Decision-support method for profitable residential energy retrofitting based on energy-related occupant behaviour

Low-carbon energy retrofitting in buildings plays an important role because 75% of European buildings are considered inefficient and more than 40% are currently over 50 years old. The economic reinvestment of energy retrofit actions through reduced energy bills, as energy directives promote, greatly depends upon the energy consumption patterns. In support of the decision-making process towards a low-carbon energy transition in multi-family buildings, this paper introduces a novel assessment method that evaluates the profitability of energy efficiency measures, according to standard operating conditions derived from energy performance certificate procedures and real occupant energy consumption scenarios, through a parametric analysis. The aim is to assess the real energy and economic savings of retrofitting actions, depending on different energy-related occupant scenarios, and to enable comparisons with other buildings, providing a valuable model to identify the most feasible and low-carbon energy strategies in residential energy retrofitting. A Spanish multi-family building from 1942 is taken as the reference case study. The results show that energy savings for dwellings vary up to 80%, and the net present value per dwelling differs by up to 20,000V between different energy consumption patterns. The most appropriate energy efficiency measures according to low, medium or high consumption scenarios are highlighted

Issues of energy retrofitting of a modern public housing estates. The ‘Giorgio Morandi’ complex at Tor Sapienza, Rome, 1975-1979

Energy retrofitting of historical residential buildings represents today an interesting challenge of the building sector. This is true especially in Italy where great part of the national buildingstock dates back to pre-modern and modern times and, especially, to the decades between the 1960s and the 1980s. Most of these buildings, in fact, offerthermal performances that are inadequate to current requirements in terms of energy efficiency, human comfort as well as to seismic safety. This study focuses on the energy retrofitting of public housing estatessuch as the“Giorgio Morandi” complex at Tor Sapienza in Rome. The upgrading of this complex is outlined, taking into account issues of energy saving but, also, constraints related to the historical values of the buildings. Intervention options able to improve energy efficiency are therefore foreseeable only in strict observance of cultural heritage values, which entails a deep analysis and survey of the existence in order to identify respectful, correct and feasiblesolutions

Comparing Energy Improvements and Financial Costs of Retrofitting Interventions in a Historical Building

In Italy, energy improvements of historical buildings are one of the key aspects to reach the EU 2020 goals on energy efficiency. Many papers are available in literature to recover and retrofit historical buildings, considering different types of interventions aimed to increase energy efficiency in existing building. Considering the most common retrofit interventions in historical building, this paper focuses on the estimation of the energy improvements and related financial costs of four considered scenarios on the building envelope of the “pharmaceutical chemistry” historical building located in the Sapienza University Campus of Rome. Additionally, a cogeneration system and the installation of a PV system have been included among the considered scenarios, in order to analyze their energy performance jointly with feasible retrofitting interventions. Research methods included a dynamic simulation of building thermal loads in the current state and in the scenario after each considered intervention carried out using TRNSYS software. Furthermore, yearly savings, investment cost and payback periods have been evaluated for each considered scenario, taking into account both the purchase prices of the saved energy and the amounts needed to realize related retrofitting interventions. In conclusion, among the feasible interventions in historical buildings, the obtained results provide useful data about what strategy offers the best energy performance improvement if compared with its financial costs. Results could provide recommendations for other historical buildings that need retrofitting interventions for improving their energy efficiency

A Short Guide to Setting Up a City Scale Retrofit Program

Buildings represent 38.9% of U.S. primary energy use and 38% of all CO2 emissions in the U.S. Though simple, relatively low-cost measures such as insulation, and lighting upgrades can be done in almost every building to reduce energy use and save money on utility bills, current retrofitting program capacity is limited. Most existing programs are either available only to income-eligible individuals or those with the money up-front to do the work. Furthermore, many current retrofitting programs only create low-wage, short-term jobs rather than providing pathways into sustainable careers in construction and green building. Clearly, a new model is needed. This guide by Green For All and the Center on Wisconsin Strategy provides a model for designing and implementing weatherization and retrofitting programs on a citywide scale, with a goal of making such retrofits available to all and realize their potential to address climate change, put people to work, and reduce our energy bills

Experimental assessment and retrofit of full-scale models of existing RC frames

PSD tests on two full-scale models of existing non-seismic resisting RC frame structures are described. The testing program covered several aspects, namely assessment of seismic performance of existing frames without and with infill panels, retrofitting of the bare frame using Selective Retrofitting techniques, strengthening of the infill panels using shotcrete and retrofitting of the frame using K-bracing with shear-link dissipators. The main results from the tests are summarized and discussed and the conclusions are drawn. The tests on the bare frame have shown how vulnerable are existing structures constructed in the 60’s and the beneficial effects of infill panels were confirmed from the tests on the infilled frame. Important improvements, in terms of seismic performance, were achieved by the retrofitting of the frames. However, it was also confirmed that strengthening of the existing infill panels in poorly detailed frames may lead to dangerous ‘local’ failures, such as the shear out of the external columns

OptEEmAL: Decision-Support Tool for the Design of Energy Retrofitting Projects at District Level

Designing energy retrofitting actions poses an elevated number of problems, as the definition of the baseline, selection of indicators to measure performance, modelling, setting objectives, etc. This is time-consuming and it can result in a number of inaccuracies, leading to inadequate decisions. While these problems are present at building level, they are multiplied at district level, where there are complex interactions to analyse, simulate and improve. OptEEmAL proposes a solution as a decision-support tool for the design of energy retrofitting projects at district level. Based on specific input data (IFC(s), CityGML, etc.), the platform will automatically simulate the baseline scenario and launch an optimisation process where a series of Energy Conservation Measures (ECMs) will be applied to this scenario. Its performance will be evaluated through a holistic set of indicators to obtain the best combination of ECMs that complies with user's objectives. A great reduction in time and higher accuracy in the models are experienced, since they are automatically created and checked. A subjective problem is transformed into a mathematical problem; it simplifies it and ensures a more robust decision-making. This paper will present a case where the platform has been tested.This research work has been partially funded by the European Commission though the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement No 680676. All related information to the project is available at https://www.opteemal-project.eu

Local Energy Efficiency Interventions by the Prioritization of Thermal Zones in an Historical University Building

Architectural constraints are a crucial aspect in energy retrofitting of historic buildings. Usual global interventions are often not allowed since preserving historical values of the building stock is mandatory. In this paper, the authors provide an alternative procedure by identifying the most profitable local interventions in order to maintain the architectural values during the restoration and energy retrofitting operations. So, thermal zones prioritization is the key element considered in this study. Its aim is to analyse which energy efficiency measures could be applied to a listed building, but at certain technological elements rather than a unique choice for the entire building envelope. Thus it will prove that you can work with individual elements of the building without compromising the protection of architectural good. The attention was placed in promoting single measures and improving the quality of the built environment. The case study is an historical building in Rome, currently used for university purposes. The analysis was carried out through a building simulation model so that to assess the building energy performance before and after the selected interventions. The chosen software is TRNSYS. This approach shows how interventions, usually not applicable at the building scale, would be beneficial if applied at local scale such as a single thermal zone or a single technological unit. The authors built a reference scenario and, for each identified thermal zone, tested the energy efficiency improvement in terms of heating demand reduction coming from the hypothesized local intervention

South Bronx Residents Solution on Greening our 'hood

The South Bronx has struggled for years with three of the most pressing social and economic inequities that affect urban, low-income communities of color: high unemployment, poor public health, and substandard housing conditions. Compared with other neighborhoods in New York City, the South Bronx community bears an unequal share of the burden in each of these areas. The South Bronx is home to the highest unemployment rate in the city at 12.6%, claims one of the highest rates of asthma and obesity in the country, and residents are exposed to housing infested with cockroaches, mold and other allergens at a higher rate than anywhere else in the City.After a year-long community visioning process, where members of MOM identified the need to address the intersecting issues of housing, environmental injustice and unemployment, members of MOM decided to research a public policy solution that could address each of these interrelated issues simultaneously. This solution is a green jobs program, which we define as employment opportunities that improve the environment. After surveying hundreds of residents in the South Bronx, and exploring a variety of existing and proposed green jobs programs found in New York and elsewhere throughout the country, members of MOM have decided to call for the creation of a green jobs program focused in the New York City Housing Authority to retrofit each of the South Bronx neighborhood's 90 public housing developments to be more energy efficient. If implemented successfully, this green jobs program could create thousands of new jobs while simultaneously improving public health and housing conditions for low-income South Bronx residents

Seismic analyses of a R/C building: study of a retrofitting solution

The preliminary experimental results from the tests on a 4-storey R/C frame structure are presented and discussed. The full-scale model is representative of the common practice of 40~50 years ago in most south European countries. Special attention is devoted to the study of a retrofitting solution based on bracing and rubber dissipaters, which intends to increase stiffness and damping reducing consequently the earthquake deformation demands

Dynamic nonlinear analyses for the 4-storey infilled R/C frame: study of a retrofitting solution

A research project on assessment and retrofitting of R/C frame structures is currently being developed under the research programme of the ICONS TMR-research network. This paper presents and discusses the preliminary experimental results from a 4-storey bare frame representative of the common practice of 40~50 years ago in most south European countries and devotes special attention to the study of a retrofitting solution based on bracing and rubber dissipaters, which intends to increase stiffness and damping reducing consequently the earthquake deformation demands.O estudo aqui apresentado concentra-se numa solução de reforço de um pórtico utilizando contraventamentos (k-bracing) com perfis de aço em conjunto com elementos elastoméricos de dissipação. Os resultados das análises não lineares da estrutura com e sem alvenaria e com reforço são apresentados e discutidos. Na segunda parte da comunicação apresentam-se os resultados experimentais já disponíveis e discute-se o problema da modelação recorrendo aos resultados experimentais e comparando os resultados obtidos com diferentes tipos de modelos