Journal of Architectural Engineering

With advancement in sensor, control, and communication technologies, homes can now be equipped with more intelligent lighting, HVAC, entertainment, and safety/security systems, as well as appliances with many advanced features, including high energy efficiency. In particular, with computers becoming an integrated part of homes and smart phones offering remote communication with home systems, we are entering a new era in the home industry, an era of smart homes. This paper presents a categorization of smart homes based on their area of focus, such as energy, information and communication, security, health, environmental, home entertainment, and domestic appliances. However, the main objective of this paper is to review different types of energy smart homes in more detail under three major groups, including homes with energy-monitoring systems, systems with control capabilities, and systems with advanced data-processing capabilities. Smart homes with energy-monitoring systems merely provide the total or granular energy-consumption data of the house by using equipment such as in-home displays, whereas systems with control capabilities also include a control unit that can send proper signals for either passive or active measures, such as appliance on/off commands. In contrast, systems with advanced data-processing capabilities include an advanced central processing unit that can provide more complicated analysis results, such as systems that are equipped with an optimization algorithm to optimize the temperature or appliance schedules based on the residents’ comfort level and energy cost. Communication networks in smart homes and associated challenges for their design are also discussed in this paper.

In the present paper, the thermohygrometric performances of a clay brick wall, with reference to the typical northern Italy’s historical building envelopes, improved with an insulating layer on the inner side, are analyzed. Five alternative insulation materials have been compared: calcium silicate hydrates, fiberwood, expanded polystyrene, stone wool, and aerogel. The dynamic calculation tool WUFI (Wärme Und Feuchte Instationär) was adopted for simulating the realistic transient hygrothermal behavior of the multilayer building components exposed to natural local weather. Based on the climatic data of Turin and Tarvisio, chosen as representatives of the northern Italy urban centers and mountain localities, respectively, rain and solar radiation effects, water content distribution through the multilayered wall, mold formation in critical areas of the wall, and heat and vapor flows through the wall surfaces have been evaluated. Finally, the vapor barriers installation affecting the amount of condensate have been considered and compared with the prediction of the simplified steady-state Glaser method commonly adopted in the professional practice of building design. The results of the study indicate that a deep knowledge of the thermohygrometric performance of the wall assembly, together with a reliable/realistic condensation risk analysis, are key factors for a proper internal wall insulation, with particular reference to the actual need of the vapor barrier.

Building façades play an important role in building aesthetics and in protecting the structural system and contents from deterioration due to exposure to an aggressive environment. Well-designed façades can also help improve the durability and energy efficiency of the building as well as elevating the level of human comfort. In general, façade design and detailing have not received the same level of rigor and overall scrutiny as the load-bearing components of buildings. Current codes and standards require safety provisions for environmental separating elements of a building. However, there is an urgent need for the development of detailed procedures for the design of durable and sustainable building façades. This paper reviews the needed considerations in each stage of an optimal façade life cycle and compares them with the current available practices and discusses various safety-related issues, failure modes, and the risks involved throughout the system service life.

Perforated solar screens (PSS) are important to consider in building façade design because of their contribution to sustainability through daylighting. PSS façade design requires the consideration of many potential design alternatives that involve a large number of simulations. This paper presents a methodology in which the orthogonal and listing methods are integrated to predict a set of optimum PSS design variables to enhance the daylight availability in office buildings located in Seville, Spain. An orthogonal array was selected to perform a transverse comparison of the simulation factors mean effects and to find their statistical significance. Then, a standard level was fixed and used for further detailed analysis of a greater number of factor levels, measuring their daylighting contributions. The main advantage of the integrated method is the reduction of the number of simulations from 720 to 32, so the model could save considerable time and would help designers make early-design-stage decisions. With the optimization, the actual daylit area was increased by 29–57% and the overlit area was reduced by 36–57% relative to reference models with no PSS.

In most developing countries with a tropical climate, the benefits of insulating external masonry walls are often overlooked, and there is little or no effort to reduce the energy consumed. Apart from the comfort challenges, there is a concern of increasing energy consumption due to the rise in air temperatures and air-conditioning loads in building. Because building walls constitute the largest part of a building, there is a need to design sustainable building walls that can bring about energy efficiency and reduce cooling load by using the approach of wall insulation. Hence, this study involved the use of coconut-fiber insulation to achieve energy efficiency and thermal comfort in residential dwellings. Coconut fiber is a by-product from other industries and can be used for thermal insulation by placement in the cores of masonry block walls (i.e., as a loose-fill insulator). As such, an experiment was set up to estimate the effect of using coconut fiber–insulated masonry walls to achieve energy efficiency and thermal comfort in residential dwellings. The experiment made used of two identical physical small-scale envelope models to investigate the effects of using coconut fiber–insulated masonry walls. During the testing, the walls of the two models were insulated with coconut fiber as well as fiberglass board to determine their thermal benefits. Coconut fiber was found to be the preferred insulator because it has the required attributes to maintain thermal comfort and improve the energy efficiency of residential dwellings. The results also show that coconut fiber was able to improve the energy efficiency of the envelope physical models. This application is intended for low cost-residential buildings in a hot, dry climate.

Although the procurement of architectural and engineering (A/E) consultants has traditionally followed Qualifications-Based Selection (QBS), owners have begun to utilize cost evaluations with increasing regularity. A/E professional associations have widely viewed this as a threat to their profession and have established guidelines stating that owners should limit the weight of cost evaluations and use a two-envelope system to ensure an unbiased evaluation. This study investigated the application of these guidelines within 122 publicly procured A/E projects across North America. Selection outcomes roughly mimicked QBS, such that the highest qualified consultant was selected in the majority of cases; however, lower pricing did drive a minority of selections. The study also investigated the owner evaluation scores received by each individual consultant proposal within the data set (n = 804). Results contributed an understanding of the evaluation criteria that best differentiate between competing proposals, which informs owners in optimizing their evaluation schemes and guides consultants in their proposal development efforts. Finally, analysis revealed that greater consultant qualifications have no correlation with higher design cost, which contradicts owner-held perceptions that QBS results in higher costs.

The modeling and structural analysis of roof systems composed of metal plate–connected wood trusses (MPCWTs) require a detailed understanding of the rotational stiffness associated with various connections of the MPCWTs to the bracing elements and to the walls supporting the roof. The purpose of this study was to measure the rotational stiffness of several truss–bracing and truss–wall connections attached to MPCWTs to be used for structural modeling. Bracing included discrete and continuous bracing supporting the top and bottom chords of trusses. Truss–wall connections used single fasteners and proprietary sheet-metal connections. For the bracing connections, the rotational stiffness of the discrete bracing was greater than the rotational stiffness of the continuous bracing. Joist hanger–style truss–wall connections had greater rotational stiffness compared with hurricane ties or single-fastener connections. The rotational stiffness of hurricane ties was much greater when the applied torque caused a tension force in the hurricane tie versus a compression force. The rotational stiffness of hurricane ties from two different manufacturers was not significantly different.

The goal of this study was to survey the impact of design factors upon a mixed percentage of subsidized and market rate units. After content analysis of research, four physical factors, including unit number, site area, density, and house type, were extracted, and correlation analysis was performed between these factors and the percentage of subsidized units in 45 available mixed-income projects in the United States, Canada, and England. Next, we used frequency and crosstab to obtain the effects of the factors on the percentage of the subsidized units in three income levels (low, medium, and high). Findings indicated that when unit number and site area increase, the percentage of subsidized unit decreases, and the increase of density increases the percentage of subsidized units. Moreover, in large-scale projects, it is necessary to use lower density, and as a result, low-rise houses, while in small-scale projects, different types of houses can be used. Findings of the study clearly indicate that in designing and planning the mixed-income projects, we need to attend to physical factors as well as the cultural–social ones.