The thermal insulation integrity of window and door openings in cavity walls can be increased by using an approach that combines new and traditional methods. <br> <br> The approach is to use two separate lintels, with an L- shaped steel (preferably stainless) providing support of the outer skin and a traditional concrete lintel supporting the inner skin. A polypropylene ready-shaped Type C Cavitray locates onto the Lshaped steel and rises upwardly and across the cavity, providing protection to the entire head of the opening. <br> <br> The tray also extends beyond the opening reveals, to cloak whatever method of reveal closing is deployed. <br> <br> The external masonry is laid onto the Cavitray in the usual manner with Caviweeps in a minimum of two perp joints to provide water evacuation.<br> <br>