Towards the technical development of the prefabricated multifunctional façade

One of the main objectives of 4RinEU project is to develop robust technologies in order to improve the deep renovation strategies for existing buildings. Following this purpose, the backbone of the technologies is the technical prefabricated timber based multifunctional façade, whose development is coordinated by Gumpp & Maier with the scientific support of Eurac Research.

On the one hand, the technological development aims to find solutions able to reduce maintenance and operation costs over time, construction site duration and disturbance for the occupants in comparison with a traditional retrofit approach. On the other hand, the scope is to enhance the construction works quality and durability, as well as the overall building performance.
Prefabricated façade panels can have different size and level of industrialization, including a combination of the following elements: new windows, ventilation machine with heat recovery system, natural ventilation openings, renewable energy technologies, energy distribution systems, shading devices, thus a guideline for integrating elements is needed.

During the first six months, Eurac Research and Gumpp & Maier focused the analysis on existing technologies and market products to assess their potential for integration into prefabricated façade modules with reduced costs.
Products have been categorized in insulation materials, mechanical ventilation units, air and water distribution systems and energy generation technologies (solar thermal collectors and photovoltaic modules).

Another key result of the first six month is CLEAR-IN (Computing Lifetime Economic Aspects of Retrofit Investments), a technical-economic evaluation tool for assessing the business model of deep renovation technologies. It allows evaluating the Life Cycle Cost considering the effect of design choices related to building envelope and energy system and the influence of the performance uncertainties on the results.
The strength of the tool is multidisciplinary-based approach that enables the user to define several inputs such as technical features, maintenance recurrence and cost, energy efficiency, and financial aspects. This allows the user to quantify the payback time of the solutions, with a special focus on prefabricated elements, as well as the initial investment cost.

These two preliminary results represent the ground needed to define the first façade concepts, with a special focus on the renovation needs of the three 4RinEU Demo-Cases.
In particular, 4RinEU will promote the following concepts for the integration:

• Technical shaft façade module on the external side for building integrated services
• Heating pipes distribution into façade + Solar Thermal technology on roof
• Decentralized mechanical ventilation into façade
• Passive façade modules
• Air Ducting system integrated into façade + centralized mechanical ventilation
• Photovoltaic technology integrated into façade

The next objective for Eurac Research and Gumpp & Maier is the definition of a set of technical sheets for the façade concepts with all the indications for the design and production of prefabricated timber based elements. A special focus will be devoted on supporting the building owners (Boligbygg, Woonzorg and AHC) and the technical partners (SINTEF, Trecodome and AIGUASOL) to write the technical specifications needed to assign a designer and a construction company.

The selected façade concepts will be further developed towards the construction of a mock-up to be tested in Eurac Research labs before the end of the year.