Simulation-based energy efficiency retrofit of listed building ensembles: An alternative solution with a climate envelope

This article draws an innovative architectural solution for enhanced energy efficiency by retrofitting ensembles of listed buildings. A combination of various simulation tools and a self-developed feasibility tool has been used at the preliminary design stage to develop a measure at an urban scale within the campus of TU Berlin.

First, a potential analysis for 48 buildings within the campus has been run using multi-zone simulations with Modelica. Afterward, with the feasibility analysis tool based on Python, called HCBC-Tool, all possible measures have been ranked at the pre-stage of this project. As a conclusion, by buildings where standard measures are not feasible, alternative solutions have been developed using DesignBuilder, where not only energy-related issues both also architectural ones were considered. Additionally, energy substitution measures have been simulated with SunnyDesign to complete the concept. Here, a "climate envelope (CE)", which is an additional transparent envelope covering the buildings partially, has been developed for a building ensemble built between 1883-1975. Enhancing the energy efficiency of all five buildings within the ensemble with standard measures up to the new building level according to the German energy efficiency regulations would reduce their energy consumption app. 32%. Nevertheless, this regulation is not mandatory by listed buildings. Besides, 12,152 m² external envelope surface should be retrofitted. By comparison, a CE could lead to enhanced energy efficiency and it alone could reduce the energy demand of the building ensemble up to 33% and combining it with standard measures could increase the savings up to 60%. (paper)