درخت حوزه‌های تخصصی

Density is a critical typology in determining sustainable urban built-form patterns. Built-form refers to the assemblage and arrangement of the building masses in a city reflecting the spatial layout of spaces. The relationship between density and urban character is also based on at certain densities (thresholds). In a wider sense, sustainable cities are a matter of density. Recent debates about the creation of more sustainable urban form, compact cities have led to a renewed focus on issues of density. The argument is that high density high-rise with low ground coverage or compact city form can offer a high quality of life while minimizing crime, possibility to provide adequate amenities, green and open spaces, accessibility and space consumption. However, the relationships of density and patterns built-form are not reasonably well developed and integrated into the urban design-planning processes in developing countries cities like Addis Ababa. On the hand, not many studies have been undertaken with regard to density in relation to patterns of built-forms. Therefore, this study aims to explore density in relation to patterns of built-form in the process of planning & design of urban spaces2. The analysis is based on the primary sources as well as secondary documents collected from the concerned agencies and related references. The findings illustrate that high density high-rise with low ground coverage patterns of built-forms can offer better possibilities for installing good spatial quality3 of urban spaces. It concludes with an overview of emerging thinking/implications where further efforts are required in the future

Architecturally, the Seljuqs' dominion makes a significant shift from the Pre-Islamic Sassanid squinches into a sophisticated transition mechanism employed to change the walls of a square chamber to an octagonal base to set a dome which this initiated a new construction methodology to hybridize the previous experiences of Sassanid domes with new architectural tendencies since the previous understanding of the transition zone was a makeshift in quality, not consistent enough for future architectural adventures in creating larger structures. Although a cursory investigation of transition zones of Seljuq dome chambers in some respects might reveals a fairly homogeneous framework, it has never meant the stagnation of architectural creativity in different parts of Seljuk territory. On the other hand, the typology and local schools of Seljuq transitions zones of dome chambers have not been thoroughly considered by geographical centralism in Iran. For a better understanding of the standardization of various techniques considered in Seljuq architecture between 11th and 12th centuries in order to spanning the cubic structure to a circular plan, this project is aimed to clarify three various schools of architectural articulation concerning transition zone in the Seljuq dome chambers.

Considering the determinant role of energy efficiency opportunities in the building sector, proposing guidelines and technical solutions in order to improve the thermal performance of glazing systems is in priority in Iran and other countries. In glazing systems, a substantial amount of radiative heat transfer results from absorption and emission. Applying low-E (low emissivity) coatings on the glazing system is a solution for reducing the radiative heat transfer by radiation in glazing systems, without a noticeable decrease of visible light transmittance. By selecting the proper glazing type, in a hot climate, the amount of solar heat gain can be reduced significantly. Vice versa, in cold climate, the heat loss by long wave radiation of inner surfaces can be reduced. In this paper, first, the thermal and optical characteristics of local clear and Low-E glasses have been measured in BHRC (Road, Housing & Urban Development (National) Research Center) laboratory, by the spectrophotometer and then the thermal performance of single and double glazing units, with and without low-E coating, in different orientations (North, South, East and West) are computed, compared and analyzed for cold (Ardebil) and hot (Bandar-Abbas) climates in Iran. The selection of these two cities is based on maximum heating and cooling degree day values obtained respectively for Ardebil and Bandar-Abbas. The simulation results indicate that using double clear glazing unit with low-E coating reduces the energy consumption significantly in very hot climates, using mostly electrical energy for cooling. In cold climates like Ardebil, double glazing with low-E coating has a minor impact on annual heating load, because of the great amount of thermal radiation, even in the cold season, the high cost of low-e coating and the considerable payback time, compared to the building life cycle.

The purpose of this research is to found the impact of built area and occupant number on winter gas consumption in the residential building sector of Iran, Shiraz.Sothe annually and monthly gas consumption data through 19 houses were analyzed to achieve the heating energy consumption and operation month.The average operation months of gas heating consumption were from first of November up to end of April and the average maximum monthly gas consumption of sample houses was in February. On the other hand, the case study houses have different built area from 80 t0 200 m2andoccupant number from 3 to 7 persons.It was concluded that the biggest and busiest houses did not consume the maximum annual gas consumption and so the smallest and low occupant ones about minimum consumption. Therefore, the samples heating consumption was not so related to the built area and occupant number. The occupant culture and behavior was more supposed to be related with energy consumption in residential sector of the city.