio (north and south window).
For all the expressions, as window-to-floor ratio increased, the temperature difference ratio decreased.
Test Description model Model 1 Light-weight mass with 0.54% window-to-floor ratio Model 2 Light-weight mass with 0.27% window-to-floor ratio Model 3 Light-weight mass with no window Model 4 Light-weight mass with 0.54% window-to-floor ratio Model 5 Light-weight mass with 0.27% window-to-floor ratio Model 6 Light-weight mass with no window Model 7 Heavy-weight mass with 0.54% window-to-floor ratio Model 8 Heavy-weight mass with 0.27% window-to-floor ratio Model 9 Heavy-weight mass with no window TABLE 3: Outdoor and indoor air temperatures of model 9 and the control model.