Variable performance building cladding according to view angle

Abstract

This invention relates to inclined outer building surfaces such as roofs reflectively responsive to sun elevation angle and predominantly ornamental when viewed from common viewing positions. More specifically, this invention relates to methods of sizing, shaping, surface characteristics, and coating resulting in improved performance, increased ornamental quality, improved economy of roofing of this class using human eye contrast sensitivity and visual perception.

1 . An aesthetically pleasing slanted roof reflectively responsive to sun elevation angle, comprising;
 a repeating set of surfaces, portions of which are oriented predominantly toward the sun and portions of which are oriented predominantly toward observers at common viewing positions; and,   treatments applied to the surfaces, comprising;
 at least one surface treatment that is selected for emissivity and reflectivity properties in the direct sunlight direction; and, 
 at least one surface treatment that is selected for aesthetically pleasing visual properties in the observer viewing direction, wherein; 
 the surface treatments are selected and applied to reduce visual perception of the repeating set of surfaces. 
   
     
     
         2 . The roof of  claim 1  wherein at least a portion of the surface treatments are smoothly varied between regions of high contrast differential. 
     
     
         3 . The roof of  claim 1  wherein surface treatments are selected to reduce visible contrast amplitude. 
     
     
         4 . The roof of  claim 3  wherein at least one surface treatment selectively reflects non-visible sunlight in the direct sunlight direction. 
     
     
         5 . The roof of  claim 1  wherein the surfaces are textured to increase visible spatial frequency. 
     
     
         6 . The roof of  claim 1  wherein at least a portion of the surface treatments are applied in a visible pattern. 
     
     
         7 . The roof of  claim 1  wherein surface treatments are applied at the location of use. 
     
     
         8 . The roof of  claim 3  wherein the contrast reduction includes at least one of;
 applying the treatments to the sun facing and observer facing areas in analogous colors, 
 applying the treatments to the sun facing and observer facing areas with small luminance differential, 
 sizing the treatments with dimensions below the spatial resolution of observers at common viewing positions; and, 
 applying the treatments with smoothly varying gradients between the sun facing and observer facing areas.