Multi-family Residential Buildings Research Articles

Case study of condominium management in Brazil: survey of 30 years of maintenance and renovation costs of a 1982 multifamily residential building

Case study of condominium management in Brazil: survey of 30 years of maintenance and renovation costs of a 1982 multifamily residential building

Development and optimization of an energy saving strategy for social housing applications by water source-heat pump integrating photovoltaic-thermal panels

Residential buildings account for 84 % of Italy's built environment, playing a pivotal role in the EU's aim to cut GHG emissions by 55 % through enhanced energy efficiency and climate adaptation. This necessitates comprehensive energy retrofit initiatives, especially in sectors like social housing, which has been relatively overlooked in terms of energy efficiency strategies. This study focuses on a multi-story building from the 1980s in Rome, implementing an innovative energy system proposed by the RESHeat European project. This system, aimed at standardizing energy retrofits for late 20th-century social housing, leverages the underexplored potential of water-source heat pump (WSHP) systems. The novelty of this research extends to its examination of multi-family housing, a sector that has seen less attention compared to public spaces and smaller residential buildings. Through experimental validation and annual dynamic simulations using TRNSYS and Simulink, the research compares the existing heating system with a proposed upgrade that includes a WSHP and Photovoltaic-Thermal (PVT) panels. This upgrade demonstrated a significant efficiency improvement, achieving an annual COP of 6.1 for the WSHP and a 36 % Primary Energy Savings (PES) from the PVT panels, showcasing the effectiveness of these technologies in enhancing the energy profile of multi-family residential buildings.

Optimizing indoor air quality and energy efficiency in multifamily residences: Advanced passive pipe system parametrics study

AbstractThis research focuses on enhancing natural ventilation in multifamily residential buildings to improve air quality and minimize reliance on mechanical ventilation, thereby reducing energy consumption. The study pioneers the integration of passive pipe systems within structural floor slabs and building envelopes, aiming to overcome the inherent challenges of indoor environmental quality (IEQ) related to design constraints, occupant behavior, and urban context. Our innovative approach, utilizing a novel application of Grasshopper for precise architectural modeling and Ansys for advanced multiphysics simulation, enables a detailed comparative analysis of airflow dynamics across various system configurations. A comprehensive literature review underscores the significance of natural ventilation as a key passive cooling strategy, vital for reducing energy use and enhancing IEQ in the face of urbanization challenges. Our empirical findings reveal that configurations with more inlet and outlet pipes significantly outperform simpler ones, with a notable configuration of 11 pipes (5 × 6) achieving an actual-to-required ventilation rate increase in 158.15%. This evidence highlights the substantial benefits of adopting complex system configurations for improved ventilation efficiency. The study’s outcomes include impactful design recommendations for adopting enhanced natural ventilation strategies in multifamily residential buildings. These recommendations promise to inform sustainable urban planning and building management strategies, offering a scalable solution for cities seeking to balance growth with environmental sustainability. By demonstrating the clear advantages of targeted passive cooling interventions, this research contributes valuable insights toward achieving energy efficiency and superior IEQ in residential buildings, paving the way for future exploration in diverse climatic and urban contexts.

Analysis of the Energy, Environmental and Economic Efficiency of Multi-Family Residential Buildings in Poland

Improving the energy efficiency of buildings is one of the main challenges facing Europe in the context of climate neutrality policy. In this article, the authors decided to investigate the impact of thermal insulation of building envelopes and the type of ventilation on the energy efficiency of multi-family buildings located in different Polish cities. In accordance with EU directives, economic analyses of the costs incurred during the lifecycle and calculations of CO2 emissions were carried out for the analyzed facilities. It was determined what measures need to be taken under Polish climatic conditions in order to meet the requirements for improving the energy efficiency of multi-family buildings. The multi-criteria analyses presented in this article provide a voice in the discussion of the issues related to the achievement of the energy performance of buildings with almost zero primary energy demand (nZEB). Based on the conclusions of the research conducted, it was possible to develop general recommendations for investors and designers of multi-family residential buildings characterized by energy efficiency and reduced environmental impact.

Parametric simulation tool for the enviro-economic evaluation of energy renovation strategies in residential buildings with life cycle thinking: PARARENOVATE-LCT

The EU regulations require long-term renovation strategies (LTRS) for the energy transition of the existing building stock, emphasising the importance of the whole-life carbon evaluation and the cost-effectiveness of the processes. The building performance simulation (BPS) tools combined with the integration of the life cycle thinking (LCT) are considered a promising approach for evaluating the renovation of buildings. Besides, the performance gap due to occupant behaviour (OB) and the uncertainty of the economic scenario is an essential barrier to the accurate assessment of renovation strategies in residential buildings. The objective of this study is to develop a simulation tool to evaluate the environmental and economic sustainability of energy renovations in residential buildings based on LCT, considering the OB diversity and economic uncertainty. For this, the study develops the PARARENOVATE-LCT tool. This script-based tool combines the dynamic BPS and the integration of the environmental life cycle assessment (LCA) and the economic life cycle cost (LCC), evaluating different renovation strategies in multiple scenarios based on the combination of multiple variables of archetype, climatic zone, OB patterns, economic scenario and orientation. The methodological tool is applied in a case study of the most common archetypes of single-family and multi-family residential buildings of the Basque Country, in northern Spain. The results show how the tool can prioritise strategies, analyse the significance of baseline scenario parameters, and measure the influence of the LCT application. This way, the study provides a methodological tool as a new approach towards developing policies and plans to answer the EU requirements.

Features of the Design of Residential Buildings

The article discusses each type of residential and public buildings has its own spatial planning solution, the design of which reflects a rather complex workflow. When designing multi-family residential buildings, economic factors are primarily taken into account. In particular, the construction of residential buildings in Uzbekistan has its own historical tradition. The houses were built in two versions -national and European. These houses mainly consist of houses with separate courtyards. This study employs a qualitative research approach, drawing insights from architectural literature and historical records to examine the design features of residential buildings in Uzbekistan. Data collection involves literature review, analysis of architectural plans, and examination of historical documents. The analysis reveals that the design of multi-family residential buildings is influenced by various factors, including economic considerations, cultural heritage, and historical traditions. In Uzbekistan, the architectural landscape reflects a blend of national and European styles, each with its own spatial planning solutions and design elements. Traditional houses with separate courtyards not only provide privacy and security but also contribute to the overall aesthetics of residential neighborhoods. Additionally, economic factors play a significant role in shaping the design process, with cost-effective construction methods and materials being prioritized in residential building projects.

Decision support method for optimal modernization of residential buildings

Decision-making for the refurbishment of multi-family residential buildings is a complex and computationally difficult task. Therefore, the authors have developed a model that supports modernization planning in a long-term and comprehensive manner, i.e. from assessing the building to indicating the optimal scope of modernization. The comprehensive scope of the model includes the acquisition and provision of relevant knowledge to the model. The original methods proposed for its acquisition are derived from common expert knowledge based on linguistic terms. The methods adopted are not mandatory and may be replaced by others that provide more reliable knowledge. The fundamental aim of the proposed approach, however, is to select the optimal modernization option and allocate it over the planned modernization time horizon. An innovative optimisation approach based on decision matrices is used, allowing the selection of possible scenarios of repair options at each stage. These matrices are a set of constraints written in binary variables allowing the optimisation calculus to maintain a fixed sequence of repairs. In addition, the solutions used in the optimisation modules make it possible to take into account assumptions regarding the assumed assessment of the building’s condition and financial constraints. The developed model provides a practical and versatile tool that can be used by managers at the maintenance stage of residential buildings.

ENVIRONMENTAL PROTECTION ACTIVITIES IN BULGARIA – COMPARATIVE ANALYSIS IN REGIONAL ASPECT

Environmental protection activities differ according the specifics of the regions. They lead to optimal use of resources, reduction of climate impact, ensuring security of energy supply, improving the health of ecosystems etc. The aim of the paper is to be prepared a comparative analysis between the planning regions in terms of environmental protection activities and on this basis to be determined the place of each region and to be evaluated the effectiveness of the financial sources used for environmental protection activities. The paper presents literature review of some environmental protection activities. The paper analyzes data related to the environmental protection activities undertaken in the planning regions related to household waste submitted for recycling, waste water discharged from treatment plants, installed renewable energy sources capacities, research and development expenditure, number of buildings financed under the National program for energy efficiency of multifamily residential buildings. Comparative analysis of environmental protection activities by planning regions is prepared in order to be presented the trends of some indicators and to be made a comparison between the regions. On the basis of the data analysis, the comparison between the planning regions for the period 2017 -2021 was made, and they were ranked in three groups – active, moderately active and low active. The analytical part of the paper also includes DEA analysis to be found the most effective region according to the chosen inputs. In all DEA models, the aim is to evaluate the effectiveness of indicators such as tangible fixed assets (TFA) with ecological use, expenditures for research and development and financial resources under the Operational program environment (OPE). These indicators are defined as Inputs. For outputs are chosen generated municipal waste, waste water discharged without treatment, CO2 emissions and destroyed territories. Based on the analysis are made some general conclusions and recommendations for increasing the engagement of the region to carry out environmental protection activities. The South Central and South Western regions are the most active in terms of carrying out activities that lead to environmental protection, the South Eastern and North Eastern regions can be defined as moderately active, and the North Central and North Western regions as low active in terms of environmental protection activities. In order to increase the engagement of the regions to carry out environmental protection activities, various initiatives can be taken, most often related to better understanding of ecological benefits, taking political actions and implementation of regulations in economic sectors related to the environment and natural resources, spreading of good practices. Key words: environment, planning region, regional differences JEL: P28, R11

Exploring Historical Traditions in Spatial Planning for Multi-Family Residential Buildings

This study delves into the intricacies of spatial planning solutions for various types of residential and public buildings, highlighting a complex workflow in their design. Focusing on multi-family residential buildings, the research primarily considers economic factors during the design process. Specifically, it explores Uzbekistan's unique historical tradition in constructing residential buildings, offering insights into two distinct versions - national and European. Notably, these buildings predominantly feature separate courtyards. Through a comprehensive analysis of goals, methods, results, and implications, this study contributes valuable knowledge to the global discourse on architectural design and spatial planning.
 Highlights:
 
 The study explores the complexity of spatial planning solutions for residential and public buildings.
 Economic considerations play a crucial role in the design of multi-family residential buildings.
 Uzbekistan's historical tradition in residential construction reveals unique architectural features.
 
 Keywords: Planning Solutions, Residential Buildings, Architectural Design

Financial Aspects of Sustainable Rainwater Management in Small-Scale Urban Housing Communities

Sustainable rainwater management may counteract the effects of climate change and significantly improve the distorted water balance in urbanized catchments. However, despite the hydrologic advantages of rainwater management, acceptance and willingness-to-pay in the local society are required. This paper presents an assessment of the financial aspects, i.e., the cost-efficiency and economic feasibility, of various designs of rainwater management for a small-scale urban housing community in Lublin, Poland. The research was performed for a housing community covering approx. 1.38 ha and five multi-family residential buildings. The proposed designs covered rainwater harvesting systems, supported with extensive green roofs, with rainwater retained in underground or above-ground reservoirs, used with variable demand for watering the green areas and for underground parking lot flushing. For each designed variant, the investment as well as operation and maintenance costs were estimated. The assessment of the cost-efficiency and profitability of the proposed rainwater management systems was based on three indicators: Dynamic Generation Costs, Payback Period and Benefits–Costs Ratio. The performed calculations showed that only two designs, utilizing above-ground rainwater reservoirs, could be assessed as economically profitable. Thus, local communities may be unable to financially sustain investments in sustainable rainwater management, so it seems that financial support is required.

The bidirectional substation for district heating users: experimental performance assessment with operational profiles of prosumer loads and distributed generation

The regulatory European and national policies outline the role of efficient district heating in achieving mid and long-term decarbonization targets. Prosumers could be equipped with bidirectional exchange substations to increase the local production contribution. The present paper evaluates the contribution of a bidirectional substation in maximizing the use of thermal energy produced locally by renewable sources or waste heat in a densely populated area, considering the limitation due to the non-contemporaneity of production and consumption and possibilities to overcome them. The substation prototype and the control system were tested in operational conditions, assuming the district heating network operating at two temperature levels (80 °C/50 °C and 60 °C/30 °C for supply and return) and applying the hardware-in-the-loop technique for coupling the substation in real-time with data-driven thermal loads (multi-family residential building) and production (solar panels and waste heat) profiles. The various energy flows in the substation are presented for representative days, resulting in a district heating contribution to the user’s load ranging between 99.8 % (winter day) and 21.8 % (summer day). The net-metering mechanism was considered, and the assessment extended to the entire year. The local production contribution to the user’s load ranges between 24 % and 100 %, depending on the system configuration considered.

“En-Solex”: A Novel Solar Exoskeleton for the Energy-efficiency Retrofitting of Existing Buildings

The energy retrofitting of the existing building stock is one of the current challenging strategic objectives on the way to the European target of climate neutrality by 2050. According to the Renovation Wave plan, around 35 million existing buildings need to be upgraded to the highest energy efficiency level by 2030, and innovative technological solutions are required to achieve this ambitious goal. This paper proposes a novel solar exoskeleton for the energy and architectural retrofitting of existing buildings, called En-Solex. The system, which consists of an external steel frame that wraps around buildings like a double skin, combines passive solar gain control (shading and greening) with high-efficiency active solar systems (PV panels) optimised for integration into existing building facades. The energy-saving potential of the system with different façade configurations is evaluated on a multi-family residential building located in a Mediterranean climate. The dynamic energy simulations show that the proposed solution can reduce the energy demand for space heating and cooling by 33.4% and 25.5% respectively. The En-Solex system integration combined with generator replacement results in a maximum heating and cooling reduction equal to 80.7% and 59.6% respectively. The surplus of electricity generated, thanks to the integration of RES, can lead to a net plus target, with the building exceeding its average annual electricity demand.

Analysis of Smoke Control System Performance of High-Rise Multifamily Residential Buildings Using Transient Simulation

In Korea, the general floor plan structure of multifamily residential buildings is such that the vestibules of stairs and fire service-access elevators are typically used together. The lobby of the emergency elevator faces the vestibules of the fire service-access elevators. The smoke control system supplies air for pressurization, and the inlet air discharge device for the exhaust can be exempted from this system. In a 49-story multifamily residential buildings with this structure, the smoke control system is operated at an outside temperature of −10 ℃ and indoor temperature of 20 ℃, and the fire room door is open. The possibility of the vertical spread of smoke owing to changes in the open areas of windows and escape elevator doors was analyzed. When the windows are closed, the vertical spread of smoke through the emergency elevator shaft and staircase may occur under both upper and lower fire conditions of the neutral zone. In particular, the flow path through the emergency elevator door is the main vertical spread path in the case of a fire below the neutral zone.

Material intensity and embodied CO2 benchmark for reinforced concrete structures in Brazil

Cement and steel production significantly contribute to global CO2 emissions, with reinforced concrete structures accounting for a substantial portion. Therefore, optimizing the structural design helps reduce material and carbon intensity. However, industry-based benchmarks for material and carbon intensity of structures are scarce and lack transparency. This study fills this gap by analyzing detailed industry data derived from construction designs of 53 reinforced concrete structures for multifamily residential buildings in Brazil and assessing their cradle-to-gate material intensity and embodied CO2 emissions. The findings revealed significant variations in the usage of steel (70–159 kg/m³) and concrete (0.17–0.29 m³/m2). The quantity of structural materials ranged from 418 to 731 kg/m2, and the embodied CO2 ranged from 35 to 140 kg CO2/m2, including the variability in CO2 emissions during material production. Building height is the primary geometric parameter that determined material intensity and embodied CO2, particularly for columns. However, structural materials quantity varies considerably among buildings with the same number of stories, suggesting the presence of additional design parameters influencing material intensity. The results emphasize the role of designers in promoting decarbonization through dematerialization. Also, selecting the right material supplier is important as, on average, differences between manufacturers corresponds to a difference of 38 kg CO2/m2 in structural embodied CO2. Selecting low-carbon material suppliers and employing structural design benchmarking practices can efficiently reduce the embodied carbon of reinforced concrete structures.

Radiators Adjustment in Multi-Family Residential Buildings—An Analysis Based on Data from Heat Meters

Energy is consumed in buildings through the use of various types of energy systems, which are controlled by the occupants via provided interfaces. The quality of this control should be verified to improve the efficiency of the systems and for the comfort of the occupants. In the case of residential buildings, due to privacy reasons, it is problematic to directly monitor human–building interactions using sensors installed in dwellings. However, data from increasingly common smart meters are easily available. In this paper, the potential use of data from heat meters is explored for the analysis of occupant interactions with space-heating (SH) systems. A pilot study is conducted based on a one-year set of daily data from 101 dwellings. First, the identification of an indoor temperature and a strategy for thermostatic radiator valve (TRV) adjustments for all the investigated dwellings is presented. Second, the performed analysis suggests that 96% of the households did not use the automatic adjustment function of the TRVs since adjustments using the on–off mode were the most common, which could be empirical evidence for Kempton’s theory on mental models of home heating controls. The reasons for this could be the weakness of the TRV as an SH interface and the technical specificity of the analyzed SH (its supply temperature). The preliminary investigation confirms the potential of the proposed methodology, but further research is needed.

Water Heating Systems Performance in Multi-Family Residential Buildings in Brazil

The performance of water heating systems must be evaluated considering energy consumption and efficiency in storing and distributing hot water, together with building and climate characteristics. This work aims to analyse the performance of different water heating systems compared to electric showers, which are widely used in Brazil. Systems with individual gas heaters and solar heaters with electric backup and gas backup were analysed in multi-family buildings. In addition, the influence of thermal insulation of hot water pipes was verified. The analyses were conducted using the EnergyPlus programme, considering three Brazilian cities with different climates: Curitiba, Brasília, and Belém. The results showed that solar heaters are a low primary energy consumption alternative, especially if combined with gas heaters. However, electric showers are the most efficient option for larger buildings and cold-climate cities, where thermal losses in distribution are more significant. Monthly, an electric shower can save up to 1.82 kWh/m2 of electricity compared to a solar heating system with an electric backup. The insulation has a limited influence on the performance of short-length pipes (temperature difference less than 0.3 °C in the instantaneous gas system). For longer pipes, the absence of insulation significantly reduces the shower temperature (up to 2.47 °C in solar heating systems), mainly in cold-climate locations. It is concluded that the most suitable water heating system should be determined according to the climate and characteristics of the buildings, such as the size and length of the pipe.

Analysis of Measured CO2 Levels through Long-Term Monitoring in Renovated Multifamily Buildings: A Common Case

The purpose of this study was to analyze the indoor air quality, in particular, the CO2 level, in a real environment, within 16 apartments located in the municipality of Zalău, Romania, in five recently renovated multifamily buildings in which families live under normal conditions. Long-term monitoring was undertaken for 4.5 months, during the heating season of 2022–2023. A representative microclimate perspective was analyzed: the median value of the time fraction, which exceeded the Indoor Environment Quality Category I (IEQcat I) threshold for adults’ bedrooms was 82.30%. For children’s bedrooms, it was 75.65%, while for living rooms, it was 58.78%. When considering IEQcat IV, it was identified that for the bedrooms, the time fraction for which the threshold values were exceeded was still significant (median value of 45.37% for adults’ bedrooms and 50.14% for children’s bedrooms). Even if the indoor thermal comfort conditions increased, it was found that for almost half of the time, the bedrooms did not provide a health-safe indoor environment for the occupants due to inadequate ventilation, exceeding the health threshold values. Thus, it was identified that the ventilation of buildings is a key issue within the renovation process and, currently, is not properly undertaken for the mass renovation of existing multifamily residential buildings.

Comparison of calculation and consumption methods for determining Energy Performance Certificates (EPC) in the case of multi-family residential buildings in Poland (Central-Eastern Europe)

The calculation method and the consumption method are used to award Energy Performance Certificates (EPC), in accordance with the Energy Performance of Buildings Directive (EPBD) 2010/31/EU with revisions. The calculation method can be used for any type of building, regardless of the type of heat source. A good knowledge of the building is required (architectural and construction documentation, inventory of the building). The consumption method can be used only in buildings with heat and gas meters. It is not necessary to have detailed information about the building. However, this method is not applicable to offices, hotels, or production buildings with periodic breaks in heating and hot water consumption. Here, we apply the calculation method and the consumption method to analyse 15 multi-family residential buildings located in Poland (Central-Eastern Europe). Both methods gave similar values. Using the consumption method the energy indicators were slightly lower than using calculation method (on average, the results differed by approx. 14–17%). The consumption method provides a useful alternative to the calculation method, and can be tested by the scientific and expert community in other countries where it has not yet been implemented.

Energy retrofit alternatives for three apartment buildings in Kosovo

AbstractThe need to decrease energy use represents a challenge particularly in developing countries, including Kosovo, considering the unsustainable, insufficient, and inconsistent energy supply. This contribution presents a simplified yet comprehensive approach to evaluate the energy performance improvement potential of three selected multi-family residential buildings using building energy models generated from calibrated and simplified input parameters. To this end, alternative retrofit measures were tested via a simulation-based parametric study. The energy benefit of each retrofit alternative was estimated and analyzed. Results are expected to provide valuable information towards outlining design guidelines for energy-efficient residential buildings in Kosovo.

The types of spatial adaptability based on user preferences of low-income apartments in erbil city

Spatial adaptability is the ability of floor plans to adapt to families' changing needs and requirements over time. Apartment floor plans that are not designed according to the user's preferences cannot meet his or her changing needs over time. So, an adaptable apartment floor plan is considered a desirable alternative that can provide various solutions to households' changing spatial needs in the present and the future. Future low-income apartment designs will be more effective if users select the most appropriate types of floor plan adaptability for their needs and culture. The aim of this study is to identify user preferences for the types of adaptability of floor plans and assess the adaptability capacity of low-income apartment floor plans based on those preferences. Based on the research criteria, six low-income multi-family residential buildings in Erbil City were chosen as case studies. The questionnaire was conducted through face-to-face interviews with 363 participants. The study used mixed methodologies, including a quantitative questionnaire survey and a qualitative case study analysis method, to answer the research questions. This study concluded that users did not prefer all the types of spatial adaptability; they preferred the ones that most suited their needs, lifestyles, and preferences. Low-income apartment floor plans didn’t support user preferences, and residents of low-income apartments in Erbil City could not adapt their apartment floor plans according to their preferences. According to the findings of this study, there should be a greater emphasis on the future design of low-income apartment floor plans in order to meet the changing space needs and requirements of families. This study can help architects and policymakers improve housing quality in Erbil City by considering user preferences for space adaptation when designing low-income apartment floor plans in the future.