Research projects are (co)financed by the Slovenian Research and Innovation Agency

• Member of the University of Ljubljana: Faculty of Mechanical Engineering
• Project code: L7-4495
• Science: Interdisciplinary research
• SICRIS: Living Walls for Future Sustainable Buildings and Cities

Co-funding organisation: KNAUF INSULATION d.o.o., Škofja Loka

Project Description

Living Walls for Sustainable Buildings and Cities of the Future

The project is based on interconnected research on energy efficiency and the sustainable use of water resources and nutrients in living walls. It focuses on areas that have not yet been sufficiently and comprehensively researched. The goal of the project is to position living walls among sustainable, energy-efficient, and cost-effective technologies.

Traditionally, the building envelope is a static element that strongly separates the potential of the outdoor and indoor environments, thereby limiting further reductions in building energy use. Within the profession, the building envelope is recognized as a key element for achieving the energy and climate targets set by the EU. In recent years, research and development have increasingly focused on multifunctional and adaptive building envelope components, including vegetated building elements. These make it possible to better utilize the energy potential of the environment, significantly improve the energy efficiency of buildings, and at the same time enhance indoor comfort and the quality of the urban environment.

However, for living walls—which are still a relatively new technology—there is a significant gap between conceptual design, actual operation, and a comprehensive understanding and evaluation of energy and material flows, as well as their impacts on urban and indoor environments. For example, living walls are often irrigated with potable water supplemented with fertilizers, which increases their environmental footprint.

The aim of the project is to develop an energy- and environmentally efficient living wall system with multifunctional properties: the ability to use and/or treat alternative sources of water and nutrients (e.g., greywater), and enhanced air cooling in the air cavity behind the living wall for energy-efficient building ventilation. Through measurements in real environments, the thermal response of living walls will be investigated under both typical and extreme boundary conditions, which may contribute either to reducing building energy use or to enhancing the multifunctional performance of living walls.

The final objective is to develop and validate a detailed mathematical model of the thermal and hydrological response of living walls. This model will represent an important contribution to the wider scientific community and will serve as a basis for further research, development, and software tools for design. The project will also investigate the potential and feasibility of using alternative water and nutrient sources for irrigation and fertilization—such as greywater from buildings and rainwater—with the aim of reducing or eliminating the use of potable water and mineral fertilizers.

In addition, a system for greywater heat recovery supported by a micro heat pump will be designed and analysed. The potential of living walls as treatment systems for greywater will also be investigated, enabling its reuse within buildings. Efficient and sustainable irrigation algorithms based on weather forecasts, developed within the project, will be essential for achieving optimal living wall performance.

Research and development of living walls with lightweight mineral wool substrates will enable the project co-funder, Knauf Insulation d.o.o., and its affiliated companies to expand their portfolio with integrated solutions for green infrastructure in sustainable buildings and modern urban districts, while also reducing the environmental footprint of existing products. The reliable multifunctional living wall systems and sustainable irrigation and fertilization solutions developed within the project—and implemented in production—will provide the company with a significant competitive advantage in the global market. In this context, validated results of thermal and hydrological performance analyses, the potential of greywater for irrigation and heat recovery, and environmental impact assessments based on numerical and multi-parameter empirical models developed within the project will play an important role in design, consulting, and marketing activities.

Project co-funding:
Slovenian Research and Innovation Agency (ARIS); Knauf Insulation d.o.o., Škofja Loka

Participating ROs:
University of Ljubljana, Faculty of Mechanical Engineering (Laboratories LOTZ and LAHDE)
University of Ljubljana, Faculty of Civil and Geodetic Engineering
University of Ljubljana, Faculty of Health Sciences