Journal of Facade Design and Engineering

Multifunctional façades for renovation through industrialization

Maria Founti, Stefano Avesani, Peru Elguezabal — Sat, 23 Dec 2023 00:00:00 +0100

This Special Issue compiles results of EU H2020 funded projects working on the development of multi-functional envelope solutions for deep renovation of buildings. The projects have a common and aligned objective to develop and demonstrate plug & build smart components, including insulation materials, heating and cooling elements, ventilation, smart windows, energy production, solar harvesting, and storage with necessary connecting and controlling parts to be integrated in a prefabricated envelope system. They highlight that plug & build solutions are suitable for mass production by industry for buildings undergoing deep renovation to NZEB standards. They also underline that the development and implementation of digital based technologies can boost the application of such industrialized concepts.

Definition and design of a prefabricated and modular façade system to incorporate solar harvesting technologies

Sat, 23 Dec 2023 00:00:00 +0100

The current research presents the design and development of a prefabricated modular façade solution for renovating residential buildings. The system is conceived as an industrialised solution that incorporates solar harvesting technologies, contributing to reducing energy consumption by employing an “active façade” concept.

One of the main challenges was to achieve a highly flexible solution both in terms of geometry and enabling the incorporation of different solar-capturing devices (photovoltaic, thermal, and hybrid). Therefore, to be able to provide alternative customised configurations that can be fitted to various building renovation scenarios. Guided by the requirements and specifications, the design was defined after an iterative process, concluding with a final system design validated and adopted as viable for the intended purpose.

A dimensional study for interconnecting all the technologies composing the system was carried out. Potential alternative configurations were assessed under the modularity and versatility perspective, resulting in a set of alternative combinations that better fit the established requirements. Complementarily, the system also integrates an active window solution a component that incorporates an autonomous energy recovery system through ventilation.

The main outcome is explicated in a highly versatile modular façade system, which gives existing buildings the possibility to achieve Nearly Zero Energy Building requirements.

SmartWall

Sat, 23 Dec 2023 00:00:00 +0100

Following the need of urban areas to maintain the existing building stock and simultaneously upgrade the overall energy performance, the renovation down-to-nZEB state has already become a necessity. In this regard, a vast range of prefabricated solutions have been developed lately. The main objective of such solutions would be not only to constitute an effective system to tackle building energy consumption but also to be versatile in terms of implementation and economic viability. In this regard, an adaptable off-site prefabricated envelope solution with an embodied HVAC system called “SmartWall” has been developed. The SmartWall can minimise thermal losses through the well-insulated envelope while, at the same time, its integrated HVAC system efficiently maintains indoor thermal comfort conditions. This study examines the virtual implementation of the SmartWall as a “Plug-n-Play” renovation solution to reach the nZEB state of a typical apartment in a multi-family residence in Athens. The analysis considers two SmartWall alternatives using conventional and eco-friendly materials. The results indicate a reduction of 88% in primary energy consumption without affecting thermal comfort conditions and highlighting that the nZEB state can be ensured if the SmartWall application is enhanced with photovoltaic modules.

Plasmochromic Modules for Smart Windows

Mirco Riganti, Julia Olivé, Francesco Isaia, Michele Manca — Sat, 23 Dec 2023 00:00:00 +0100

Active glazing components, which can dynamically regulate incoming solar radiation, are particularly interesting, as they simultaneously impact multiple aspects, such as thermal and visual comfort and overall energy consumption. Near-infrared EC windows (also referred to as “plasmochromic”) enable selective spectral control of the incoming solar radiation and efficiently respond to ever-changing lighting, heating and cooling requirements. They allow to selectively filter a large amount of near-infrared solar radiation passing through the window, thus blocking solar heat gain during hot summer days and letting it permeate over sunny winter days whilst independently regulating the amount of daylight.

This article delves into the core attributes of such glazing systems, showcasing recent advancements in their design and fabrication. By evaluating key metrics like luminous transmittance (T_LUM), solar transmittance (T_SOL), and total solar heat gain coefficient (g-value), the paper presents a preliminary performance assessment of smart glazing employing this technology. Furthermore, the authors prospect the importance of implementing appropriate control strategies for these systems to fully exploit their potential in reducing energy consumption while maximising comfort.

Implementation of a multifunctional Plug-and-Play façade using a set-based design approach

David Masip, Grazia Marrone, Irene Rafols Ribas — Sat, 23 Dec 2023 00:00:00 +0100

An immediate paradigm shift is needed to transform the deep renovation market for improved building performance and expanded energy efficiency horizons. The financial, social, and sustainability challenges of the EU targets suggest research towards reliable, inter-compatible, and interoperable solutions aiming at combining different energy conservation measures. This work proposes the implementation of a lightweight Plug-and-Play (PnP) building system for façade renovation using a set-based design approach. The PnP module, based on a main structure in the form of a Light Steel Frame (LSF) and a metal-faced sandwich panel, is combined with various market-ready components. The efficient integration of these third-party products is highlighted by defining and demonstrating the design process, implementing a solution driven by the reach of a highly industrialised solution, easy to assemble and install, customizable, scalable, and adaptable to the existing buildings. With the set-based design matrix, different integration scenarios are investigated through virtual prototypes. Moreover, to facilitate the shift from design to construction of the integrated PnP module, the study proposes three prototyping levels to demonstrate the efficiency of the design integration methodology and the technical feasibility of both the various module's configurations and the overall module, exploring them through the realisation of preliminary, full-scale façade and actual environment-applied prototypes.

Off-site prefabricated hybrid façade systems

Sat, 23 Dec 2023 00:00:00 +0100

The residential sector is responsible for the largest share of global energy consumption, while the existing building stock in Europe is relatively old. This issue, in combination with the low rate of new constructions, highlights the necessity for deep renovation of existing buildings to reach NZEB standards. At the same time, in the last decades, off-site prefabricated solutions have gained popularity in the building market, allowing the reliable and effective integration of diverse components and reducing the total renovation cost and occupants’ disturbance. The current study describes three all-in-one “Plug & Play” prefab renovation solutions and their assessment in terms of thermal, static, acoustic, and fire performance. The assessing performance is selected depending on their incorporated element as well as the national regulations of the country where the renovation solution is going to be installed. The assessment aims to ensure their characteristics’ satisfaction with the European and national requirements. In parallel, the assessment identifies the accurate behaviour of prefab façade systems both in passive and active mode and improves/optimises any possible design drawbacks.

Automation process in data collection for representing façades in building models as part of the renovation process

Kepa Iturralde, Asier Mediavilla, Peru Elguezabal — Sat, 23 Dec 2023 00:00:00 +0100

A key barrier in building-facade renovation processes is that, contrary to new designs, an initial building model where the design process is based rarely exists, and the technologies usually employed to create it (e.g., based on point cloud scanning) are costly or require modeling skills. This situation is a clear limitation, especially in early decision stages, where the level of detail required is not very high, and the analysis and studies to consider the renovation plan (e.g., simplified energy simulations and renovation potential, or estimation of the number, types, and dimensions of the prefabricated modules incorporating solar panels) highly depend on such digital models. This paper introduces a process that, based on freely available data such as open GIS sources (local Cadasters, OpenStreetMap…) and façade images, can semi-automatically generate the 3D building model of the existing conditions, and in a second step also suggests the prefabricated facades module layout for building upgrades. Additionally, no onsite visit is needed. When the upgrade is focused on the façade, a big opportunity is identified for generating the building model and a realistic representation of its envelope, only using online data sources as input. The process developed consists of a set of easy-to-use software tools that can be used independently or combined in a workflow, depending on the available data and starting conditions. Time saving is very clear and costs can be reduced.

Comparative cost analysis of traditional and industrialised deep retrofit scenarios for a residential building

Sat, 23 Dec 2023 00:00:00 +0100

In this paper, the economic competitiveness for deep retrofit actions between the industrialised off-site and the traditional on-site approaches are discussed by using a comparative Life Cycle Costing (LCC) analysis. This assessment was based on a deep analysis of all renovation-related cost and timing processes, from design to operation and maintenance phases. The study was based on three retrofit scenarios for an existing building in Italy undergoing a deep renovation. The Life Cycle Inventory (LCI) was developed starting from real costs and a list of bills collected by the design team and the industrialised technologies developers. Afterwards, the LCC modelling was performed for all scenarios. The results show that the two deep retrofit approaches (traditional and industrialised) are comparable in terms of investment costs, even if a gap of around -7% and +16% still exists. This highlights a potential for technological optimisation. Moreover, the operation and maintenance phase has shown to be key to transforming the expected higher quality of the industrialised components into a prolonged life expectance, hence highly impacting the whole cumulated Net Present Value. Finally, the analysis of the End of Life (EoL) phase in case of possible reusing of some dismantled components in the industrialised scenario resulted in contributing in a relevant way to increase the final value of such an approach.

Assessing the circular re-design of prefabricated building envelope elements for carbon neutral renovation

Ivar Bergmans, Silu Bhochhibhoya, John van Oorschot — Sat, 23 Dec 2023 00:00:00 +0100

Buildings and the construction industry at large are significant contributors to the catastrophic climate breakdown. The built environment is responsible for 37% of the total global carbon emission, of which about a third arises from the energy used to produce building and construction materials, usually referred to as embodied carbon. One of the key strategies to reduce the environmental impact of buildings is to significantly improve their energy efficiency, which is referred to as deep renovation. Prefabricated building envelope elements intended to prevent heat loss through the building envelope are considered a key deep-renovation technology. Connecting prefabricated elements to a building reflects a potential stream of waste if applied linearly with severe negative environmental impact in terms of natural resource depletion and exposure to pollutants. This article reports on a quantitative Design for Disassembly (Dfd) indicator to assess future recovery potential and, subsequently, its impact on embodied carbon emission of the circular redesign of three different prefabricated building envelope elements. Although none of the redesigned elements are yet considered 100% circular, the development of these three prefabricated building envelope elements showcases that the environmental impact can be substantially reduced following a well-structured and dedicated innovation process. The reduction of the environmental impact is indicated by lower quantities of embodied carbon up to 50% and an improved design for disassembly, reflecting a higher reuse potential of building materials and components. Several limitations and directions for further research were identified to advance the development of circular, prefabricated deep-renovation building envelope elements.

Energy-saving potential of thermochromic coatings in transparent building envelope components

Matthias Fahland, Jolanta Szelwicka, Wiebke Langgemach — Sat, 23 Dec 2023 00:00:00 +0100

Advances in the energy management of buildings are essential for reducing the carbon footprint in the building sector. Applying special window coatings of varying optical properties offers new chances for improved energy efficiency. Thermochromic vanadium oxide (VO2) is an important material for this development and is, therefore, one of the most investigated thermochromic materials. It changes its transmittance in the infrared spectral range in response to a changing temperature. In this study, VO2 coating was deposited on ultra-thin flexible glass in a continuous roll-to-roll sputtering process. The thermochromic layer had a thickness of 70 nm, and it was embedded between two zirconium oxide layers of 170 nm each. The luminous transmittance of the stack was 50%. A solar modulation of 9.6% was reached between the low and high-temperature states. The transition temperature between the cold infrared transparent and the warm infrared opaque state was determined to be 22°C. Different application scenarios for this material were evaluated. The modulation of the solar transmittance was calculated for the combination of VO2 with state-of-the-art low-e coatings. Our findings show that such a combination does not offer a benefit for reducing the energy demand of a building. However, a stand-alone implementation of thermochromic coatings has a high potential if the energy consumption of the building is dominated by cooling demands.