Search Results (17)

The increasing rate of population growth and urban expansion has led to a higher demand for fossil fuels, which, in turn, directly generate greenhouse gas emissions into the atmosphere. These emissions contribute to environmental problems such as global warming and climate change. This study aims to present the total life-cycle energy analysis (LCEA) of a single-family detached house designed with an energy conservation approach. Using a cradle-to-grave scope, this study quantifies the embodied energy in six stages of the building’s life cycle, i.e., initial, transportation, construction, operational, recurrent, and demolition. An input–output (IO)-based method was employed to construct a Thailand-specific embodied energy coefficient for 36 key building materials. This coefficient was then used to quantify both the initial embodied energy and the recurrent embodied energy in this study. The case-study house was broken down into 13 building materials. Concrete was the most consumed material, followed by fiber–cement, steel, and timber, in that order. However, the results of the embodied energy distribution for these materials revealed that fiber–cement ranked first, accounting for 29%. Steel was next, at 21%, followed by concrete at 18%, and, finally, aluminum at 12%. The case-study house had an initial embodied energy of 7.99 GJ/m² and a total life-cycle energy consumption of 0.66 GJ/m²/year. This study provides valuable information on LCEA for residential buildings, fostering public understanding of energy conservation in the Thai context. Furthermore, this study’s results can be applied to establish energy conservation guidelines for residential buildings. These guidelines can help reduce energy resource depletion, carbon emissions, and environmental problems, ultimately contributing to Thailand’s goal of achieving carbon neutrality by 2050. Full article

The integration of the Internet of Things (IoT) and Building Information Modeling (BIM) is progressing. The use of microcontrollers and sensors in buildings is described as a level 3B maturity in the use of BIM. Design companies, contractors and building operators can use IoT solutions to monitor, analyze or manage processes. As a rule, solutions based on original Arduino boards are quite an expensive investment. The aim of this research was to find a low-cost IoT solution for monitoring, analysis and management, and integrate it with a BIM model. In the present study, an inexpensive NodeMCU microcontroller and a temperature and pressure sensor were used to study the thermal comfort of users in a single-family home. During the summer season, analysis of the monitored temperature can contribute to installation (HVAC) or retrofit work (for energy efficiency). The article presents a low-cost solution for studying the thermal comfort of users using a digital twin built-in BIM. Data obtained from sensors can support both the design and management processes. The main contribution of the article enables the design, construction and use of low-cost circuits (15.57 USD) even in small developments (single-family houses, semi-detached houses, terraced houses, atrium buildings). Combining IoT sensor telemetry with BIM (maturity level 3C) is a challenge that organizations will face in the near future. Full article

Studies of the effects of removing underfloor insulation and increasing the thermal capacity of building walls are currently found almost exclusively in existing vernacular architecture and rammed-earth buildings, mostly in countries with warm climates. This paper proposes the combined use of these two measures to reduce the risk of overheating in a detached single-family house in a temperate climate during the summer. Experimental studies conducted during the largest heat wave on record in the summer of 2019 showed that peak daytime temperatures decreased by 5.2 °C to 7.1 °C, and peak nighttime temperatures decreased by 4.7 °C to 6.8 °C. Simulation studies taking into account occupant heat showed that the proposed passive methods could, under the IPCC 8.5 scenario, eliminate the need for mechanical cooling in a detached single-family house in the temperate climate of Central and Eastern Europe by 2100. The actual heating energy consumption for the building with an uninsulated floor and increased wall heat capacity was 5.5 kWh/m² higher than for the reference building, indicating that it can be a near-zero energy building. The proposed concept is in line with the new approach to the energy design of buildings, which should not be limited to reducing thermal energy demand, but should also respond to the needs arising from global warming. Full article

In this work, data from ten (10) meteorological stations in various areas of Thessaloniki, Greece were used in order the cooling and heating degree days for each station to be calculated. The specific data were applied to a detached house for each of the ten areas considered. Furthermore, an analysis of the thermal insulation adequacy of the single family house that has been selected with the necessary methodology and the necessary sketches was conducted in order to have the illustration of the building. The study was divided into two cases, where the first refers to a typical thermal insulation that characterizes a building of the territory of Greece, and the second case where the residence has undergone a radical renovation of its thermal insulation. Results show that three different climatic zones appear in the same region instead of one. Full article

High heating expenses are observed in numerous Chinese rural houses located in severe cold regions due to the high heating demand, inferior envelope performance and low-efficiency heating equipment. The local traditional heating methods include Chinese Kangs and coal boilers with water-based radiators. The intermittent operation and manual regulation of these systems result in significant temperature differences and inadequate thermal comfort. This study presents the cost-optimal envelope renovation solutions with the minimized lifecycle cost (LCC) during a 20-year discount period and CO₂ emissions of annual delivered energy consumptions. A single-family detached rural house in Harbin was used as a case building, illustrating the typical state of comparable houses in this climate context. Simulation-based multi-optimization analysis was conducted in this study using the building simulation tool IDA ICE and its integrated optimization tool AutoMOO. The results indicate that the cost-optimal renovation solutions with intermittent and continuous heating can cut CO₂ emissions by 30% and 40%, respectively. The LCC with intermittent heating is still 7% greater than its pre-renovation case, which may require external financial support to encourage the renovation conduction, while the LCC with continuous heating decreased by 8% after renovation. According to the comparison results, cost-optimal solutions have significant advantages in both reductions of LCC and CO₂ emissions over standard-based solutions. Moreover, utilizing intermittent heating is more effective than continuous heating in demonstrating the positive impacts of envelope renovation on increasing average temperature, decreasing temperature differences and lowering occupied time at low thermal comfort levels. Full article

Air leakage is an essential factor contributing to overall building performance. It plays a major role in determining energy consumption in harsh climates, particularly in residential buildings, as it represents a significant component of the envelope-induced thermal load. In centrally air-conditioned houses, the HVAC system can substantially alter the pressure distribution across the exterior envelope, reforming the air leakage behavior. Nonetheless, limited information is available to characterize and better understand such behavior to accurately predict building performance and energy consumption toward meeting the emerging requirements for sustainable buildings. This study experimentally investigated the air leakage behavior of a selected sample of centrally air-conditioned typical single-family detached houses in Saudi Arabia. The air leakage behavior was investigated by measuring the overall airtightness and the contribution of the different air leakage paths using the viable method of the blower door test (BDT). The air leakage rate was then calculated using the measured induced pressure across the envelope during the HVAC system operation. Results indicated that the air leakage behavior is significantly altered by the pressurization induced by the central HVAC system, eliminating air infiltration and producing an outward airflow across the entire envelope. The study addresses a current challenge in characterizing envelope air leakage behavior for a common type of house and, thus, would indirectly contribute to more accurate thermal and energy performance assessments. Several aspects were highlighted for consideration when defining the contribution of air leakage to energy consumption prediction and studying air leakage behavior in other types of buildings. Full article

This article describes the innovative photovoltaic powered seasonal thermal storage—PVPSTS system. It was used in the design of a plus-energy detached single-family house with a usable area of 98 m². This area meets the requirements of the latest building regulations in Poland. The building, with the innovative HVAC installation, was subjected to energy analysis, and a numerical model was also developed. The model was tested based on TMY data for the location of Wroclaw, Poland. Analysis of the results allowed the authors to learn the specifics of the operation of the system throughout the year and to also define its efficiency. The required size of the storage stack was determined to be 1.6 × 1.6 × 0.3 m. The photovoltaic installation, which was integrated with the roof, can produce 48 GJ of electricity per year. This is five to six times more than the building’s heating needs, and any excess energy can be exported to the power grid. Full article

This article provides a comprehensive understanding of small house practices, including the perspective of Finnish architectural experts, by conducting semi-structured in-depth interviews and proposing an individually designed house case study with a particular focus on cost and quality. Key findings based on main themes including the role and qualifications of the architect, architect’s involvement, architect’s fee, reasons to hire an architect, implementation, quality, and cost, highlighted that: (1) architect can assist small house projects in many ways, such as accurately identifying the client’s needs, choosing the most suitable layout, and applications for building permits; (2) allocating sufficient time for planning an average of six months is critical for the thoughts of both the architect and the client to mature in peace; (3) the share of architectural design in the total cost of the project is around 3–5%; (4) it is estimated that the total amount of small houses designed by an architect is between 10–20%; (5) an architect’s typical client is reported to be those who dream of a long-term home and are concerned with aesthetics as well as functional quality; (6) the client is always satisfied with the quality of the house designed by the architect; (7) while an individually designed home may seem more costly than a prefab home, an architect-designed home can be affordable as long as the budget is known from the start of the project. It is believed that this paper will encourage the participation of architects in small house projects that will be expanded and established in the Finnish residential construction industry. Full article

According to the 2021 Global Status Report for Buildings and Construction published by the United Nations Environment Programme, global carbon emissions from the building sector in 2019 were nearly 14 gigatons (Gt), representing 38% of total global carbon emissions, including 10% from building construction. In the United States, the largest knowledge gap regarding embodied carbon in buildings exists at the whole-building level. The first step in creating informative policy to reduce embodied carbon emissions is to map the existing building stock emissions and changes over time to understand the primary contributing building types and hot spots (states), and then to compare and analyze mitigation scenarios. To fill this knowledge gap, this study first developed a bottom-up model to assess the embodied carbon of the US residential building stock by using 64 archetypes to represent the building stock. Then, the embodied carbon characteristics of the current building stock were analyzed, revealing that the primary contributor was single-family detached (SD) houses. The results indicated that the exterior wall was a major contributor, and that small multifamily housing was the most embodied carbon-intense building type. Two scenarios, the baseline scenario and progressive scenario, were formed to evaluate the effectiveness of six mitigation strategies. The progressive scenario with all mitigation strategies (M1–M6) applied produced a total reduction of 33.13 Gt CO_2eq (42%) in the cumulative residential building stock related to carbon emissions during 2022–2050, and a total reduction of 88.34 Gt CO_2eq (80%) during 2022–2100. The results show that with an embodied carbon emissions reduction in the progressive scenario (42% by 2100), the total embodied carbon emissions comply with the carbon budget of a 2 °C pathway, but will exceed the budget for a 1.5 °C pathway. Full article

Single-family detached homes—the lowest-density housing type—continue to dominate the U.S. home construction industry. These homes are carbon-intensive and automobile dependent; the built environments they produce militate against civic relations and attitudes. Cities need to increase density, support multimodality, and develop social capital, but these issues are not propelling cities to diversify their housing stock. The objective of this research is to facilitate this shift by establishing economic arguments for increased density and housing diversity. Municipal-level U.S. Census data is used to explore the interurban relationships between diversity in housing stocks and unemployment rates in 146 mid-size American cities. A measure of diversity, Shannon’s H, is applied to housing stock and found to be strongly associated with lower unemployment for workers over 25 years old after controlling for measures of urban social burden. In contrast to the much-heralded “trade-offs” between environmental quality, social equity, and economic development, these findings suggest that the dense, walkable, low-carbon city, and the economically sustainable city might be the same place. Full article

Valuation of single-family detached houses is necessary when determining the amounts of some taxes. The current systems of the Czech Republic are outdated in this respect, and they are based on procedures used in the 1980s. The values found do not correspond to current market conditions very often. This article attempts to verify the applicability of a methodology where the value of a detached house is decomposed into the value of the land and the value of the object as such when considering wear. For verification, 122 sales of detached houses in Ostrava and its surroundings were analyzed, and the results show that the values determined by the verified methodology do not differ by more than 10% from the actual sales prices in most cases. The methodology is very simple and practically applicable for users without deep knowledge of construction or valuation principles. It can be applied, for example, when calculating the bases of certain taxes or as an indicative guide for the pricing of real estate for sellers, buyers, real estate agents, etc. Full article

This study examines how the energy renovation of old detached houses affects the hourly power consumption of heating and electricity in Finland. As electrification of heating through heat pumps becomes more common, the effects on the grid need to be quantified. Increased fluctuation and peak power demand could increase the need for fossil-based peaking power plants or call for new investments to the distribution infrastructure. The novelty in this study is the focus on hourly power demand instead of just annual energy consumption. Identifying the influence of building energy retrofits on the instantaneous power demand can help guide policy and investments into building retrofits and related technology. The work was done through dynamic building simulation and utilized building configurations obtained through multi-objective optimization. Deep energy retrofits decreased both the total and peak heating power consumption. However, the use of air-source heat pumps increased the peak power demand of electricity in district heated and wood heated buildings by as much as 100%. On the other hand, peak power demand in buildings with direct electric heating was reduced by 30 to 40%. On the building stock level, the demand reduction in buildings with direct electric heating could compensate for the increase in the share of buildings with ground-source heat pumps, so that the national peak electricity demand would not increase. This prevents the increase of demand for high emission peaking power plants as heat pump penetration rises. However, a use is needed for the excess solar electricity generated by the optimally retrofitted buildings, because much of the solar electricity cannot be utilized in the single-family houses during summer. Full article

The Directive 2010/31/EU on the energy performance of buildings has introduced the standard of “nearly zero-energy buildings” (NZEBs). European requirements place the obligation to reduce energy consumption on all European Union Member States, particularly in sectors with significant energy consumption indicators. Construction is one such sector, as it is responsible for around 40% of overall energy consumption. Apart from a building’s mass and its material and installation solutions, its energy consumption is also affected by its placement relative to other buildings. A proper urban layout can also lead to a reduction in project development and occupancy costs. The goal of this article is to present a method of optimising single-family house complexes that takes elements such as direct construction costs, construction site organisation, urban layout and occupancy costs into consideration in the context of sustainability. Its authors have analysed different proposals of the placement of 40 NZEBs relative to each other and have carried out a multi-criteria analysis of the complex, determining optimal solutions that are compliant with the precepts of sustainability. The results indicated that the layout composed of semi-detached houses scored the highest among the proposed layouts under the parameter weights set by the developer. This layout also scored the highest when parameter weights were uniformly distributed during a test simulation. Full article

Few studies assess dog ownership and walking with both self-reported or perceived and audited or objective walkability and physical activity measures. Across two years, we examined both types of walkability and activity measures for residents living within 2km of a “complete street”—one renovated with light rails, bike lanes, and sidewalks. Audited walkability (Irvine–Minnesota Inventory) was more consistently related to dog ownership and walking groups than perceived walkability (Neighborhood Environment Walkability Scale—Abbreviated). Self-reported leisure walking was much higher (289–383 min per week) among dog walkers than among other groups (100–270 min per week), despite no difference in accelerometer-measured light or moderate-to-vigorous physical activity (MVPA). Furthermore, the most powerful difference between groups involved single-family detached home residence, which was much lower among non-dog-owners (44%) than among non-dog-walkers or dog walkers (81% and 70%, respectively). Given discrepancies across walkability and activity measures, we recommend future use of walkability audits and objectively measured physical activity over the current emphasis on self-report measures. We also urge greater attention to increased densities of housing, which may negatively affect dog ownership levels unless compensating supports for dog ownership and walking are created by public health messaging, dog-friendly policies, and dog-friendly housing and community design. Full article

Ulaanbaatar (Mongolia) is the coldest capital city in the world with approximately 98% of its heating demand satisfied by means of coal-burning stoves. This leads to enormous air pollutant emissions, with Ulaanbaatar being one of the top five most polluted cities in the world. In this study, an innovative solar hybrid heating system for the Mongolian scenario was used, which was based on the operation of a solar field composed of four series-connected evacuated tube heat pipe collectors, coupled with a thermal energy storage. The solar hybrid heating system was simulated and analyzed using the software TRNSYS. The simulations were designed to satisfy the heating demand of a typical single-family detached house located in Ulaanbaatar and were carried out with and without considering the soiling effects on the solar system operation. The overall performance of the proposed plant was compared with those associated with different fossil fuel-based Mongolian conventional heating systems, in order to assess the potential energy, environmental and economic benefits. The results highlighted that the proposed plant allowed for the obtainment of significant reductions in terms of primary energy consumption (up to 34.6%), global CO₂ equivalent emissions (up to 52.3%), and operating costs (up to 49.6%), even if the expected return on the investment could be unacceptable. Full article