A louver assembly for a building wall or the like, including inner blades which are spaced apart to provide longitudinal openings for ventilating the building, and outer blades which confront the longitudinal openings. A strip of wire mesh confronts each longitudinal opening and prevents ingress of extraneous material, such as debris and birds for example. Bracket means connects each outer blade directly to adjacent ones of the inner blades. The bracket means fixes the spacing between adjacent inner blades and the spacing between the inner blades and the outer blades.