With the increasing environmental sophistication of consumers, there is a need to consider environmental factors and sustainability in the design process. This paper proposes a design methodology intended for software implementation called eAD+ to address the following four issues: 1) there are inherent couplings between eco-factors and product design parameters, 2) eco-factors are seldom structured for ready use within all phases of the design process, 3) there is a need for a formal feedback mechanism from the results of eco-analysis to the design process, and 4) it can be difficult to identify which design choice causes the most egregious environmental issue or functional coupling. eAD+ is based primarily on the Axiomatic Design (AD) methodology and addresses these issues as follows. First, AD directly identifies couplings between the functional requirements (FRs) in a design so that efforts, such as TRIZ, can be applied to address them. Second, as common eco-factors do not provide sufficient structure for inclusion in the AD framework, we develop structured eco-FRs and constraints. These are included alongside the product FRs throughout the design process. Third, the subset of the design matrix (DM) relating the eco-FRs to the design parameters explicitly incorporates feedback from eco-analysis into the design process. Here a database containing environmental (or sustainability) information is employed to evaluate the design. Fourth, we employ an augmented DM (drawing inspiration from the House of Quality of QFD) that provides weights highlighting which design parameter has the greatest influence on eco-factors and functional couplings.