Retrofit de la construcción mediante paneles prefabricados: una reseña del estado del arte = Building Retrofit through prefabricated panels: an overview on the state of the art

The main aim of this paper is to provide an overview of the use of prefabricated panels in external building retrofitting. Building retrofit represents a pivotal point in terms of energy efficiency, connected to the great amount of existing buildings, both public and private, all around Europe. The need of intervention is underlined by different European Directives, as well as by Horizon 2020 roadmap. Many research works and projects are focusing on the theme of prefabrication in retrofit, stressing the importance of this strategy. The review of the state of the art shows several approaches in terms of prefabricated panels: a critical classification of these projects distinguish between systems based on large and small panels, systems for extensions based on structural panels, and partially prefabricated systems. The classification is useful as it can help in understanding further development of prefabricated panels, underlining the advantages and disadvantages of the systems. The main challenges are linked to design, fabrication, transport and installation. An overview of those issues is also provided, stressing the main innovation fields to be further investigated, and the possible future developments of prefabrication in building retrofit

Identification of technological and installation-related parameters for a multi-criteria approach to building retrofit

Building retrofit is a main concern to reach EU de-carbonisation goals of 2050. Façade retrofit plays a pivotal role in the reduction of energy consumption in buildings: several strategies are in fact available, both in terms of on-site systems and prefabricated elements. The research question arising regards therefore how to choose the best-suiting residential retrofit strategy between different technological systems. In this sense, a current lack of diffusion of Decision Support Systems between can be underlined, as decisions mainly derive from previous experiences. An optimizing strategy that could express the goals of the many actors involved in the building process is required. In order to consider the impact of different criteria on the choice, multi-criteria methodologies could be effective. Existing similar methods mostly focus uniquely on energy performance, or follow the categories of environment, economy and society. What is currently lacking in available tools regards production-linked and technological aspects, related to e.g. façade morphology, and building site features. The aim of this paper is to identify relevant parameters related to installation and economy aspects, for a multi-criteria approach to be used in the choice of the most suitable building retrofit strategy. The methodological approach is therefore provided, and the choice of parameters, carried out by means of interview with actors of the building process, is explained. The criteria selection and the subsequent criteria weighting phase is to be carried out by means of interviews and surveys to the actors involved in the building process. The application on case-studies will offer the opportunity to assess the effectiveness of the method

A Multi-Kernel Multi-Code Polar Decoder Architecture

Polar codes have received increasing attention in the past decade, and have been selected for the next generation of wireless communication standard. Most research on polar codes has focused on codes constructed from a $2\times2$ polarization matrix, called binary kernel: codes constructed from binary kernels have code lengths that are bound to powers of $2$. A few recent works have proposed construction methods based on multiple kernels of different dimensions, not only binary ones, allowing code lengths different from powers of $2$. In this work, we design and implement the first multi-kernel successive cancellation polar code decoder in literature. It can decode any code constructed with binary and ternary kernels: the architecture, sized for a maximum code length $N_{max}$, is fully flexible in terms of code length, code rate and kernel sequence. The decoder can achieve frequency of more than $1$ GHz in $65$ nm CMOS technology, and a throughput of $615$ Mb/s. The area occupation ranges between $0.11$ mm$^2$ for $N_{max}=256$ and $2.01$ mm$^2$ for $N_{max}=4096$. Implementation results show an unprecedented degree of flexibility: with $N_{max}=4096$, up to $55$ code lengths can be decoded with the same hardware, along with any kernel sequence and code rate

District Geometry Simulation: A Study for the Optimization of Solar Façades in Urban Canopy Layers

open4This paper shows the results of a research aimed at assessing the amount of energy that can be produced by solar envelopes (facades and roofs) in urban contexts.A preliminary set of simulations was carried out, through dynamic yearly analyses on a sample building, to identify the main parameters influencing the availability of solar radiation and to optimize the building's shape. The general target is to maximise solar radiation available on the external building envelope, in order to exploit it through building integrated solar systems.Furthermore, the effect of reflected solar radiation has been analysed by simulating different finishing materials (green façades, glazed façades, concrete façades and aluminium façades) on the neighbouring buildings.G. Lobaccaro; F. Fiorito; G. Masera; T. PoliLobaccaro, Gabriele; F., Fiorito; Masera, Gabriele; Poli, Tizian

Exploration of Adaptive Origami Shading Concepts through Integrated Dynamic Simulations

This paper presents integrated energy and lighting simulations as a part of wider research focused on the form-finding process of adaptive shading concepts and on the actuation of shading movement using shape memory alloys (SMAs). The use of this new type of microactuator in responsive architectural components presents a challenge because of the limited contraction state of the SMAs. Hence, origami shapes were considered to amplify shading movements thanks to their geometric properties. This study exploited the visual and thermal comfort of a south-oriented office located in Milan, Italy, that was equipped with adaptive origami shading. Two-hundred and ten shapes were considered and the geometry, contraction states, and surface materials were considered as variable properties. The final aim was to explore the potential of adaptive origami shadings in controlling visual and thermal comfort. Daylight illuminance (UDI), daylight glare probability (DGP), and total energy (TE) demand (for cooling, heating, and lighting per year) were used as main metrics for understanding the environmental benefits of the proposed shading devices

shaping an origami shading device through visual and thermal simulations

Abstract This paper presents the first results of a research work aimed at the optimisation of a shading system through parameters of visual comfort – Useful Daylight Illuminance (UDI), Daylight autonomy (DA) and Daylight Glare Probability (DGP) – and Total Energy (TE) consumption (cooling, heating and lighting per year). The goal is to define a shading system for office buildings that delivers visual comfort for users whilst reducing energy consumption for indoor climate control and artificial lighting. As the design of the shading system considers the use of shape memory alloys (SMA) as micro-actuators to accomplish solar adaptation, Origami pattern has been adopted to guarantee a relatively large displacement of the shading system with a small deformation of the SMA wires actuators. Thanks to this shape change, generating overlapped pleats and angle variation and using different materials, it has been possible to provide alterations of the direct light transmission inside the building while maintaining a certain degree of diffuse light component

Investment Grade Energy Audit: A Financial Tool for the Cost-effective Renovation of Residential Buildings

The renovation of the existing building stock is a top priority for the European Union. In order to reach the ambitious goal of decarbonization by 2050, new financial instruments, incentives or grants and loans to support energy efficiency should be implemented, especially for public bodies. The proposed method aims to be a tool to stimulate cost-effective deep renovations. The results of its application to a multi-owner building show the benefits of using Energy Service Companies and Energy Performance Contracting to finance renovations and implement plans to maintain or improve energy efficiency in the long term

Kinetic Solar Skin: A Responsive Folding Technique

The paper focuses on optimized movements analysed by means of Origami, the Japanese traditional art of paper folding. The study is a way to achieve different deployable shading systems categorized by a series of parameters that describe the strengths and weaknesses of each tessellation. Through the kinetic behaviour of Origami geometries the research compares simple folding diagrams with the purpose to understand the deployment at global scale and thus the potential of kinetic patterns’ morphology for application in adaptive facades. The possibilities of using a responsive folding technique to develop a kinetic surface that can change its configuration are here examined through the variation of parameters that influence kinematics’ form. Moreover, in order to perform the shape change without any external mechanical devices, the use of Shape Memory Alloy (SMA) actuators has been tested

Prefabrication as large-scale efficient strategy for the energy retrofit of the housing stock: an Italian case study

In this work a multi-story residential building located in Cinisello Balsamo, near Milan, was considered as case study for the application of two new prefabricated building systems for the energy retrofit. The first one, developed within EASEE, a European project funded by 7th Framework Program, consists in a preassembled insulated panel for the retrofit of facades, based on two TRC thin precast layers rigidly connected to an EPS core. The panels can be easily applied on the external side of existing facades without the use of scaffoldings, providing an additional efficient insulation as well a new external cladding. The second one consists in a preassembled timber panel for existing pitched roofs. The process includes the substitution of the existing roof with modular integrated panels with a high content of recycled materials that can be easily fixed on the existing structures (timber frames, concrete, masonry, etc.). The combination of the two prefabricated construction systems, applied on the case study, allowed the reduction of the building energy demand by 82%