Refers to earlier work by Mattingly, Peters, Harrje and Heisler which indicated the possibility of reducing air infiltration by using sheltering devices such as fences, neighbouring buildings and trees. Reports use of wind tunnel air infiltration model to explore the effect of trees in a windbreak on a model home. Presents results of tests determining the effect on wind-induced air infiltration of the variation of various windbreak layout parameters. Introduces concept of turbulence generation as the mechanism of tree wind sheltering. Concludes that windbreaks are an economically viable method of reducing home energy consumption. Gives method for predicting monetary savings due to planting of a windbreak and an example of its use.