Production arrangements by US building and non‐building contractors: an update

The paper presents the results of the first phase of a long‐term study that addresses the determinants of the production arrangements by US building (commercial and residential construction) and non‐building contractors (transportation, environmental and industrial construction). Empirical and census data are used to understand the subcontracting and self‐performance practice of the considered contractors. The significant differences in their production arrangements are explained in terms of range of technological requirements and their relative importance within undertaken projects. Building contractors tend to subcontract much of their production, because of the relatively wider range of technological inputs of building projects and liability concerns. On the contrary, non‐building contractors self‐perform much of their production, because of the relatively narrower range of technological inputs of their projects and higher fixed investments in dedicated assets.     

The building volume with hygroscopic materials—an analytical study of a classical building physics problem

A global analytical solution covering all cases of a building volume with hygroscopic materials is given. The mathematical and physical simplifications and assumptions are quite modest. Isothermality is not assumed. Examples are rooms, attics, subfloor spaces and building cavities. All share the same physics describing the vapour pressure in the building volume and the moisture content in the hygroscopic materials as a function of building volume temperature and moisture emission rates, external vapour pressure and building volume ventilation levels, heat and mass transfer between the building volume and the hygroscopic materials, and heat and mass storage and transfer within the hygroscopic materials.     

The chicken or the egg? building anglican churches and building congregations in a victorian london suburb

ABSTRACT

There was lively debate in the mid-Victorian Church of England as to whether it was more effective for the construction of physical church buildings to precede the formation of a new parish and congregation, or whether it was advisable instead for the human church to precede the material one. This article explores the realities on the ground through a case study of the four new churches built in the North London suburb of Finchley between the 1840s and the 1890s. Where the church before congregation strategy was modestly costed and efficiently executed, it could, as at Holy Trinity East Finchley (1846) and St. Paul's Long Lane (1886), enable the rapid growth of thriving congregations. However, at Christ Church North Finchley (1868), where the congregation came first, subsequent pastoral activity was hampered for many years by the financial demands of an unnecessarily expensive building. At All Saints Durham Road (1892), initial plans to set up a congregation in an “iron church” were frustrated due to large donations conditional on the immediate erection of a permanent church. In a context of strong competition from Nonconformity, the desire to make a strong material statement of presence in a community was understandable, but its long-term consequences for the Church's mission were ambivalent ones.     

Retrofitting with vegetation recent building heritage applying a design tool—the case study of a school building

Several researches show the environmental and microclimatic benefits of the integration of vegetation in architecture; however the potentialities of vertical and horizontal greening systems to retrofit buildings are still not much investigated. The retrofitting project of the Barsanti Institute of Camogli (Genoa, Italy) is presented, a building dated back to the sixties with serious architectural and efficiency problems, located in a considerable landscape area. The development and application of a design tool (process tree), for horizontal and vertical greened surfaces, allows to evaluate the potentialities of vegetation to retrofit and to relate the encountered efficiency problems and the climate characteristics with the choice of plant species, system, and technology more suitable for the specific situation (of which environmental and economic impact are also evaluated) and to define a design approach for the systematic consideration of the many parameters involved.     

Region moves into fast lane of highway building

The Guangzhou-HuaxianExpressway, connecting theGuangzhou FoshanExpressway and the GuangzhouHuancheng (Ring) Expresswaywill play an important role inimproving economic co-op-eration and trade relations be-tween Huaxian, Guangzhouand Foshan in the Pearl RiverDelta.     

Dynamic thermal building analysis with CFD – modelling radiation

In an attempt to reduce the high computational effort required for dynamic thermal simulation of buildings using computational fluid dynamics (CFD) the authors have recently developed an adaptive freeze-flow method (i.e. freezing of flow equations over variable time periods). This article documents the work that has been carried out to predict the surface heat transfer in dynamic thermal building processes using CFD with particular focus on radiation. The Monte Carlo (MC) and discrete transfer (DT) radiation models were investigated and results compared with analytical solutions. The DT model has shown good performance whereas an unrealistic radiation distribution on the surfaces was observed when using the MC model. A further investigation of the DT model for the cooling of a solid wall has shown that the adaptive freeze-flow method is an efficient and accurate means of conducting dynamic thermal CFD simulations which involve radiation. Finally, application of the technique to a more realistic space comprising an uneven distribution of solar gain showed very good results when compared with a zonal dynamic thermal simulation program.     

Development of cork–gypsum composites for building applications

This paper presents an experimental analysis on a new composite material, cork–gypsum composite. It is shown that cork and plaster are mutually compatible and that a lot of new building materials can be made by mixing those materials in different volume fractions. Mechanical properties of the cork–gypsum composite have been measured. The acoustic absorption coefficient and thermal conductivity of this new composite have also been experimentally obtained and those values are reported for design purposes. Concerning the acoustical insulation characteristics, this composite is not a sound-absorbing material but a reflecting one, and it needs some kind of perforations to behave as an absorbing construction material for sound and noise. The thermal insulation properties are quite good as a result of the thermal conductivity tests. This new composite material is suggested for use in building applications as partitions.     

Computational evaluation of building physics—The effect of building form and settled area,microclimate on pedestrian level comfort around buildings

Wind discomfort and the dangers that the wind may lead can be harmful in terms of comfort conditions of both indoor and outdoor environment of the building/buildings to be constructed or just completed. The wind effects on a site can be divided in two as: mechanical wind effects and thermal wind effects. This study is specifically about mechanical wind stress and pedestrian wind comfort. Typically, the cause of frequent occurrences of strong wind at pedestrian area is primary related to the configuration of building structures and/or topography in the vicinity of the pedestrian area. Depending on the characteristics of the wind including magnitude, uniformity, ambient temperature, etc., the level of disturbance to users of pedestrian areas can be different. In this context, the regions where Necmettin Erbakan University (N.E.U.) temporary education buildings are located have a fairly intensive topography in terms of wind. Therefore, detailed analyses of the inside regions and the surrounding areas of education buildings in particular are performed in terms of microclimatic comfort and indoor energy recovery. Especially, the topography where the university campus temporary educational buildings are located has very high wind climate conditions comparing to the city of Konya, Turkey, climate conditions. In this study pedestrian level wind conditions around N.E.U. campus buildings and in urban areas and campus buildings settlements topography are analyzed by CFD FloEFD. The aim of the study is to analyze causes of wind nuisance in campus site area and around temporary education buildings, and compare and evaluate remedial measures. The results show that current campus settlement, around the buildings and amphi classes are seen to reach very discomforting levels in terms of in classroom comfort. Draft architectural campus temporary education buildings projects proposed by the author can improve on existing wind conditions where possible, and as a minimum, can not significantly degrade wind conditions especially when considering the safety criteria.     

Fire test data and building design—Some problem areas

Are the methods currently used to classify the combustibility of materials, the fire endurance of structural elements, and the flammability of interior finishes adequate as guide lines in designing fire resistance and fire protection into buildings? The author believes there are some fallacies in strict interpretation of accepted definitions and fire test results. He suggests that more comprehensive reporting of data, based on fire tests reflecting more closely the way materials and assemblies perform under actual fire conditions, would be extremely useful in applying sound fire protection principles in the design of fire-safe buildings.     

The accuracy of pre‐tender building cost estimates in Australia

A pre‐tender building cost estimate is an important piece of information when making decisions at the project planning and design stage. The important project characteristics influencing the accuracy of pre‐tender building cost estimates are examined and practical improvement for increasing the accuracy of estimates are considered. A quantitative approach is used to address the research problem. Analysis of data from 56 projects and from a postal questionnaire survey of 102 quantity surveying firms suggests that the accuracy of pre‐tender building cost estimates varies according to project size and principal structural material. When eight identified project characteristics are controlled in a multiple regression analysis, the accuracy of estimates is influenced by project size. The estimates of smaller projects are more biased than the estimates of larger projects. It was discovered that pre‐tender building costs are more often overestimated than are underestimated. Overestimated forecasts are incorrect by a larger amount than underestimated forecasts. Data analysis also revealed that the accuracy of pre‐tender building cost estimates has not improved over time. The majority of the respondents are somewhat dissatisfied with the accuracy of estimates in the industry. Probability estimation and simulation of past estimates, reducing quantity surveying and cost engineering skill turnover, incorporating market sentiments into estimates, early involvement of the quantity surveyor at the brief stage, and proper documentation of experience gained in the estimation of projects should help firms increase the accuracy of estimates for new projects.     

DeST—An integrated building simulation toolkit Part II: Applications

This is the companion paper of part I of DeST overview. DeST was developed as a building simulation tool with the aim of benefiting both design of and research on building energy efficiency. During its development, DeST has been applied to many projects, development of building regulations, and research. This paper gives examples of several areas in which DeST has been applied, including building design consultation, building commissioning, building energy conservation assessment, a building energy labeling system, and scientific research. Examples from a demonstration building are presented to demonstrate the entire process of aiding design with DeST. Additional projects and regulations are also mentioned to introduce other applications of DeST.     

Muscular strain in ‘heavy’ and ‘light’ building work

In this Finnish study, the causes and frequency of musculoskeletal strain among concrete reinforcement workers and painters on house maintenance are analysed from observations at 30s intervals, from accident report forms and from interviews about unreported minor accidents. Various measures are then suggested to prevent the problems revealed, including careful work planning and site layout, and care over means of access to the work point.     

Condition assessment of building façades based on hazard to people

Abstract

To make periodic inspections of the buildings is useful to quantify the extent to which deficiencies are severe or not, in order to facilitate decision making and prioritize interventions. In previous works by the authors is proposed a scale of gravity of damages in buildings, with the aim of being of widespread and of common use among professionals. This scale is applied through the direct assignment (DA) methodology, based on the generic definitions of each degree. It is demonstrated and characterized the existence of certain level of variability among technicians, when assigning gravity values using DA methodology, due to the fuzzy condition of the attribute to be evaluated. The main goal of this paper is to propose a methodology to assign values of gravity, based on hazard for people of detachments from the façade, by using measurable parameters and mathematical functions. The final objective is to reduce the level of variability among inspectors when assessing the condition state of a building façade. The proposed methodology is named system of evaluation of façades (SEF). The methodology can be also extended to the assessment of other building systems as structures or roofs and other type of infrastructures.     

TOBUS — a European diagnosis and decision-making tool for office building upgrading

The TOBUS (a decision-making tool for selecting office building upgrading solutions) methodology and software have been developed as a result of a 2-year European research project, involving eight European institutions, in the frame of the JOULE III programme of the European Commission (EC), Directorate General XII. A structured diagnosis scheme enables architects and engineers to simultaneously handle the entire complex process of office building refurbishment or retrofit with respect to deterioration, functional obsolescence of building services, energy consumption and indoor environmental quality. The software tool can then be used to define the most appropriate and cost-effective actions, to elaborate consistent refurbishment scenarios and calculate a reasonable investment budget in the early stages of a refurbishment project. This paper provides an overview of the work performed in TOBUS and an overview of the methodology and final deliverables of the project.     

Dimension stone for building façades: methodology for structural design

The importance of a careful selection of rocks used in building façade cladding is highlighted. A simple and viable methodology for the structural detailing of dimension stones and the verification of the global performance is presented based on a Strap software simulation. The results obtained proved the applicability of the proposed structural dimensioning methodology which represents an excellent simple tool for dimensioning rock slabs used for building façade cladding. The Strap software satisfactorily simulated the structural conditions of the stone slabs under the studied conditions, allowing the determination of alternative slab dimensions and the verification of the cladding strength at the support.     

“Adaptive radiation” optimization for climate adaptive building facade design strategy

This paper introduces an evolutionary algorithm methodology to solve facade optimization problems in different climates. The algorithm is based on the improvement of simple Genetic Algorithm (GA). The concept of Adaptive Radiation (AR) is derived from the biological process of adaptation where specific species are evolutionarily adapted to their immediate ecological niches. This algorithm obtains near global optimal solutions in significantly less computation time than simple GA. AR is implemented in three different climates in the United States to demonstrate its robustness and efficiency. Climate adaptive facade design strategies for these climates are illustrated based on the optimization results.     

Materials in Germany’s domestic building stock: calculation model and uncertainties

Building stocks are the dominant consumers of resources within national economies. Correspondingly, there is high demand for improved knowledge of material stocks and flows in the built environment. Material flow analysis is well suited to meet this demand. Although numerous studies have been conducted on this topic over recent years, these frequently lack applicability and transferability due to insufficient documentation or treatment of uncertainties. A new approach is presented here to calculate material stocks and flows for domestic buildings using the example of multi-family housing (MFH) in Germany. The approach is critically examined to determine its validity. The calculation process involves four steps: (1) building types are classified according to building age; (2) highly specific material composition indicators (MCIs) are calculated for the respective building types; (3) the total material stock as well as inflows and outflows are derived from the total floor space of Germany’s MFH; and (4) validity tests are performed to quantify uncertainties. The main results are age-based MCIs for MFH, the total material mass as well as quantitative information on parameter- and model-related uncertainties. Conclusions are drawn on the validity of results, the scalability and applicability of the model and its implementation, along with potential model refinements.     

Exploring the synergy of building massing and façade design through evolutionary optimization

In performance-based architectural design optimization, the design of building massings and façades is commonly separated, which weakens the effectiveness in performance improvement. In response, this study proposes a hybrid massing-façade integrated design generation and optimization workflow to integrate the two elements in an evolutionary design process. Compared with the existing approaches, the proposed workflow emphasizes the diversity of building design generation, with which various combinations of building massing forms and façade patterns can be systematically explored. Two case studies and a corresponding comparison study are presented to demonstrate the efficacy of the proposed workflow. Results show that the optimization can produce designs coupling the potential of building massings and façades in performance improvement. In addition, the optimization can provide information that supports early-stage architectural design exploration. Such information also enables the architect to understand the performance implications associated with the synergy of building massing and façade design.     

Natural cooling strategies efficiency in an office building with a double-skin façade

In these last years, a great deal of interest has been devoted to double-skin façades due to the advantages claimed by this technology (in terms of energy saving in the cold season, high-tech image, protection from external noise and wind loads).The advent of computers and other office equipment increased the internal heat gains in most offices. Highly glazed façade become very common. This, together with the extra heat gains from the electric lighting made necessary by deep floor plans, and the wider use of false ceilings, increased the risk overheating.To preserve comfort and reduce cooling loads, it is important to apply natural cooling strategies.This article examines the efficiency of the various strategies in an office building with and without a double-skin façade during a sunny summer day. It mainly studies the natural night ventilation possibility in related to the double skin orientation and the speed and orientation wind.In this matter, we choose to study a multistory double-skin facades behavior. Simulations were realized with TAS software on the building proposed in the frame of the subtask A of the Task 27 (Performance of solar facade components) of the International Energy Agency, Solar Heating and Cooling Program.