Multi-family Apartment Buildings Research Articles

Neighborhood renewal at stake: feedback on speculative redevelopment in setif, algeria

Introduction: This paper examines a type of real estate speculation that plays a key role in urban redevelopment, characterized by densification and unaffordability. Purpose of the study: The study aims to analyze how pericentral housing in the form of a garden city is being subjected to incremental renewal in the historic core of Setif, Algeria. It reflects on UN Sustainable Development Goal #11, Sustainable Cities and Communities, in terms of relationships between housing densification, loss of green spaces, and socio-economic implications. Methods: We used a survey strategy based on observation and a sustainability indicator questionnaire as quantitative sources as well as semi-structured interviews and focus groups as qualitative sources. Results: Our study revealed that the typological shift from single-family houses to multi-family apartment buildings is not driven by changing housing preferences, but rather by a profit-oriented land-use strategy. This shift has led to affordability issues and gentrification, which in turn challenge socioeconomic cohesion. The process of densification and apartmentization causes the erosion of the architectural character of buildings and the physical characteristics of the neighborhood. The study emphasizes the importance of proactive, participatory, and inclusive methods in urban planning and management for a bottom-up approach to counteract speculative neighborhood renewal driven by liberal policies. It proposes a densification toolkit to promote the principles expressed in the sustainable development goals (SDGs).

Finnish energy renovation subsidies in multifamily apartment buildings: Lessons learnt and best practices

This study analysed renovation measures implemented with ARA renovation subsidy in Finland in multifamily apartment buildings. Measured energy data was used to calibrate the energy simulation model of the most typical renovated building from the 1970 s. For the reference building, a comprehensive set of renovation packages were applied to assess the performance of ARA grants. It was noticed that official energy performance certificates (EPC) overestimated before the renovation energy use as well as energy saving by a factor of almost 2. It was notable that in calculated EPCs, after renovation, EP-value was higher than before renovation, EP-value based on measured energy use. The main reasons for faulty energy calculations were strong overestimations in the building leakage rate and ventilation airflow rate. Renovation packages reduced EP-value by 8 % to 27 %, including lighting and appliances. Those using district heat resulted in a small increase in electricity with a flat duration curve, but the combined ground source and exhaust air heat pump showed the highest peak electricity power increase by factor 6. Exhaust air heat pump, window replacement and photovoltaic were the most cost-effective options, while packages with additional insulation faced considerably higher costs than the sum of ARA support and monthly savings could cover bank loans; thus, ARA support was clearly too small to support deep renovation. The need to improve the accuracy of EPCs in assessing energy performance to facilitate more effective financial support was a finding that can be important for any support scheme to secure the necessary funding for renovation.

Understanding the Challenges of Implementing Green Roofs in Multi-Family Apartment Buildings: A Case Study in Khulna

Green roofs are widely recognized for their multifaceted benefits to the environment, economy, and society, constituting the fundamental pillars of sustainability. These roofs contribute to the enhancement of bio-physical diversity, provision of food resources, regulation of temperature and rainfall-runoff patterns, creation of wildlife habitats, and augmentation of aesthetic and recreational value. While Bangladesh, with its favourable climatic conditions and rapid urbanization, possesses immense potential for harnessing the advantages of green roofs, their adoption remains limited in both research and practical applications within the country. Addressing this research gap, the present study aims to investigate the barriers impeding the implementation of green roofs in existing or new multi-family apartment buildings, focusing specifically on the city of Khulna. Through a combination of case studies and a comprehensive questionnaire survey administered to diverse stakeholders including apartment dwellers/owners, architects, developers, and government officials with varying levels of expertise, this research sheds light on the obstacles hindering Green Roof Implementation (GRI). The identified barriers encompass a lack of governmental policies, inadequate technological advancements, inaccurate estimation of economic benefits, and individual resistance. In light of the perspectives of various GRI stakeholders, strategic proposals encompassing policy, technical, economic, and social dimensions are presented to surmount these barriers. The outcomes of this study contribute to the dissemination of knowledge pertaining to the impediments to GRI implementation, thereby inspiring further research endeavours and enabling decision-makers to formulate robust policies facilitating the widespread adoption of green roofs.

Evaluation of increased electricity production when cooling solar panels

A municipal housing company located in the south of Sweden has energy renovated several buildings with a total of 380 apartments to meet today’s energy standards. Several energy efficient technologies and solutions were implemented and the energy consumption for these buildings were lowered by 50%. One of the buildings functions as a demonstration building for innovative solutions such as low temperature district heating, waste water heat recovery, and solar photovoltaic and thermal (PVT) panels. The solar PVT panels are cooled down with the main purpose to increase the electricity production. The cooling medium for these panels is circulated through two bedrock boreholes to dissipate the collected heat. The heat from the boreholes is then used for an electric heat pump to produce heat to send to the local district heating company. The electricity produced is primarily used in the building. The objective of this paper is to assess the electricity production from real-life outdoor Photovoltaic-thermal (PVT) plant. The plant was installed on the roof top of an energy renovated multi-family apartment building located in the south of Sweden. The cooling of the panels were turned on and off to assess if the electricity production would increase or not. The electricity production did not increase when the cooling was applied. The temperature measuring equipment which was installed at the wrong position and was supposed to measure the temperature at the back of the PVT is needed to compare the efficiency of the PVT plant and draw further conclusions.

Social Cohesion and Neighbor Interactions within Multifamily Apartment Buildings: Challenges of COVID-19 and Directions of Action

Relations among neighbors are a key indicator of the strength of a local social community, contribute to social cohesion and are an important factor in achieving a higher level of social sustainability. On the other hand, the environment in which people live plays an important role in encouraging social contacts and developing relationships between people. In order to establish social interactions between neighbors within a multifamily apartment building (MFAB), it is necessary to provide adequate spaces for communication between residents. This was especially emphasized during the mobility restrictions caused by COVID-19, although this necessity is permanent. This paper analyzes the influence of the physical characteristics of common spaces in MFABs on the quality and intensity of contacts among residents of MFABs in the City of Niš, Serbia. In order to determine the current quality of these spaces as a physical framework for interactions among residents and to identify the wishes of users regarding interactions with neighbors in these spaces before and during COVID-19 pandemic restrictions, a survey was conducted. The analysis of the survey results and numerous examples of housing design led to (1) the formation of guidelines for future designs of MFABs and (2) recommendations for redefining the standards regulating the field of housing construction in the region, both applicable during the period of the pandemic and after it.

An Overview: PM2.5 Concentration Levels in Urban Residential Buildings during the Past Two Decades

The public has become increasingly aware of the critical effect of fine particle matter (PM2.5) on indoor air quality. Urban residents spend more than half of their time at home. Therefore, monitoring PM2.5 concentrations in residential settings is critical. This paper presents a review of studies on PM2.5 concentrations in the living rooms of urban residential buildings. We included studies measuring indoor PM2.5 concentrations across different regions worldwide and then summarized the measured concentrations. Factors contributing to differences in indoor concentrations were identified and explained. The review results revealed that most of the included studies were conducted in Asia and in Europe, and some were conducted in North America and Africa. Moreover, the mean daily PM2.5 concentration ranged from 17.3 µg m-3 in North America to 68.6 µg m-3 in Asia. Factors influencing PM2.5 concentrations were as follows: indoor activities, ventilation type and air cleaner (AC) use, building type and performance, ambient environment and season. Smoking and cooking considerably increased PM2.5 concentrations in the living rooms, even in measurements conducted over a short time. The use of an AC could reduce indoor PM2.5 concentration in an average of 60%. Regarding building type, PM2.5 concentration in multifamily apartment buildings had higher PM2.5 concentrations than did single-room residences. Moreover, severe outdoor particle pollution increased indoor PM2.5 concentrations by up to 142% in low-energy residential buildings.

Cost-related analysis of implementing energy-efficient retrofit measures in the residential building sector of a middle-income country – A case study of Bosnia and Herzegovina

This study presents an in-depth analysis of the cost structure when planning EE retrofit measures in the residential sector in Bosnia and Herzegovina. The analysis showed that implementing EE retrofit measures would result in substantial energy savings in single-family houses, however, the specific cost of implementing EE retrofit measures per resident for single-family houses is on average 2.8 times higher than for the other three categories; multi-family houses, apartment buildings, and high-rise buildings. When considering the ratio between the investment costs and GDP per capita showed that the citizens in Bosnia and Herzegovina have four times lower ability to finance EE retrofit measures compared to three other representatives EU members and therefore government subsidy schemes may be inevitable for successfully implementing EE retrofit strategies. The general conclusion based on the cost-effective analysis is that EE retrofit investments, may not be financially viable in single-family houses, multi-family houses, and apartment buildings even if supported by government subsidies due to the very low prices of energy sources (coal and wood) used in these specific building prototypes. On contrary, high-rise buildings, that are mainly driven by natural gas and light distillate fuel oil, show a great EE retrofit-driven profitability in. Looking at the financial assessment outcomes, the most significant benefits are mainly related to retrofit scenario that accounts for improvement in the external wall insulation, window glazing, and improving the heating station efficiency. Looking at the carbon emission outcomes, the most significant benefits in reducing the relative and averaged CO2 emission are strongly related to replacing the existing partly coal-burned furnaces (80% firewood + 20 % coal) in single-family houses with exclusive firewood fueled heating systems. This measure may have an enormous impact on reducing the CO2 emission from single-family houses (minimum 83.1 %), which cover 93.1 % of the total residential building stock in Bosnia and Herzegovina. This study may benefit low and middle-income governments in their aim to translate potential EE retrofit measures in the residential sector to a nationwide economic energy-saving policy.

An integrated optimization and sensitivity analysis approach to support the life cycle energy trade-off in building design

The building design process plays a central role in efforts to implement energy-efficient practices. However, unilateral design choices based solely on reducing operational energy use can significantly increase a building’s embodied energy and life cycle energy use as there is a trade-off between embodied and operational energy. To support such trade-off problems, multi-objective optimization represents a useful approach that produces a set of optimal solutions from where a solution can then be selected and progressed within the design process. Selecting one solution from the set of optimal solutions can however be a challenging task as each solution has the potential to be chosen as the optimum. Therefore, the purpose of this study was to explore how solutions from a multi-objective optimization approach can be analyzed further to provide information to decision-makers when selecting the optimal design solution. An approach is proposed where the integration of post-optimization sensitivity analysis into a multi-objective optimization approach aims to support decision-makers in analyzing the optimal solutions provided by the optimization process. The applicability of approach is demonstrated using a case of a multifamily apartment building located in Sweden, where the aforementioned trade-off is explored for a set of energy efficiency measures. Thereby, a diverse range of optimal solutions that could result in up to 4520 GJ life cycle energy (LCE) savings relative to the case building’s initial design was initially identified using the multi-objective optimization. These solutions were then subjected to a sensitivity analysis where the results indicated that in general the lowest and highest sensitivity in terms of LCE use belonged to the insulation thicknesses in roof and walls, respectively. Furthermore, the thickness of exterior floor insulation yielded the greatest variation in the sensitivity. The findings of case study indicate that the post-optimization sensitivity analysis can add valuable information that complements the results obtained using a multi-objective optimization approach. Consequently, it can support decision-making on how to progress with the design in terms of what design parameters have a negligible or significant impact on the objectives when they are varied, thus facilitating prioritization.

Calibration of energy simulation model for three buildings in Kosovo

Abstract The energy performance of residential buildings depends on a large number of interrelated factors. The present paper outlines an approach to developing a building thermal simulation model through real-time data and sensitivity analyses. To this end, three existing multi-family apartment buildings in Pristina, Kosovo, were selected. Initially, thermal simulation models were created using multiple data sources. Model outputs were further evaluated via comparison with available and measured data. Consequently, the most influential input parameters were identified and adjusted to calibrate the models. The resulting calibrated models can be deployed to investigate the potential of alternative retrofit measures.

Returns to Scale in Residential Construction: The Marginal Impact of Building Height

AbstractWe estimate the marginal cost and break‐even rent of developing multifamily apartment buildings in the 50 largest cities in the United States using a novel data set of required construction inputs of standardized assemblies. We find nonlinearities in the marginal cost curve at the fourth and eighth stories that directly impact a developer's returns to scale with respect to height. This curve allows us to identify a developer's maximum willingness to pay for land for each building height, which we then compare to existing single‐family land prices to determine whether new multifamily development will occur. The analysis concludes by simulating the impact of height regulations on break‐even rents of new supply. We find that height regulation often has large, negative effects on housing affordability, with increasing magnitudes for more expensive land markets.

Architecture and transformation in Mexico City’s UNAM University Campus

<p>Architecture in permanent transformation is the starting point of this article, focused on the interaction between material and social aspects of a case study on modern Mexican housing, observing the building’s life in relation to its inhabitants. The Multifamily Apartment Building for Teachers (Multifamiliar para maestros), a faculty housing building at the UNAM campus, is a mid-twentieth-century experimental housing project, developed at the beginning of Mexico City´s densification. Today it is registered in UNESCO’s World Heritage Sites. The case study sheds some important insights into the transformations of a spatial modern utopia facing inhabitants' needs. Numerous differences were detected between the original idea behind the building’s architecture and the reality of its users today, revealing not only the ambiguous nature of the building but also problems derived from the country’s accelerated modernization. The results show contrasting approaches of the intermediate space between the building’s conception, and the constant process of becoming a home, where the scope of its habitability is negotiated. </p>

Monitoring and Controlling House Mouse, Mus musculus domesticus, Infestations in Low-Income Multi-Family Dwellings.

Simple SummaryThe house mouse is a very common pest in low-income multi-family residential dwellings. They cause significant property damage and produce allergens that are linked to asthma and allergy. Current mouse management practices in these dwellings are not effective. This study attempted to gain insights into residents’ impressions of house mice, develop more effective mouse detection methods, and evaluate the effectiveness of building-wide mouse management programs. The programs were implemented by researchers for 63 days and the results were monitored for up to 12 months. Significant differences were found in the efficacy of two commercial blank baits for detecting house mouse activity. Chocolate spread was significantly more effective than both commercial blank baits for detecting house mice. Between the two commercial toxic rodent baits tested, FirstStrike® (0.0025% difethialone) was more palatable than Contrac® (0.005% bromadiolone) rodent bait. A building-wide mouse control program resulted in an 87% reduction in mouse activity after three months in two buildings. After 12 months, the number of infestations decreased by 94% in one building, but increased by 26% in another building. Long-term house mouse control requires continuous efforts and the incorporation of multiple strategies.The house mouse, Mus musculus domesticus, is a common pest in multi-family residential apartment buildings. This study was designed to gain insights into residents’ impressions of house mice, develop more effective house mouse detection methods, and evaluate the effectiveness of building-wide house mouse management programs. Two high-rise apartment buildings in New Jersey were selected for this study during 2019–2020. Bait stations with three different non-toxic baits were used to detect house mouse activity. Two rodenticides (FirstStrike®—0.0025% difethialone and Contrac®—0.005% bromadiolone) were applied by researchers over a 63-day period and pest control operations were then returned to pest control contractors for rodent management. There were significant differences in the consumption rates of non-toxic baits and two toxic baits tested. A novel non-toxic bait, chocolate spread, was much more sensitive than the two commercial non-toxic baits for detecting mouse activity. The house mouse management programs resulted in an average 87% reduction in the number of infested apartments after three months. At 12 months, the number of infestations decreased by 94% in one building, but increased by 26% in the second building. Sustainable control of house mouse infestations requires the use of effective monitoring strategies and control programs coupled with preventative measures.

Presence and variability of culturable bioaerosols in three multi-family apartment buildings with different ventilation systems in the Northeastern US.

Bioaerosol concentrations in residential buildings located in the Northeastern US have not been widely studied. Here, in 2011-2015, we studied the presence and seasonal variability of culturable fungi and bacteria in three multi-family apartment buildings and correlated the bioaerosol concentrations with building ventilation system types and environmental parameters. A total of 409 indoor and 86 outdoor samples were taken. Eighty-five percent of investigated apartments had indoor-outdoor (I/O) ratios of culturable fungi below 1, suggesting minimal indoor sources of fungi. In contrast, 56% of the apartments had I/O ratios for culturable bacteria above 1, indicating the prominence of indoor sources of bacteria. Culturable fungi I/O ratios in apartments serviced by central heating, ventilation, and air-conditioning (HVAC) system were lower than those in apartments with window AC. The type of ventilation system did not have a significant effect on the presence of indoor culturable bacteria. A significant positive association was determined between indoor dew point (DP) levels and indoor culturable fungi (P<.001) and bacteria (P<.001), regardless of ventilation type. Also, residents in apartments with central HVAC did not experience extreme DP values. We conclude that building ventilation systems, seasonality, and indoor sources are major factors affecting indoor bioaerosol levels in residential buildings.

Nearly zero energy renovation concepts for apartment buildings

Revised EPBD directive has set ambitious targets for renovation. It is stated that Member States shall establish a long-term strategy facilitating the cost-effective transformation of existing buildings into nearly-zero energy buildings. The long-term strategy should set out a roadmap with a view to the long-term 2050 goal of reducing greenhouse gas emissions in the European Union. This creates the need for cost-efficient renovation solutions which can be implemented in large scale. The impact assessment shows that roughly a doubled renovation rate of 3 % would be needed to accomplish the energy efficiency ambitions in a cost-effective manner. The objective of this study is to specify renovation concepts with adequate heating and ventilation, based on Estonian and German apartment buildings and corresponding local solutions. Energy performance and sizing analyses were conducted for selected multifamily apartment buildings typical for 1960-70es with three different renovation concepts. Energy calculations were conducted with national energy calculation methods and national energy requirements for major renovation. In the renovation, the building envelope insulation, air tightness, and heating and ventilation systems were improved so that the renovated building complies with national nearly zero-energy requirement for major renovation.

Perceived daylight conditions in multi-family apartment blocks – Instrument validation and correlation with room geometry

This article investigates the relation between subjective evaluations and objective measurements of daylighting in multi-family residential buildings. More specifically, the suitability of an observer-based environmental assessment (OBEA) instrument to assess indoor daylight conditions was tested in a field study conducted in six typical multi-family apartment buildings in the central and metropolitan area of Malmö (Latitude: 55.6 °N), Sweden. The OBEA used self-administered questionnaires based on bipolar semantic scales aiming to capture two perceived daylight qualities: brightness and distribution. Following a factorial approach, one component pertaining to perceived brightness was deducted (“Brightness”, Cronbach's alpha = 0.89) and validated by associating it with outdoor global horizontal irradiance (Spearman's rS = 0.566, p = 0.006), which was monitored during the survey. Subsequently, this component was correlated with key geometric attributes of the investigated apartments to highlight the most important associations between perceived brightness and room geometry. Results indicate that the OBEA displays high internal reliability for the derived component, and is fit for daylight perception evaluations in residential spaces. In addition, the analysis showed a tendency for variables pertaining to window size to associate with perceived brightness, but also contributing to this association was the level of global horizontal irradiance.

Critical Performance Aspects of Retrofitting Apartment Buildings Using a Multifunctional Façade System

There is huge market potential for energy refurbishment solutions in European buildings. This paper analyzes the challenges related to using a multifunctional energy efficient façade system, the “Meefs” system, in retrofitting multi-family apartment buildings. Similar challenges often occur also in other comparable façade renovation solutions. The focus is on hygrothermal performance even as other aspects are also discussed. After introducing the hygrothermal performance challenges of the Meefs system, numerical case analyses are performed in three different climatic conditions. The results for 26 cases are presented. A core result is that the drying of any exterior renovation system is mandatory to guarantee safe operation in different European climate conditions. This emphasizes proper design needs in all climates. Based on the analyses, design recommendations can be given for the Meefs system. In Central and Northern European climates, the system contains challenges which may hinder implementation in practice.

Environmental Benefits of Timber-Concrete Prefabricated Construction System for Apartment Buildings – a Simplified Comparative LCA Study

The aim of a research project TiCo (Timber Concrete) is to create a standardized flexible construction system for multifamily apartment buildings for central European climatic conditions with low environmental impact. It exploits advantages of advanced prefabrication and favourable material properties of its main elements. Prefabricated structural system was designed using concrete frame with thin columns and lightweight ceilings with reinforcing core. Façades and interior partition walls were designed from prefabricated timber frame panels. The paper presents a simplified comparative LCA study of the designed TiCo building system and conventional building solutions. The compared variants had the same key parameters – load bearing capacity and heat transfer coefficients of building’s envelope. The analyses include load-bearing structures, façade, partition walls, foundations and roof. The others like HVAC systems, floors, doors, windows or tin work were not included. A simplified comparative LCA is based on procedure described in method SBToolCZ, which evaluates the quality of buildings in terms of sustainability. The assessment covered embodied environmental impacts of the construction system structures with their replacement based of their service lives. Prefabricated concrete frame structure with timber envelope was found environmentally friendlier compared to conventional solutions. The combination of the concrete load-bearing structure and lightweight timber frame panels that benefits from favourable characteristics of both materials for the given purpose appropriately used in the construction appeared to be an efficient way of minimizing building’s environmental impact.

Križno lamelirani les – lastnosti in zahteve

Cross-laminated timber (CLT or X-Lam) is a modern building material used for load-bearing construction purposes in residential and non-residential buildings. CLT production has been increasing rapidly in recent years. CLT is suitable for wall, floor, ceiling and roof elements in the construction of houses, multi-family apartment buildings, industrial and storage halls and other buildings and bridges. Manufacturers demonstrate compliance with the essential requirements of the European Construction Products Regulation (CPR) on the basis of an initial type testing and the findings of a factory production control examination. In 2015, a harmonized European standard for CLT was adopted, which defines the requirements for built-in materials, the production and demonstration of constancy of performance, and the CE marking. The article presents the production technology and basic characteristics of CLT and the content of standard EN 16351.

Towards Sustainable Renovation: Key Performance Indicators for Quality Monitoring

The aim of this study is to propose the rational quality monitoring of the renovation process with methodology for data collection and analysis. The presented approach is based on a complex system of criteria that enables the comprehensive evaluation of the quality of the renovation process. Methodology that is developed for the rational quality monitoring of the renovation process can be used for long term monitoring activities to ensure that the system is up to date, while reflecting the concerns of the key stakeholders and the transfer of requirements. The main emphasis lies on the identification of the rapidly changing environment (regulations, technologies, needs and expectations of building owners, etc.). Quality monitoring will also serve as an analytical framework to analyze the effects of renovation and to identify what measures shall be undertaken to ensure that the renovation delivers the most positive results. This paper presents the case study analysis of renovated multi-family apartment buildings, the existing indicators of the renovation monitoring scheme and the structure of the proposed monitoring system of the renovation processes, key indicators, the main components of the system, and their links.

Life cycle assessment of small-scale greywater reclamation systems combined with conventional centralized water systems for the City of Atlanta, Georgia

This study examines a hybrid system (HS) that combines a greywater reclamation system with the centralized water system. Greywater is collected from laundry, showers, faucets and dishwashing and is reclaimed for non-potable on-site purposes (i.e., irrigation and toilet flushing) by using submerged membrane bioreactors (MBRs). This technology can reduce the burden of the conventional system (CS), defined as the water supply and wastewater treatment systems within the City of Atlanta. We conducted a life cycle assessment (LCA) comparison of the HS and CS using TRACI v2.1, which simulates ten impacts related to the ecosystem, human health and natural resources. We simulated the technology feasibility for nine residential zones, including five single-family house zones (SFZs) and four multi-family apartment building zones (MFZs) that vary by land use and population density (0.4–62.2 persons per 1000 m2). The greywater reclamation system reduces non-potable water demand in SFZs (by 17–49%) and MFZs (by 6–32%) while simultaneously reducing electricity consumption by 17–49% and 32–41% for SFZs and MFZs, respectively. Moreover, the LCA score of the CS is 20–41% lower than that of the HS. However, the sensitivity analysis indicates that energy sources in electricity generation play a critical role in reducing and stabilizing life cycle impacts. The results indicate that the LCA scores stabilize at higher population densities. Therefore, once the greywater reclamation capacity is exhausted, municipalities can further decrease the life cycle impacts related to water infrastructure through improvements in the electricity generation infrastructure.