The structuring of air source heat pumps’ prices in a retrofitting residential buildings market: what did I pay for?

摘要

The recent European energy proposals for the revision of the Energy Efficiency and the Energy Performance of Buildings Directives emphasize the importance to drive investments into the renovation of building stocks and to stimulate the refurbishment demand. Moreover, the challenge of acquiring data about retrofitting is reasserted because the lack of reliable data is detrimental to the perception of cost-effectiveness. Especially it is well known that refurbishment prices are, according to various papers, subject to large uncertainty and can sometimes be controversial even if public subsidies are available.In this paper, we evaluate the main determinants of prices. Their structuring is a complex phenomenon blending technical, economical and organizational sides. For such purpose, we analyzed hundreds of invoices concerning the installation of heat pumps in existing buildings.In order to model the influence of the different variables on the up-front cost paid by the households, we developed general linear statistical models (ANCOVA) blending qualitative and quantitative variables. The variables taken into account are:1. Technical: living area, type of building (multi or single family), coefficient of performance, installed power;2. and economic: company description (number of employees, main activity and sales network), average household’s income linked to location, brand of equipment installed.Our results confirm the importance of economic variables (such as brand or sales network) beside the technical variables in the explanation of prices. Our results also quantify the relative role of each variable. Half of the prices’ variation is explained by the models and it is a huge step in the understanding of retrofit prices in order to better orientate the public subsidies.