Energy Retrofit and Economic Evaluation Priorities Applied at an Italian Case Study

Abstract In OCSE and developed Countries, the sectors which mostly suffered the 2008 financial and economic crisis, was the construction and real estate sectors. Furthermore, the buildings are responsible of about 40% of incidence on emission. The economic crisis did not allow realizing new buildings, and the existing buildings have too much greenhouse emission, that needs to be reduced. The Energy Retrofit could be a way to improve both sectors, because it reduces emissions and helps the real estate sector. However, the Energy Retrofit has some difficulties in order to evaluate both economic and technical solution. In this paper we present an Energy Retrofit simulation about an Italian case study: one building typology that is supposed realized in several different periods, having different thermo-physic parameters. For each period, four energy retrofit actions will be applied, together with the software evaluation of energy performanc

The Attic and its Effect on the Energy Performance of Historic Buildings

Abstract This paper aims to investigate the problem of attics conservation or dismantling from historic buildings. The attic, unconsciously inherited and planned with the traditional building techniques, constitutes a precious architectural heritage in the field of historic housing in the whole European patrimony. In many cases, the peculiarities of the type of techniques and the use of traditional local materials are the reasons why attics constitute an evidence of an active culture of know-how that has to be preserved. Furthermore, the attic-mediated heat transfer between indoor and outdoor environments, contributes to the saving of building heat loss. Nevertheless, the practice of eliminating attics is particularly diffused, and building owner or architects, preferring to dismantle their structure, compensate this loss by using insulating boards to constitute the final roofing section

Exploring the Effects of Climate-Adaptive Building Shells: An Applicative Time-Saving Algorithm on a Case Study in Bologna, Italy

Adaptive façades represent a viable and effective technological solution to reduce the building energy demand for cooling while achieving interesting aesthetic effects on the building envelope to screen solar radiation. During the last decade, many different design solutions, including those based on shape memory alloys, have been experimented to obtain appropriate responses without being dependent on electro-mechanically actuated systems. Several recent and ongoing studies have been published in the scientific literature regarding the different actuator typologies, as well as the different properties of the materials used, which usually determine the adaptive solution characteristics after a series of complex and time-consuming simulations using specialised dy-namic modelling software. Due to the time and resources required, this kind of evaluation is usually delivered during the last and more advanced design stage as a form of assessment of al-ready-taken architectural and technological choices. The study reported in the paper aims to offer a quick, time-saving simplified algorithm to calculate the response of an adaptive façade, ac-cording to the ISO 13790 standards, to be adopted during the early design stage to evaluate the possible effects of design decisions. The study includes three main steps: (a) the conceptualisation of the adaptive solution considering the context conditions; (b) the definition of the calculation algorithm; (c) the application of the method to a test room in a case study building located in Bologna for supporting the discussion of the related outcomes

Indoor Environmental Quality in Low Energy Buildings

Abstract The Directives 2002/91/CE and 2010/31/UE greatly evolved the building and real-estate sector towards low energy building, both in the case of building retrofitting and new buildings. Thanks to the Energy Performance Certificate influence on the real estate market, or thanks to the economic crisis, as it is some new buildings - the best - were built with Energy Class A or Nearly Zero classification. The Energy Building Performance standards, e.g. CEN Umbrella and their transposition, will be improved in the future, in spite of this these should be considered solid, and designers, architects and engineers must apply technical strategies (e.g. high insulation, reduction of air leakage, use of renewable systems) in order to reduce building energy consumption. The new challenge will be to improve relations between Building Energy Performance and Indoor Environmental Quality (IEQ). As regards these relations, the CEN Umbrella provides to implement the Standard 15251. In the present paper we describe the results of IEQ monitoring in a low energy performance building (Class A+ less than 25 kWh/m 2 year). The results show that low energy performance building do not always guarantee a better category of IEQ, especially during the summer

"Energy Restoration and Retrofitting" - Rethinking Restoration Projects by Means of a Reversibility/Sustainability Assessment

Premise – One on big mistake in restoration and retrofit project are technical plant installation impact. In order to solve this kinds of problems in the course of the 80’s and 90’s of the 20th century - in Italy, the most fruitful timeframe for the debate on urban and monumental restoration – many valuable experimental interventions were made, which proved to be useful for the identification and finalization of methodological and operational strategies. Their exploitation and re-use requested however the set-up and retrofitting of installations key for the development of the recovery project. In view of the subsequent technological evolution, such interventions and adjustments have shown to be of particular impact. Furthermore the actual requirements needs, not only to replace obsolete installations but also to implement and upgrade the so-called reversibility criteria of such restoration interventions while integrating them with a new sustainability assessment and verification in terms of environmental, economic and energy sustainability. Objectives – Identification, by means of SWOT Analysis methodology, of retrofitting solutions for technical installations (heating, cooling and HVAC) vis-à-vis their interface with the architectural asset and the inherent project characteristics of installation devices. The aim is to show the efficacy of the solutions applied for the integration of the installation sub-systems chosen to guarantee the best micro-climate conditions.” Methods – Use of the “as build” [ex-post] verification vis-à-vis two sample cases of particular significance : 1) Turin, Recovery of the former Convento di S. Croce (16th-17th century) as university site – project by: A. Magnaghi et alia, 1980; 2) Turin, Preservative Restoration of the Chiesa e Coro di S. Pelagia, 17th century - project by: A. Magnaghi et alia]. In that respect, the following aspects are taken into consideration : a) the type characteristics of the installations made at the time of their deployment (1985) in comparison with the current installation solutions that could be potentially applied; b) the technological elements that led to the main project choices with verification of the geometric-functional parameters of the technological upgrade/retrofitting to confirm/disconfirm the related application ; c) the peculiar and autonomous features of the architectural intervention in the preservative restoration vis-à-vis the effects of the occurred historicizing of the intervention itself, i.e. the subsistence of qualifying elements that can co-exist with the different phases in the lifespan of the monumental building/unit. Conclusions – The combined use of two analytical tools can lead towards a more balanced assessment of the restoration intervention and the technological-functional retrofitting of the preserved works of art/heritage

Stressing the passive behavior of a Passivhaus: an evidence-based scenario analysis for a Mediterranean case study

This paper first reports the outcomes of a one-year measurement campaign of a passive house built in the Mediterranean climate of Cesena (Italy) in terms of thermal comfort parameters temperature and relative humidity and Indoor Environmental Quality (IEQ) parameter CO2 concentrations. The design carried out with the help of the steady state Passive House Planning Package (PHPP) was able to guarantee good comfort conditions during the heating period, but on the other hand, overheating occurrences during the cooling season have been recorded for almost 50% time according to EN 15251 Standard. Further analyses conducted with the help of dynamic simulations in EnergyPlus allowed identifying the insulation levels and ventilation mode as the key design factors to change in order to reduce overheating to less than 20% of time while keeping a comfortable indoor environment in winter. The simplifications that can be made by reducing the insulation material thickness (up to a third of the original value) on the roof and on the walls, replacing triple-glazed windows with double-glazed windows and implementing a hybrid ventilation strategy instead of using Mechanical Ventilation with Heat Recovery (MVHR) alone could also lead to economic savings. These savings, due to both lower construction costs and operational energy savings, amount to 8755 euros in terms of Net Present Value (NPV) over 30 years' time. The Passivhaus Standard can still be regarded as a good reference for designing low-energy and comfortable houses in a Mediterranean climate if some simplifications are made according to detailed building performance simulations

A Study on Parametric Design Application to Hospital Retrofitting for Improving Energy Savings and Comfort Conditions

The scientific literature offers a wide range of studies evidencing the progress done in the retrofit actions dealing with the current building stock; however, renovations of hospitals are still an open field of research due to their typical complexity that is usually associated with a very challenging updating processes to maintain or increase operational level. The paper provides a synthesis of a study developed by a team of the Department of Architecture for Saint Orsola Hospital in Bologna with the scope to explore innovative retrofitting strategies. The brief provided by the management unit of the hospital was connected to the general renovation plan involving the entire site and particularly some existing buildings taking into account some limitations concerning budget availabilities and everyday activities needed to ensure acceptable service level for the end users. The design approach starts from defining a basic unit (a typical hospital room) that is deeply analyzed to report the starting conditions (indoor environmental parameters) and then used to simulate the potential impacts of retrofitting actions on its performances. The results allowed to parametrically develop a step by step strategy scaled on each building sector and on the building as a whole to evaluate the global impact on energy performances while considering time and costs of each retrofitting options

Real Estate market, energy rating and cost. Reflections about an Italian case study

The Directive EPBD introduced Energy Performance Certificate (EPC) an energy policy tool. The aim of EPC is to inform building buyer about energy performance (and energy cost) of buildings. They represent a specific energy policy tool to orientate building sector and retail market toward higher energy efficiency building. The Real Estate market was built in different periods, and in each of these periods the building envelope or the heating plant had different kinds of energy performance. Therefore, in real estate, each building-period has a determinate incidence respect total existing buildings, and they have different energy consumption incidence respect total energy national consumption. The EPBD recast highlight the relation between building elements or technical building system, energy rating and cost-optimal levels of minimum energy performance requirements. In present paper a discussion about Directive's news, Italian EPC and real estate market prospective is presented. Furthermore we proposed a reflection about link between energy cost, energy rating and building property value

Indoor Thermal Comfort of Pregnant Women in Hospital: A Case Study Evidence

Despite studies on thermal comfort being consolidated in the scientific literature, people\u2019s well-being in some specific conditions and places, such as hospitals, requires to be further explored. The paper describes the methodological approach adopted to evaluate thermal comfort level and perception of pregnant women hosted in the obstetric ward of a test-bed case (Sant\u2019Orsola hospital in Bologna, Italy). The methodology adopts a mixed approach that compares the results of on-site monitoring by probe (as quantitative data) with the ones of a survey (questionnaire form) delivered to the involved subjects (as qualitative data) to understand if metabolic alteration may influence the pregnant women\u2019s perception of comfort conditions. The first follows ISO 7730, the second, ISO 10551. The comparison between the instrumental collected data and the outcomes of the survey revealed a wide gap between TSV (Thermal Sensation Vote) and PMVm (Predicted Mean Vote, measured on-site). The reason can be identified in the use of a standardized metabolic unit from ISO that does not correctly reflect the physiologic condition of pregnant women. Following a trial and error methodology, a met value for pregnant women is accordingly proposed. Moreover, an adaptive thermal comfort approach is adopted. This research is a first step towards the definition of specific thermal comfort in a hospital ward hosting pregnant women and more generally offers a reflection about the need to define specific met in the standards for some particular categories (children, elderly, pregnant women, etc.) when investigating thermal comfort

Sun-Shading Sails in Courtyards: An Italian Case Study with RayMan

Forecasts of a drastic increase in temperatures in the coming decades are driving the adoption of design strategies and solutions to improve the livability of urban environments. Increasing attention is being paid to the thermal comfort of open spaces by both designers and researchers. Nature-based solutions and man-made devices to improve the comfort of outdoor spaces during summer are spreading, but effective, easy simulation and design support tools for this purpose are still lacking, as most of the available software such as ENVI-met or RayMan cannot model such devices. As Phys-iological Equivalent Temperature (PET) is one of the most relevant and comprehensive indicators of Outdoor Thermal Comfort (OTC), this study aims to investigate PET variations of different artificial shading systems and propose a simplified methodology for assessing them through analytical sim-ulations with RayMan software. When modeling the shading elements, the trick adopted for this purpose is to associate different cloud densities with the shading provided by the screens, thus overcoming a gap that affects the software. The procedure is digitally tested in a covered courtyard case study in Bologna (Italy). Diverse options proposed by the designers for textile screening mate-rials have been compared, showing that these reduce by at least 1 °C the PET-gauged thermal stress. Beyond specific results, the main outcome of this study is the procedure developed to simulate sun-shading sail effects on OTC by means of RayMan, which can support designers in planning effective solutions for open space livability in summertime