Multi-family Buildings Research Articles

다가구매입임대주택 거주자를 위한 주거서비스와 공가 활용 방안

Background/Objectives: Public rental multi-family housing, in general, shows low resident satisfaction, and high incidence of empty houses. This study aims to identify the architectural characteristics of public rental multi-family buildings with empty houses and examine residents’ use and demand of community facilities, to suggest ways to remodel empty houses into community facilities for improved residential services. Methods: Nine public rental multi-family buildings with empty houses in Cheongju City were spot surveyed for physical characteristics, and 26 residents answered online and offline questionnaires on housing environment satisfaction, demand of housing services, and usage of empty houses. Frequencies, percentages, and averages were calculated using SPSS. Results: 1) Public rental multi-family buildings with empty houses show various problems, including conflicts among residents caused by insufficient parking space and waste disposal, and undesirable noise, ventilation, and sunlight. 2) The overall housing environment satisfaction level of residents was lower than 3.0 median points. 3) Among residents’ housing service needs, fitness center with training machines, ranked the highest, followed by a common garage. Conclusion/Implications: 1) To lower resident conflicts, it is necessary to establish living regulations through continuous communication among residents, and secure parking space and separate garbage dumping space in the surrounding empty areas. 2) It is necessary to remodel the empty houses in public rental multi-family buildings into spaces for differentiated community facilities and residential service spaces.

Credibility of feeling versus image of a place

The perception of architecture is realized as a result of the metaphorical travel of the observer through the designed space, it is a specific reading of space at different levels of feeling. Designing is a scenario, user manual for those who are in this space. The aim was to examine the living space of two original authors concepts of multi-family residential buildings, based on the adopted architectural criteria, in terms of the credibility of feeling of the architecture of the living space. Moreover adopted criteria determines the quality of activities determining the condition of living. The method of logical argumentation was adopted for the research, interpreting selected original examples in order to conduct a critical analysis of the existing solutions. The result is a graphic record of repeatable floor plans of multi-family residential buildings, showing a veristic or virtual space as a factor of credibility of living. The conclusions present the method of shaping the architecture space in post-designed multi-family residential buildings based on the criterion of the credibility of feeling in the context of the image of a place in space.

Multi-family living space expressing simultaneous and linear way of living

Factors that affect the way activities are executed tend to determine the condition of living and the model of performing actions. Such factors include the transformability or non-transformability of the structure as well as mobility or stability. These factors have a significant impact on the model of the house and the model of living as a state in a living space. A consequence of the transformability and non-transformability of space forms a simultaneous or a linear (chronological) model of activities that determine the condition of living. The study examines the space of the apartment within a multi-family residential building included in the residential and service complex at Grunwaldzki Square in Wrocław, designed by Jadwiga Grabowska-Hawrylak, using the adopted criteria. The aim was to examine the space in terms of the adopted architectural criteria to perform activities that determine the condition of living based on a simultaneous and a linear (chronological) model. The method of logical argumentation was applied in the research with the purpose of interpreting the selected example. This was performed to achieve the goal by applying a set of planned research criteria. The outcome takes the form of a graphic record of the floor plans of apartments based on two possible cases of shaping the living space. The conclusions show a living space expressing a simultaneous and linear way of performing activities that determine the condition of living.

3D spatial dispersion of particulate matter and gaseous pollutants on a university campus in the center of an urban agglomeration

Urban areas are anthropogenic sources of particulate matter emissions and gaseous pollutants, which can have negative impacts on human health and life. In this study, we examined an area of 0.42 km2in the city center of Łódź/central Poland (Central-Eastern Europe), to identify the likely sources of pollutant emissions. Field measurements were conducted in 2021. The analyzed area consists primarily of a university campus (Lodz University of Technology), with buildings from the nineteenth, twentieth, and twenty-first centuries at heights of 10–40 m. The spatial distributions of PM10 and PM2.5 were analyzed, as well as the spatial distributions of gaseous H2S and VOCs (from 0 to 40 m above ground level). The analyses took into account the impact of seasonal changes (winter, summer, and autumn periods) on air quality. Air quality was assessed in relation to the limit values. The measurements and analysis confirmed the complexity of the spread of pollutants in dense urban developments. Zones of accumulation of particulate matter and gaseous pollutants in leeward and windward spaces were found. It was found that the probable source of air pollution may be multi-family buildings with individual heating systems and an industrial plant located in the vicinity of the analysis area.

Lowering water level in an excavation for a multi-family residential building in urban development

The paper concerns lowering water level in excavations for residential buildings in a dense urban development. The construction and protection of excavation walls as well as the methods of lowering the water level and its impact on the surroundings were discussed. An excavation dewatering system is presented on the example of a multi-family residential building with one underground floor, built in dense urban development. The excavation executed in the sandy subsoil below the groundwater level and encased with walls made of steel sheet piles was analysed. Two concepts of lowering the water level in the excavation were considered: the first with use of a wellpoint system, the second with use of a well with pumps. The conducted calculations showed that when using a wellpoint system to lower the water level in the excavation for analysed multi-family residential building, a system consisting of 260 wellpoints with a spacing of 1.0 m should be made. The efficiency of a single wellpoint is 12.25 m3·d–1, and the efficiency of the entire installation is 3,185.69 m3·d–1. When draining the wells, a system consisting of 9 wells should be made, with a unit capacity of 375.58 m3·d–1 and efficiency of the total installation 3,380.22 m3·d–1.

A goal-framing perspective on the important aspects of energy-efficient multifamily buildings.

The growth of Sweden’s urban population necessitates new approaches for increasing the sustainability and energy efficiency of multifamily buildings. The development of such approaches will require a holistic and integrated understanding of the factors driving the decision making of both professionals who design buildings and end-users who live in them. This paper, therefore, uses the goal framing theory to determine which aspects of multifamily buildings are considered important by these two groups of actors. An empirical study based on semi-structured interviews with professionals involved in building design and development (project developers, housing company representatives, architects, and engineers; N = 15) was conducted to identify goals affecting the choices made during building design and development. In parallel, a questionnaire survey of building end-users (N = 61) was conducted to determine which factors guided their choice of dwelling. It was found that professionals’ design choices were primarily governed by normative goals relating to environmental benefits but were also influenced by the other goals. These included gain goals relating to budgetary constraints and keeping the building’s operational and maintenance costs low. Hedonic goals were also important; some design choices were made with the aim of providing pleasant, comfortable, and convenient living environments, or of giving the buildings a distinct aesthetic or some other special features. By comparing the professionals’ responses to the end-user surveys, it was found that the two groups had similar views concerning gain goals; both considered it important for apartments to be affordable and easy to maintain. However, their views on hedonic and normative goals differed markedly. The professionals sought to strike an optimal balance between different related aspects, whereas end-users placed greater importance on aspects relating to hedonic and gain goals when choosing dwellings. The findings provide a basis for constructive discussions on building design and development, and the scope for creating buildings that encourage end-users to adopt sustainable living practices while also satisfying their needs and preferences.

Dilution of airborne contaminants from through-wall exhausts located on the side of multi-family residential buildings

Several models exist for predicting dilution from large rooftop exhausts, but their validity has not been assessed for horizontally directed through-wall exhausts such as those that often exist in new multi-family residential construction. Separation distances derived from rules of thumb or simplified versions of these models are prescribed in ventilation standards, but their appropriateness has not been assessed and they are sometimes difficult to achieve in practice. In order to provide more justifiable separation distances, we conducted a series of wind tunnel experiments and computational fluid dynamics (CFD) simulations measuring dilution of a horizontally-directed exhaust from a test building. We then compared these measurements to existing models and assessed the models’ validity for this situation. Lastly, we gathered dilution criteria for several contaminants of interest and used wind tunnel and CFD results along with published emission rates to specify a separation distance that is likely to result in acceptable air quality at neighboring intakes. Results show that mitigation of chronic health concerns from cooking, and smoking in dwelling units, as well as odor concerns from bathrooms, can likely be achieved with separation distances of 5 feet or less. To prevent irritation from smoking in neighboring units, a separation distance of 10 feet is recommended. We did not find that furnace exhaust can be diluted sufficiently with separation distances that are feasible on multi-family buildings.

A Case Study of Mapping the Heating Storage Capacity in a Multifamily Building within a District Heating Network in Mid-Sweden

The building sector accounts for a third of the total energy use in Sweden, and district heating provides half of the heating needs. The peak demand loads within a district heating network occur both regularly and irregularly and impose a burden on the energy company to fulfill the demand, often by using more expensive and less environmentally friendly resources (e.g., fossil fuels) instead of the waste heat from industry or biofuels. Heat storage during hours of less demand and prior to colder periods can be used for load management and sustainable planning of energy supply, as well as reduction of total greenhouse gas emissions. Thus, heat supply to the building can be lowered temporarily during the peak power period to utilize the stored thermal energy within the building thermal inertia. The use of indoor temperature decay and the delivery of heating power to a multifamily building are studied here, and heating storage capacity and thermal inertia are calculated. During the performed decay test, the energy supply was estimated to be reduced by 61% for 5 h, which resulted in only a 0.3 °C temperature decay. Therefore, the suggested method can shave eventual peaks in supplied heat with minimal influence on the thermal comfort.

A comparison of building system parameters between affordable and market-rate housing in New York City

Low-income households in the United States experience higher than average energy burdens (defined as the proportion of household income spent on energy utilities), and many of these households struggle to simultaneously pay for rent, energy, and basic household necessities. The analysis presented here examines whether the underlying characteristics of buildings and their energy systems could contribute to this disparity for affordable housing residents in New York City. It combines an energy audit dataset of 7,328 multifamily buildings with a database of properties receiving local, state, or federal housing subsidies. The results of this analysis indicate that the building-level installed equipment in large (greater than 50,000 square feet) affordable housing buildings in New York City is more efficient than that in market-rate buildings, but this trend largely disappears when considering overall building characteristics, such as location, size, or age. Significant differences in the types of systems installed in affordable and market-rate housing are also observed, as well as the types of energy efficiency recommendations made by energy auditors. However, these latter data were not normalized by building system characteristics, as that analysis is much more difficult to interpret for categorical data such as heating system type. These findings indicate that retrofit policies and building performance standards focused on affordable housing will likely need to account for underlying differences in building characteristics between affordable and market-rate housing to achieve intended impacts.

Statistical Analysis of the Variability of Energy Efficiency Indicators for a Multi-Family Residential Building

During the building design phase, a lot of attention is paid to the thermal properties of the external envelopes. New regulations are introduced to improve energy efficiency of a building and impose a reduction of the overall heat transfer coefficient; meanwhile, this efficiency is more influenced by the efficiency of the heating system and the type of fuels used. This article presents a complex analysis including the impact of: heat transfer coefficient of the envelope, efficiency of building service systems, the type of energy source, and the fuel. The analysis was based on the results of simulation tests obtained for an exemplary multi-family residential building located in Poland that is not equipped with a cooling system. The conducted calculations gave quantitative evaluation of the influence of particular parameters on building energy performance and showed that the decrease of heat transfer coefficient of building boundaries, in accordance to the Polish regulation for 2017 and 2021, gave only 11% of reduction on usable energy demand index. On the other hand, it was found that modification of the heating system and heat source can significantly influence the values of the final and primary energy consumption at the level of 70%. The application of heat pumps has a greater influence on the final and primary energy consumption for heating indices than other parameters, such as the building’s envelopes.

Large Air-to-Water Heat Pumps for Fuel-Boiler Substitution in Non-Retrofitted Multi-Family Buildings—Energy Performance, CO2 Savings, and Lessons Learned in Actual Conditions of Use

The use of air source heat pumps (ASHP) in the specific context of existing multi-family buildings (MFB) represents an important challenge, especially in terms of performance and technical constraints in real conditions of use. This study concerns the actual performance of two non-retrofitted MFB (4047 and 7563 m2), whose original fossil heat supply was replaced by a centralized monovalent (2 × 156 kW) and hybrid (6 × 34 kW) ASHP system for space heating and domestic hot water. Based on a detailed monitoring campaign covering two years of operation, it can be concluded that both systems are able to supply the required temperature and cover the entire heat demand. By closely following up these pilot projects, constraints linked to integration and operation were identified. Optimization measures allowed us to increase the COP of the monovalent system (from 1.3 up to 3.4, with an optimized SPF of 2.3) and to raise the HP share of the hybrid system (from 50% to 67%, with an optimized SPF of 2.3). Both systems offer major progress in terms of CO2 savings (92% and 68%) and increased renewable energy share (75% and 43%), considering the hourly CO2 content of the Swiss electricity mix.

Techno-economic approach for optimum solar assisted ground source heat pump integration in buildings

Two-step approach for optimum solar assisted ground source heat pump integration in buildings is proposed. At the first step energy targeting based on dynamic pinch analysis allows to target the energy and optimum equipment size according to buildings’ dynamic demands, and as a result, several energy efficient daily design candidates are extracted. At the second step of the proposed approach, a final design working for the whole year is selected among all the candidates by computing the total annual cost (TAC). A special algorithm is proposed to compute the yearly average energy and capital cost penalty for complementary hot/cold utilities in order to adapt the daily designs to the overall year design. As an objective function, TAC is defined for a 20-year lifetime design. Moreover, the TAC of several daily optimum designs (DOD) based on different scenarios are investigated for a multifamily test building. In the context of Canadian market, it is illustrated that the choice of the overall year integration design depends mainly on the electricity cost. For example, with Quebec electricity cost (i.e., 0.073 CAD/kWh), the DOD of September is optimal for the whole year, where there is no need for vertical ground heat exchangers. However, if Canadian average electricity cost (i.e., 0.147 CAD/kWh) is considered, the DOD of March is optimal for the whole year, with a vertical ground heat exchanger depth of 200 m. The DOD of September and March can reduce building’s annual electricity consumption by 55.9% and 79.2%, respectively.

Field Measurement of Central CO2 Heat Pump Water Heater for Multifamily Retrofit

Domestic hot water heating of multifamily buildings accounts for a substantial portion of the energy load of existing buildings. This load is made up of both the energy required to produce hot water and the energy needed to maintain the temperature of the heated water within a building’s distribution piping so that heat can be promptly delivered to building occupants as needed. Properly designed heat pump water heater (HPWH) systems have the ability to improve efficiency in both water heating and temperature control operations. Further, CO2 heat pump technology reflects a shift away from traditional refrigerants and toward refrigerants with low global warming potential (GWP). In this paper’s case study, a design consisting of multiple CO2 heat pump water heaters (commonly used in single-family homes) with a novel “swing tank” was proposed to meet the demand for domestic hot water heating and recirculation loop temperature maintenance. The proposed design was applied to the retrofit of a 60-unit, low-rise, multi-family building located in the Pacific Northwest of the United States. The purpose of this paper is to verify the performance of the system including the proposed “swing tank” in a centralized SHW system using CO2 HPWH. It also provides practical information and lessons learned from the retrofit project. Long-term monitoring data showed that the system had a coefficient of performance (COP) of three or greater and provided an average of 20 gallons of hot water per day per apartment. The results of this work indicate that residential-scale CO2 HPWH equipment and a “swing tank” design can efficiently provide domestic hot water heating and temperature maintenance for mid-sized multifamily buildings.

Virtual Net-Metering Option for Bangladesh: An Opportunity for Another Solar Boom like Solar Home System Program

This study explores the virtual net-metering (VNM) option for enabling inclusive investment opportunities in renewable energy for self-consumption in Bangladesh. It focuses on consumers, such as households and businesses in multi-family and multi-story buildings, who cannot participate in traditional net-metering policy due to technical and space constraints. The study adopted the classical socket parity method to identify suitable consumers for VNM. Then it determined the consumer benefits of using VNM by calculating the net present cost (NPC) and discounted payback period. The results reveal that several consumer categories can significantly save on electricity costs through VNM. For example, commercial consumers can save more than 50% of their electricity bills by investing in a VNM-enabled remote solar power plant with a discounted payback period of fewer than six years. The discussion articulates more comprehensive benefits of VNM. It addresses challenges for renewable energy development by identifying local opportunities. Therefore, this research can help initiate policy dialogues and create momentum for citizen investments in the energy transition. The proposed approach can also be used to analyze the economic feasibility and potential of VNM in other countries.

Optimization of balcony’s glazed enclosure with spectrally selective coatings regarding heating demand and thermal comfort in a multifamily building

Optimization of balcony’s glazed enclosure with spectrally selective coatings regarding heating demand and thermal comfort in a multifamily building

Social Housing Life Cycle Management: Workflow for the Enhancement of Digital Management Based on Building Information Modelling (BIM)

The management of the life cycle of large publicly owned social housing complexes requires a large amount of human and technological resources, the optimization of which is a desirable and shared objective. This article proposes a workflow for the enhancement of these management processes based on BIM (Building Information Modelling), a methodology capable of integrating architectural information into a three-dimensional graphic model. The proposed workflow defines the basic characteristics of the BIM model oriented toward sustainable building management and its relationship with the key moments of its life cycle. It also analyzes the architectural information associated with the models and determines which parameters are optimal for their completion from the BIM models in terms of reliability, auditability, and automation. For this purpose, a case study has been developed for a multifamily residential building in Malaga (Spain), owned by the Andalusian Housing and Rehabilitation Agency AVRA, a public agency that manages a housing stock of more than 70,000 dwellings.

Motivators and impediments to seismic retrofit implementation for wood-frame soft-story buildings: A case study in California.

Motivating property owners to mitigate seismic risks for existing buildings is a major challenge for many earthquake-prone regions. This article identifies primary factors that may affect the adoption of seismic retrofit by owners of commercial and residential buildings, assesses the influence of economic, social, regulatory, and individual factors on retrofit implementation in three California cities, and discusses potential approaches to promoting seismic retrofits. Data for three retrofit programs are utilized to create predictive models for retrofit probability. The results suggest that retrofit probability for multifamily residential buildings may increase with building height, median housing value, educational attainment, and population density in the neighborhood, but may decrease with building age, building size, land value, and housing vacancy rate in the neighborhood. The retrofit decision for commercial buildings is strongly correlated with the number of stories and rooms, land value, vacancy rate, and population density, while the retrofit decision for residential buildings is highly associated with building age, number of rooms, land value, median housing value, median contract rent, and educational attainment. Overall, promoting seismic retrofits requires careful consideration of different motivators and impediments to owner's retrofit actions for commercial and residential buildings, and for older, taller, larger buildings, which tend to be more vulnerable but are associated with higher retrofit costs. In addition, neighborhood characteristics including median housing value and vacancy rate may be strong indicators of the retrofit probability among building clusters.

Assessment of solar photovoltaics potential installation into multi-family building’s envelope in Amman, Jordan

Assessment of solar photovoltaics potential installation into multi-family building’s envelope in Amman, Jordan

The role of solar cooling for nearly zero energy multifamily buildings: Performance analysis across different climates

The building sector has great potential for contributing to the 2030 EU goals of decreasing greenhouse gas emissions and increasing production from renewable sources. This is even more important considering the increasing cooling energy needs. Among the available technologies, solar cooling (SC) represents a good alternative to traditional electric chillers. However, its use in residential buildings is still limited.The aim of this paper is to analyse the potential of solar cooling system in multi-family buildings. A dynamic model of a complete SC system with auxiliary components was developed in TRNSYS to meet the energy demand of a representative nearly zero energy multi-family building in Italy. The performance of different system design alternatives was analysed in eight different climates with special focus on energy storages.The results show how solar cooling should be optimally designed and provide quantification of achievable renewable energy ratios and related costs in the different climates.

Electrifying High-Efficiency Future Communities: Impact on Energy, Emissions, and Grid

To combat climate change and meet decarbonization goals, the building sector is improving energy efficiency and electrifying end uses to reduce carbon emissions from fossil fuels. All-electric buildings are becoming a trend among new constructions, introducing opportunities for decarbonization but also technical challenges and research gaps. For instance, further investigation is needed to understand how the adoption of energy efficiency measures (EEMs) and distributed energy resources (DERs) in all-electric communities would affect energy consumption, carbon emissions, and grid planning. This paper presents a case study of a mixed-use, all-electric community located in Denver, Colorado. We use URBANopt™, a physics-based urban energy modeling platform to model the community and then evaluate the impact of EEMs and DERs (i.e., photovoltaics [PV], electric vehicles [EVs], and batteries) on the community’s energy usage, carbon emissions, and peak demand. The results show that adding EEMs and PV led to both energy consumption and carbon emissions reductions across all building types. However, we saw fairly limited impact of EEMs and PV on buildings’ peak demand in our case. Additionally, due to overnight EV charging activities and higher grid carbon intensity at night, the carbon emissions in multifamily buildings have a noticeable increase compared to scenarios without vehicles. Finally, the addition of batteries helped reduce peak demand by 11%–29%. The modeling workflow and evaluation methods can be applied to similar communities to evaluate their performance and the effect of integrating EEMs and DERs.