Common Residential Building Research Articles

Optimization of construction costs and energy consumption during the operation period of residential buildings (Case study: common residential buildings in Tehran)

Optimization of construction costs and energy consumption during the operation period of residential buildings (Case study: common residential buildings in Tehran)

Seismic Performance of Desert-sand Autoclaved Aerated Concrete Block Wall Constrained by Precast Integral Construction Column

Considering the structural types and construction techniques used in common residential buildings in Xinjiang, the paper proposes a novel masonry structure, i.e., desert-sand AAC blocks constrained by a precast integral construction column. In order to study the seismic performance of the structure, five wall specimens with different constraints are designed and fabricated and further compared and analyzed in terms of failure mode, hysteretic performance, energy dissipation capacity, ductility, stiffness degradation, and other performance indexes. It has been determined from the results that under horizontal low-cycle repeated loading, the main failure cracks of the desert-sand AAC block wall constrained by the precast integral construction column are intersecting oblique cracks, and the cracks in wall failure penetrate along concrete blocks. The stiffness degradation rate of the wall constrained by the water-resistant gypsum construction column gradually decreases with increasing vertical compressive stress. The wall constrained by the water-resistant gypsum construction column with arranged steel bars has a desirable ductility. Under the same vertical compressive stress, the wall constrained by the water-resistant gypsum precast construction column with arranged steel bars has a significant energy dissipation capacity from cracking to the ultimate state. (4) A restoring force model is built for desert-sand AAC block walls constrained by the precast integral construction column using a three-fold line model, offering technical support for the elastoplastic seismic analysis of structures.

Simulation-based consequence models of seismic direct loss and repair time for archetype reinforced concrete frames

Seismic risk management of building portfolios requires a reliable evaluation of earthquake-induced losses. This is commonly performed using consequence models linking structure-specific damage states (DSs) experienced by a building to a given loss metric (or decision variable). This study demonstrates a simulation-based procedure that derives refined probabilistic consequence models considering two essential loss metrics: direct-loss and repair-time ratios (repair cost or time normalised by the corresponding reconstruction values). Nine case-study reinforced concrete frames with various heights and design-code levels are developed to represent common residential buildings in Italy and the Mediterranean region. The proposed procedure starts by defining building-level, structure-specific DSs that reflect the increasing structural and nonstructural damage for the nine frames. Their seismic response is then assessed by analysing two-dimensional nonlinear numerical models and deriving building-level fragility relationships. Next, component-based direct-loss and repair-time analysis is conducted via the FEMA P-58 methodology, which computes such metrics at multiple ground-shaking intensities using Monte Carlo sampling. The consequence models are finally characterised by fitting probabilistic distributions to the direct-loss and repair-time realisations after conditioning them on the respective global DSs sustained by each case-study frame. This procedure enables deriving enhanced consequence models that can be easily implemented in risk analysis of building portfolios to obtain quick loss estimates. This study finally sheds some light on the possibility of correlating repair time to direct loss, which might be useful in estimating indirect losses resulting from downtime, particularly in cases where repair-time data or models are unavailable.

Sustainability of building-integrated bioclimatic design strategies depending on energy affordability

Bioclimatic design strategies have proven their efficiency in improving the sustainability of buildings. However, their economic benefits, regarded as the main incentive for building owners to incorporate such strategies into buildings, are still unclear since they depend on several factors including the countries' energy accessibility level. This study explores the role of energy affordability level and climatic conditions in incorporating bioclimatic design strategies. Therefore, the effectiveness of integrating seven bioclimatic approaches into a common residential building in six different locations worldwide with disparate climatic conditions, gross domestic products and electricity prices is assessed. The outcomes of each strategy are generated using EnergyPlus software and evaluated based on key energy, economic and environmental metrics. The findings reveal that, for most bioclimatic design strategies, the highest economic profits are achieved in regions where the electricity price to gross domestic product (EPGDP) ratio is high (i.e., where energy is unaffordable). Indeed, the shortest discounted payback period is obtained by using suitable glazing size in hot/moderate climates with higher EPGDP ratio (0.04/0.13 years) and thermal insulation in cold ones (1.17 years). Moreover, the greatest net present values are acquired by integrating thermal insulation in hot/cold zones with up to k$14.04/k$76.73, and window opening design in moderate climates (k$7.32). Additionally, the investigated strategies exhibit significant energy savings and carbon emissions mitigation. This study confirms the benefits of bioclimatic design; nevertheless, awareness campaigns and incentive programs are also essential in motivating households to integrate sustainable strategies into their buildings, especially in regions where energy is affordable.

A life cycle assessment method to support cities in their climate change mitigation strategies

National climate change mitigation objectives must be translated to the city level and to specific sectors, with locally-relevant policy measures. However, assessing the decarbonization value of these measures is a challenge for local policy makers and few local consumption assessment studies integrate a systemic vision. This research presents a multi-criteria city-scale Life Cycle Assessment method focusing on the three largest carbon-emitting sectors in cities: food, residential buildings and daily mobility, with an original combination of databases and models. For food, databases were used to evaluate environmental impacts based on socio-demographic characteristics. For building and mobility, modeling tools were used and adapted at different scales: with local spatial refinement for mobility and the creation of archetypes representing the city's most common residential buildings. A demonstration of this new cross-sectoral method was conducted on Montreuil city in the Parisian region, to (1) evaluate the current greenhouse gas emissions (GHG), and (2) test the possible reductions following different measures. The developed assessment framework provides various interpretation, with disaggregated contribution, mapping, and scenario analysis. For instance, the application of ambitious measures and important lifestyle changes reduced GHG in these sectors by 30%, far from the French government's ambitions of a 55% reduction by 2030.

Cleaner construction of durable green rooftop in residential buildings with municipal water supply

Rooftop vegetation is a popular choice among architects and builders at present because of its aesthetical appeal and environmental benefits. It has consistently been regarded as a sustainable and eco-friendly approach to the construction of buildings. Recently, people have adopted rooftop vegetation in their homes, and it has become popular. Large scale roof gardens in commercial buildings are safe due to proper design and protection techniques by experts. Due to economic constraints, rooftop vegetation in normal residential buildings cannot follow stringent regulations and expensive protection techniques. However, it is to be kept in mind that any rooftop vegetation endeavour, if not properly designed and maintained, might result in severe durability problems in roof concrete. There are unseen drawbacks to simple practices of concrete rooftop vegetation in common residential buildings, specifically the presence of aggressive agents in treated water from the public water supply, which is commonly used to irrigate the vegetation in such buildings. The effect of vegetation on the concrete roof and its influence on various salient aspects, specifically the durability of concrete, is discussed in this paper. The influence of chlorides and sulphates present in the municipal treated water used for watering plants and shrubs on the durability of concrete is also presented. Moreover, the chloride threshold value of the reinforcement is between 0.1% and 1.5%. The total charges passed through concrete are also reduced to less than 1000 Columbus with the addition of agricultural by-products. In addition, root intrusion tendency of commonly grown plants on rooftop and corrosion due to agricultural chemicals are also mentioned. In the latter sections, remedial measures are highlighted to minimize the negative impacts of rooftop vegetation on the durability of concrete. In addition, to highlight the impact of chlorides on the roof concrete, the study also presented the chloride permeability and service life of blended concrete.

Exergy Analysis of the Prevailing Residential Heating System and Derivation of Future CO2-Reduction Potential

The residential heating sector accounts for a large share of the worldwide annual primary energy consumption. In order to reduce CO2-emissions, it is therefore particularly important to analyse this sector for potential efficiency improvements. In Europe, natural gas boilers are the most widely used heating technology since they are cost-effective and can be installed in any type of building. The energy efficiency of these boilers is already high. However, in their internal process, heat is generated at a high temperature level which is only used for space heating and therefore a high amount of exergy remains unused. This research aims to develop the potential of using the exergy to further improve the efficiency of the systems. A novel combination of methods is applied to analyse the thermodynamic behaviour of gas-fired boilers in detail and over the cycle of a year. The analysis is performed in two steps: In the first step a system is examined in stationary operating points. This is carried out through an experimental setup and a three-dimensional numerical simulation. In the second step, the obtained data is applied to a transient annual building simulation. The results show the temporal distribution and total amount of the annual exergy loss for a common residential building. The exergy loss accumulates to 16,271 kWh per year, which shows the high potential to partially convert the exergy to electrical energy and significantly reduce the external electricity demand and CO2-emissions of the building. Based on this, new technologies such as Thermoelectric Generators can be developed, which can enable this potential.

Battery Size Optimization With Customer PV Installations and Domestic Load Profile

Photovoltaic (PV) is a highly feasible solution for modern renewable energy-powered residential buildings in terms of deployment and cost reduction of utility bills. The installation of solar PV systems along with optimal battery energy storage systems (BESS) size is the most popular energy cost minimization solution and will continue to increase rapidly in the coming years considering the European Union (EU) framework for nearly zero energy buildings (nZEBs). The current methods lack BESS size optimization and a comprehensive solution to charge/discharge BESS from PV and the grid. The main goal is to be self-sufficient and sustainable while having minimal dependence on the electrical grid. Therefore, this paper presents an efficient energy management model and optimal size of the BESS as two key factors to effectively minimize the total energy consumption cost of the nZEBs while having a minimum dependence on the grid. The energy management system is developed using linear programming and solved using simplex and interior-point methods. In addition, a heuristic algorithm is presented to determine the optimized charging and discharging schedule for nZEBs. A detailed techno-economic analysis of the proposed system is conducted for the whole year (covering all four seasons summer, winter, spring, and autumn) considering three common residential building cases and three different electricity pricing methods. We determined that seasonal electricity pricing is the favorable and economical option to schedule charging and discharging of BESS from the grid in several terms such as, minimum total hours of grid usage, the maximum number of charging hours of BESS from the solar PV system, maximum BESS discharging hours to sell energy, the minimum number of BESS charging hours from the grid, maximum number of discharging hours for energy usage within nZEBs, maximum revenue earned, and peak electrical load reduction for the grid.

Innovative energy efficient thermal insulation to ensure indoor comfort in nZEB buildings

The paper presents the analysis of water and heat transfer through walls being thermally insulated with vegetal materials. The analysis identifies the risk for condense accumulation in the outer layers of external walls of a common residential building located in the coldest climatic regions of Romania. Different wall structures and insulation thicknesses are systematically considered with statistical extreme temperature and humidity outdoor values. Results are useful in designing nZEB individual houses with green and sustainable technologies that also provide energy savings and indoor conditions for good comfort and health in these desired building concept.

EVALUATIVE PERCEPTION CRITERIA FOR URBAN ENVIRONMENT OBJECTS WITH RESIDENTIAL BUILDINGS OF VLADIVOSTOK AS AN EXAMPLE

Aim: To analyze the evaluative perception criteria for urban objects, in particular, residential buildings. Methods: The sample consisted of 100 residents of Vladivostok, divided into three groups: «students», «adults» and «seniors». Photos of the most common residential buildings in Vladivostok city were used as stimuli. Respondents were asked to rank them according to the degree of preference. Then the data were processed using a multidimensional scaling of individual preferences. Results. Two evaluative perception criteria suitable to the entire sample were identified: first - perceived comfort/novelty and the second - buildings originality and individuality. Intergroup differences were found according to the criterion «comfort/novelty»: students were more inclined to the comfort/novelty pole than the other groups, and they preferred new high-rise buildings located at this pole to a greater extent. This allowed us to assume that they had a special semantic content of images of such objects. According to the criterion of «individuality», the preferences of all groups of respondents consistently tend to houses perceived as non-trivial (these were new high-rise and historical buildings). At the same time, most buildings were perceived, on the contrary, as ordinary, devoid of originality, which reveals a mismatch between the preferred and the actual. The identified criteria are interpreted as two points of view in the perception of urban environment objects. The first one is associated with the tendency of mental projection inside the object, the second emphasizes the visual, external qualities of objects. Conclusion: Application of the photo ranking technique with subsequent multidimensional scaling method allowed us to identify the evaluative perception criteria for residential buildings. The results obtained can have value in the context of improving urban environment.

Energetic, exergetic and exergoeconomic assessment of transcritical CO2 reversible system combined with dedicated mechanical subcooling (DMS) for residential heating and cooling

A transcritical CO2 reversible heat pump-air conditioning system combined with dedicated mechanical subcooling (DMS) is proposed as an annual heating and cooling solution. A common residential building is selected as a scenario to assess the system annual performance from the viewpoint of energetic, exergetic, and exergoeconomic, and compare with traditional CO2 system (BASE). The influences of terminal type, climate condition, and energy-saving potential are discussed. The results indicate the annual performance factor (APF) of CO2 system is significantly improved by up to 6.23 ~ 22.90%. APF generally increases with the latitude, and it achieves the highest value of 3.41 by using small temperature difference fan-coil unit (STD-FCU) as terminal. The annual exergy efficiency (AEE) is promoted by 7.25 ~ 24.79%, and the throttling irreversibility can be significantly reduced by adopting DMS. From the perspective of thermoeconomic, introducing DMS to CO2 system is cost effective. The total cost, including non-exergy-related investment and cost of exergy destruction, is reduced by 16.96% for heating and 4.52% for cooling. The annual exergoeconomic factor increases with the improvement of building energy-saving potential while decreases with the compressor price reduction. To widen the application of CO2 system, it is suggested that the price of CO2 compressor should be reduced, such as with the help of government subsidies. Furthermore, the thermal insulation performance of the residential building should also be improved, especially for the severe cold and cold regions.

Dynamic optimization of multi-retrofit building envelope for enhanced energy performance with a case study in hot Indian climate

When multiple thermal retrofits are to be installed in a building envelope for improving its energy performance, several questions arise such as “what should be the thickness of retrofits and where they should be placed within the wall/roof”, “which retrofit should be installed towards the exterior and which one should be installed towards the interior of the envelope”. Such judgements are made in contemporary studies by comparing limited predefined configurations where either the thickness or the location of retrofit assumes only a few discrete values within the envelope. The novel approach proposed in this study utilizes spatial discretization of structural layers in a composite envelope for two fold benefit. A new version of Genetic Algorithm (GA) is developed for this purpose by modifying its key operational stages. The GA is implemented in a practical scenario to optimally configure a multi-retrofit envelope (carrying phase change material and thermal insulator) of a common residential building in hot climate of India. Analysis of a single housing unit demonstrates that up to 33.5% of heat gain reduction and 9.2 kWh/day of electricity saving are achievable with improved envelope design.

A science-based approach to setting climate targets for buildings: The case of a New Zealand detached house

Climate change mitigation requires the construction of low-carbon buildings. The use of Life Cycle Assessment provides useful information to support eco-efficiency improvements and therefore, to reduce the climate impact of buildings. However, it does not ascertain whether a proposed design aligns with achieving the global climate target of limiting global warming to below 1.5 °C or 2 °C. This study, therefore, introduces a science-based approach for setting climate targets for individual buildings using a whole-of-life cycle perspective. It involves assigning a share of the 2 °C global carbon budget for 2018-2050 to a country, its construction sector, and finally to each life cycle stage of a building. A stock projection model is used to account for the projected growth in the number of buildings and associated climate impact in a country up to 2050. The approach was applied to define a climate target for a New Zealand new-built detached house of 198 m2 gross floor area, the most common residential building type in the country. The weighted average climate impact of three New Zealand new-built detached houses was compared with the defined climate target. The results showed that the climate impact of new-built detached housing exceeded the climate target by a factor of five. When the climate impact was compared with the climate targets at each life cycle stage, exceedances were a factor three to five higher across the different life cycle stages. The proposed approach has potential to guide designers and other interested stakeholders to operate the construction sector within planetary boundaries.

A top-down approach for setting climate targets for buildings: the case of a New Zealand detached house

Climate change mitigation requires the construction of low/zero-carbon buildings, and this is a challenge for designers. The use of Life Cycle Assessment (LCA) provides useful information to support eco-efficiency improvements and therefore, to reduce the climate impacts of building designs. However, it does not provide information about whether a proposed design aligns with achieving the global climate target of limiting global warming to below 1.5°C or 2°C. This study, therefore, introduces an LCA-based top-down approach for setting climate targets for the whole life cycle of buildings in terms of greenhouse gas emissions. It involves assigning a share of the 2°C global carbon budget for 2018-2050 to a country, to the construction sector of the country, and finally to a building. The approach includes a stock model that accounts for the projected growth in the number of buildings and associated climate impacts in a country up to 2050. The proposed approach was applied to a detached house in New Zealand, the most common residential building type in the country; it was found that the climate target of a New Zealand detached house over a 90-year lifetime is 71 tCO2eq. This modelling approach has potential to guide designers and other interested stakeholders in development of building designs enabling the building sector to operate within a selected global climate target (such as the 1.5°C or 2°C target).

Improving the Sustainability of Traditional Dwellings in Yunnan, China: Seismic Resistance Testing of Wood-frame and Earth-Built Wall Dwellings

The Southwest provinces of China are locations with a rich variety of different dwelling design typologies based on traditional cultures and ethnic groups. In this area, the Province of Yunnan has many such dwelling types, and it is also an area with most frequent earthquakes in China. The seismic problems of housing structure must therefore be solved as part of the study on sustainable development of villages to provide relevant advice for future design options. This paper reports research, which evolved over a ten-year period that deals with the seismic capacity of residential buildings. Simulations using shaking table tests were carried out to assess the performance of traditional residential structures as well with the impacts of material modifications and the structural strengthening of common residential building components found in Yunnan. Relevant and pertinent construction technology solutions that could enhance the seismic capacity of residential buildings and act as innovative improvements for the sustainability of rural dwellings are suggested.

Effects of Vernacular Climatic Strategies (VCS) on Energy Consumption in Common Residential Buildings in Southern Iran: The Case Study of Bushehr City

This study aims to use the vernacular climatic strategies (VCS) of traditional dwellings in Bushehr, in the common residential buildings of this southern Iranian city (which is characterized by its hot and humid climate), and provide answers to the following question: What effects do VCS have in terms of energy consumption in these buildings? This study has been conducted at three levels. At the first level, three context-based climatic solutions including shading, natural ventilation, and insulation of external walls and roofs were identified and selected based on bibliographic study. At the second level, a case study reflecting the current typology of common residential buildings in Bushehr city was selected. A combination of the mentioned climatic solutions was used in the baseline case to create a developed model. Based on the space layout of the developed model and some design criteria, a series of proposed models was also created and modeled. The selected case study building was also used to establish a local weather station at a height of 12 m based on the roof, collecting local climate data which were then used for simulation to improve simulation accuracy. Finally, all models were simulated with the use of Design Builder software under natural ventilation conditions during moderate climatic periods of the year while split air-conditioning systems were used during hot and humid periods. The results showed reductions of 16% in energy consumption and 22% in CO2 emissions for the developed model, and reductions of 24–26% in energy consumption and 32–34% in CO2 emissions for the proposed models, as compared with the baseline model. Furthermore, all proposed models achieved lower annual energy consumption when compared with a selection of international sustainable low energy standards and domestic energy performance references for the Middle East region. Further studies are also recommended, and there is potential for combining VCS with other solutions such as on-site renewable energies.

Assessing the relationship between urban planning options and carbon emissions at the use stage of new urbanized areas: A case study in a warm climate location

The trend in urban population growth marks the sustainable development of cities as a critical challenge on the path towards the efficient use of resources and the mitigation of the environmental impact of human activity. Scientific studies have generally focused on the quantification of the environmental impact derived from the usage/operational stage of buildings. This study also includes the impact associated with the use of public facilities and services in cities.The aim of this paper is to study the CO2 emissions from the use stage of buildings and public facilities through different urban planning solutions. Six development scenarios have been evaluated, considering the most common residential building typologies with a common construction surface, which includes: single- family units (detached and semi-detached) and apartment blocks of different building heights. The main finding is the relevant contribution of the use of urban facilities and public services to the overall environmental impact of an urbanized area during its lifespan. The impact of urban planning on the total carbon emissions in cities is shown in the results.The outcome of this research will guide relevant stakeholders in urban development to promote sustainability criteria in urban design guidelines and their inclusion in the policy arena. The results will also help city managers to better understand the role of public services in the overall environmental impact of urbanized areas.

The relationship of vibration and groundborne/structureborne noise in buildings relative to vibration in the ground from exterior sources

Ground vibration generated by roadway traffic, rail, and transit systems can be transmitted into buildings were it can either be perceived as feelable vibration or as sound radiated from the interior building surfaces, i.e., floors, walls, and ceilings. The amount of vibration that is transmitted into a building is affected by a reduction as the vibration is transmitted from the ground to the foundation of the building (i.e., coupling loss) and amplification due to resonances within the building structure. This paper will discuss these effects and measurements that have been conducted to quantify the effects for common residential building construction adjacent to rail lines. A brief discussion regarding the relationship of groundborne/structureborne noise to interior vibration from exterior sources of ground vibration will be included.

Numerical Study on the Effect of Natural Ventilation and Optimal Orientation of Residential Buildings in Changsha, China

Indoor environment affects human's health directly. In residential buildings, natural ventilation can be applied as an effective way of ventilation. Different window-opening behavior results in different indoor environment. Five window-opening behavior of a common residential building in Changsha were compared and analyzed by using Airpak. Energy consumption of building with different orientation was calculated by DesignBuilder according to the Changsha typical meteorological data. A new evaluation index was proposed to compare the design schemes with consideration of the performance of natural ventilation and the building energy consumption. The optimal scheme combination of the building orientation and the opening's position was obtained by the index.

Development of an evaluation strategy of hydronic balancing valves for radiant floor heating systems

In order to increase thermal comfort and energy efficiency, individual room control is highly recommended for radiant floor heating systems. For this reason, hydronic balancing is essential to provide the design flow rate to each branch circuit, which can be regarded as the ultimate goal of individual room control for radiant floor heating systems. In general, balancing valves are widely applied to hydronic circuits of radiant floor heating systems in common residential buildings, in order to achieve the purpose of hydronic balancing. This study aims to suggest an evaluation strategy of balancing valve performance for radiant floor heating systems. In the strategy, adjustment range and accuracy are evaluated by using the Kv value, in order to evaluate the balancing performance for practical applications of balancing valves. Additionally, the flow distribution by balancing valves was evaluated with the hydronic network simulation, by which flow quotients of hydronic circuits were investigated. Based on the evaluation strategy, the performances of six different balancing valves, which are applied to typical residential buildings, were successfully evaluated. Practical application: This study presents an evaluation strategy to evaluate the performance of hydronic balancing valves for radiant floor heating systems. The proposed evaluation strategy will be able to provide a method to analyse the impact of hydronic balancing and to determine suitable balancing valves for radiant floor heating systems in residential buildings. Therefore, it is expected that the results will be helpful to researchers for indoor environment, building service engineers, system designers, and those who want to analyse the hydronic control of radiant floor heating systems.