Arno Schlüter

Application of clustering for the development of retrofit strategies for large building stocks

Abstract In order to reduce energy consumption and emissions from the built environment, it is vital to transform the existing building stock and develop retrofit strategies to achieve energy efficiency and building-integrated renewable energy supply. Compared to developing cost-optimal retrofit strategies for one building, the development of strategies for 100 to up to 10,000 buildings remains a major challenge. This paper presents a method to cluster buildings based on their sensitivity to different retrofit measures, focusing on the cost-effectiveness. Derived from algorithmic clustering and combined with time and cost data, a tailored development of retrofit strategies for large building stocks becomes possible. Improved identification of retrofit measures and strategies, in contrast to the conventional classification based on building type and age, is demonstrated. The method is illustrated, using the data from the case study project ‘Zernez Energia 2020’, which aims to achieve carbon neutrality of a Swiss alpine village.

Exploring Urban Space Volumetric Site Analysis for Conceptual Design in the Urban Context

This paper proposes a set of new analytic and visualization methods for conceptual design in the urban context. The methodology is based on the discretization of the urban site into a volumetric grid of points. For each of these points, different physical properties such as solar radiation, airflow, and visibility are computed. Subsequently interactive visualization techniques allow the observation of the site at a volumetric, directional and dynamic level, making visible information that is typically invisible. Several case-studies demonstrate how this allows to generate suggestions, for example, for the definition of the form of a building or for the rationalization of its surfaces. This approach aims at developing a conceptual design process that allows the fusion of active technologies, passive methods, and expressive aspects, in cohesive concepts able to embrace and exploit the diversities of an urban site.