"We have no other choice but to build sustainably"

Research news - Prof. Werner Lang's objective is constructing residential buildings with a positive ecological footprint. In this interview he explains how this can be achieved and why energy efficiency means much more than just good thermal insulation. How strong is the impact of construction and habitation on the environment? Werner Lang: The construction sector is responsible for approximately 40 percent of CO₂ emissions and energy consumption and for well over half of the refuse produced. Energy consumption and in particular use of materials is enormous in construction. We have to manage these resources more efficiently. Where can we make adjustments in order to reduce negative impacts on the environment? Lang: The first aspect is energy efficiency: Buildings should be built in a way that requires a minimum possible reliance on fossil energies. However, other aspects play an even more decisive role in sustainability, for example the environmental impact of a particular building material or a certain building process.