A Tool for Optimal Refurbishment Design of Low-Energy Buildings

We propose a model that aims to fulfill the following three necessities: the demand for refurbishing the existing built environment, the lack of a reliable means to help architects navigate among the numerous possible solutions for low-energy constructions, and the need for a multi-function tool to analyze buildings as complex systems. We introduce the Optimal Refurbishment Design (ORD) model that is a novel tool to help architects with the refurbishment of an existing building or the design of a new one. The ORD shows four innovative aspects. First, it opens the way to passive building design while focusing on affordable solutions. Second, its core component is based on mathematical optimization. Third, it simultaneously outputs optimal thermal mass and insulation of all the required elements in the building. Fourth, it automatically accounts for the user's needs and local regulations. Unlike most of the approaches in the Literature, the ORD's outputs are not limited by any pre-defined set of materials or strategies. We tested the ORD using a realistic study case of refurbishment, and found that the renovated house achieved the energy consumption of a Passive House by lowering its annual heating/cooling consumption by 23% with a payback period of less than 5 years.