The purpose of this paper is to investigate generative and evolutionary design models by the new idea of co-evolution. Multi-objective optimization is our main concern. A dynamic co-evolution model is presented with detailed description of its application in eco-conscious housing design. Area and solar constraints of housing design problems are considered with maximum architectural area and solar illumination been optimized. We use dynamic niche models based on a fitness-sharing scheme to define energy and fitness functions for the co-evolution system. Early experimental data are presented and analyzed to show the effectiveness of this approach to evolutionary design optimization and its computational implementation of the algorithms.