In general, it is difficult to select a satisfactory product concept because the information in the early stage of design process is subjective, qualitative, and even uncertain to design engineers. The correlations among engineering characteristics for a product concept also increase the complexity of conceptual design. Moreover, it becomes important to consider not only customer requirements but also product lifecycle requirements. In spite of these problems, the resources that can be allocated in the product development are limited so that a company should select the most satisfactory product concept within its available resources. Therefore, it is useful to develop a new method for efficiently supporting conceptual design under this complex design environment. To this end, this study proposes a decision support method with extended house of quality (HOQ). With the proposed method, the best product concept and the associated investment allocation can be decided concurrently under consideration of product lifecycle factors and resource constraints. As a mathematical model combined with the extended HOQ, a mixed integer nonlinear programming model is defined and three heuristic search algorithms are developed. To show the usefulness of the proposed algorithms, a case study and computational experiments are introduced.