This paper describes an approach to integrating functional and non-functional design verification for embedded control software. The method uses functional models, which have traditionally been used in functional verification processes, to drive non-functional verification also. This is achieved by defining strategies for extracting non-functional models, which contain structural and quantitative information about nonfunctional characteristics such as performance and modifiability, from functional ones. Non-functional verification tools may then be used on the resulting models to check that desired non-functional properties, such as ease of modification, are catered for in the design. An extended example involving the analysis of a model for modifiability is presented, as is tool support for extracting non-functional models from functional ones.