This study aims at figuring the roof snow loads to prevent accidents associated with roof snow removal or to reduce the risk of snow-load induced roof collapses. A heat, ice, water and air balance model, i.e. a Roof Snow Load (RSL) model was developed to calculate the roof snow load and the validity of the RSL model was examined by comparing field test results with the computational ones. Consequently, the RSL model successfully reproduced the time changes in the snow height, snow density, volumetric water content and the roof snow load.<br>Additionally, effects of the heat across the roof (house heat) on the roof snow load were evaluated by numerical simulations using the RSL model. It was found that a coefficient involved in the roof snow load reduction (a snow melt coefficient) decreases exponentially with increasing in the house heat flux.