Selection of low-e windows in retrofit of public buildings by applying multiple criteria method COPRAS: A Lithuanian case

Calculations of building retrofit effectiveness have shown that the replacement of original windows with new ones is not as effective in terms of heat energy saving as are the insulation of a roof, walls and other improvements because the investments are large and take a long time to be repaid. However, in addition to energy saving, window replacement improves the indoor climate of the building, its interior and architectural appearance as well as its market value. The sequence of building operations determines when the replacement of windows should be done. When financial resources are limited, managers of public buildings often begin the renovation of a building's envelope with the replacement of windows. The client faces some problems in choosing among the great variety of windows to satisfy his/her needs, especially with respect to the cost-quality relationship. The method of multiple criteria complex proportional assessment (COPRAS) developed by the authors aims at solving the above-mentioned problems. The solutions based on multicriteria analysis allow for a more rational and realistic assessment of customer's needs as well as cutting down window renewal costs. In this paper, practical example (key-case) of selecting a contractor for the replacement of windows in the main building of Vilnius Gediminas Technical University (VGTU) is presented as a part of its retrofit multivariant design.     

Hauptbahnhof Dresden – Instandsetzung und Umbau der Bahnsteighallen

The refurbishment of Dresden Main Station. Refurbishment Dresden's historic main station has been unique, due to the large size of the new 30.000 m² membrane roof and the requirement to carry out all works while the station continued to offer a normal service for passengers. The architectural design, by Foster and Partners, was based on the idea of “wrapping” the structure with a PTFE‐coated glass‐fibre membrane. The existing steel structure has also been refurbished and reinforced in order to support the new roof. One of the most significant engineering challenges faced by the engineering team was to manage the load transfer from the membrane, through the existing steelwork into the foundations. The project's design brief was to keep and restore as many of the original building elements as possible, such as the structure and facades. When it was necessary to replace building components, contemporary solutions were chosen which were in keeping with the originals, in order to preserve the character of the station halls. The completed project respects and emphasises the station's history, while incorporating state of the art techniques that represent the development of Deutsche Bahn.     

Drivers and benefits for district-scale energy refurbishment

Existing building stock is responsible for a significant share of energy consumption in cities, consequent emissions, and effects on climate change. Energy refurbishment of buildings can have an essential contribution to sustainable strategies of cities in Europe. District-Scale Refurbishment (D-SR) has many benefits compared to single building refurbishment, but some barriers have delayed the realisation of district-scale projects. This article aims to explain the importance of district-scale approaches for energy-efficient refurbishment and presents the findings related to the need for a new-type of role needed to accelerate district-level energy-efficient refurbishment projects, defined as an “activator”. Threefold methodology was applied to conduct this study including (1) a literature review to analyse issues that enable or hinder district-scale energy refurbishment of existing buildings, (2) twenty-five semi-structured interviews were carried out of pioneering representatives of architectural engineering and construction (AEC) in Finland and the questionnaire was designed to encompass Osterwalder's business canvas approach. Thematic findings were identified based on the qualitative results of the interviews.The results of this study demonstrate that while district-scale refurbishment is seen beneficial in many aspects, it requires new roles, and an activator is needed to initiate and possibly lead the process. At the same time, the role of the municipality emerged as extremely important as an enabler by supporting flexible town-planning, open information, strong support for citizens' participation processes and by providing incentives for starting the process. The optimum profile of an activator is very demanding, requiring skills in process understanding, networking, and collaboration, in addition to expertise in energy solutions and technologies. This role could be taken by, e.g. contractors, project managers or engineering companies. The major challenge remains concerning who would pay for the role of an ‘activator’ during the initial stages of D-SR. This could be solved e.g. through a national incentive or the activator could be hired by the municipality. The value proposition should be for the end-users and could be based on (a) saving or increasing the value of a residential flat, (b) improving the living environment and increasing the attractiveness of the district, (c) improving well-being, or (d) easiness of refurbishment process.     

Decision‐making in a model‐based design process

Decisions early in the design process have a big impact on the life cycle performance of a building. The outcome of a construction project can be improved if different design options can rapidly be analysed to assist the client and design team in making informed decisions in the design process. A model‐based design approach can facilitate the decision‐making process if the design alternatives' performances can be evaluated and compared. A decision‐making framework using a performance‐based design process in the early design phase is proposed. It is developed to support decision‐makers to take informed decisions regarding the life cycle performance of a building. A scenario is developed in order to demonstrate the proposed framework of evaluating the different design alternatives' energy performance. The framework is applicable to decision‐making in a structured design process, where design alternatives consisting of both objective and subjective evaluation criteria can be evaluated.     

Energetische Sanierung von Schulgebäuden in den neuen Bundesländern – Sanierungsprojekt Förderschule Rathenow

Energy efficiency improvements for school buildings in Germany's new federal states; Rathenow special school refurbishment project. Current energy saving measures for existing buildings focus on refurbishment of schools and other educational buildings. The building described in this article represents the standard type of a large‐panel construction series in the new federal states. Due to the large number of buildings (540) constructed in this way the project can act as a model for similar projects. Initial studies indicated that structural refurbishment measures for these buildings are required as a matter or urgency. The energy performance calculations for the building showed good agreement between the calculated demand values and actual heating energy consumption values and can serve as basis for predictions of energy savings through various refurbishment measures. The new DIN 18599 calculation standard enables significantly more differentiated consideration of boundary conditions such as occupied periods, occupancy levels, internal heat sources, and the effect of night setback. Based on comparative calculations, different refurbishment concepts can be developed and assessed.     

A multi-objective feedback approach for evaluating sequential conceptual building design decisions

Conceptual design decision-making plays a critical role in determining life-cycle environmental impact and cost performance of buildings. Stakeholders often make these decisions without a quantitative understanding of how a particular decision will impact future choices or a project's ultimate performance. The proposed sequential decision support methodology provides stakeholders with quantitative information on the relative influence conceptual design stage decisions have on a project's life-cycle environmental impact and life-cycle cost. A case study is presented showing how the proposed methodology may be used by designers considering these performance criteria. Sensitivity analysis is performed on thousands of computationally generated building alternatives. Results are presented in the form of probabilistic distributions showing the degree to which each decision helps in achieving a given performance criterion. The method provides environmental impact and cost feedback throughout the sequential building design process, thereby guiding designers in creating low-carbon, low-cost buildings at the conceptual design phase.     

代际互助模式下东北寒地城市住宅改造研究

在严酷的气候背景及社会发展背景下,东北寒地城市具有大量既有住宅亟待改造,全面的改造不仅仅是建筑节能性能的提高,也包含居住模式变化对建筑空间环境产生的改造要求。近年来,我国应对老龄化趋势在人口政策方面做出了大幅度调整,通过解析东北寒地城市既有住宅的本质特征及适老化需求特点,分析其改造关键问题,以积极老龄化理念为指引,发掘"代际互助模式"在该地区住宅改造中应用的可行性,建构基于此模式的东北寒地城市既有住宅改造研究平台。     

Applying multi-objective genetic algorithms in green building design optimization

Since buildings have considerable impacts on the environment, it has become necessary to pay more attention to environmental performance in building design. However, it is a difficult task to find better design alternatives satisfying several conflicting criteria, especially, economical and environmental performance. This paper presents a multi-objective optimization model that could assist designers in green building design. Variables in the model include those parameters that are usually determined at the conceptual design stage and that have critical influence on building performance. Life cycle analysis methodology is employed to evaluate design alternatives for both economical and environmental criteria. Life cycle environmental impacts are evaluated in terms of expanded cumulative exergy consumption, which is the sum of exergy consumption due to resource inputs and abatement exergy required to recover the negative impacts due to waste emissions. A multi-objective genetic algorithm is employed to find optimal solutions. A case study is presented and the effectiveness of the approach is demonstrated for identifying a number of Pareto optimal solutions for green building design.     

Housing refurbishment contractors selection based on a hybrid fuzzy-QFD approach

With low demand for new construction, limited land usage, and being aware of sustainability, the refurbishment market has grown greatly and has become more in demand in the construction industry. Most refurbishment work, however, involves a high level of risk, uncertainty, and coordination, which are likely to cause asymmetric information between contractors and residents in a refurbishment process. Most private refurbishment contractor selections are usually based on word-of-mouth referrals that lack a systematic and objective assessment method. This study proposes a hybrid approach combining fuzzy set theory and quality function deployment (QFD) to establish a housing refurbishment contractor selection model. With this model, residents can select an optimal refurbishment contractor according to requirements. To test the effectiveness of the proposed model, a known multiple criteria decision-making method, PROMETHEE, is applied to compare the results of contractor selections. The result reveals that the proposed hybrid fuzzy-QFD approach can be expected to be successful and has potential for handling multiple criteria decision-making problems.     

An investigation of the existing situation and trends in building energy efficiency management in China

According to the Chinese State Council's “Building Energy Efficiency Management Ordinance”, a large-scale investigation of energy efficiency (EE) in buildings in contemporary China has been carried out in 22 provincial capitals and major cities in China. The aim of this project is to provide reliable information for drawing up the “Decision on reinforcing building energy efficiency” by the Ministry of Construction of China. The surveyed organizations include government departments, research institutions, property developers, design institutions, construction companies, construction consultancy services companies, facility management departments, financial institutions and those which relate to the business of building energy efficiency. In addition, representatives of the media and residents were also involved. A detailed analysis of the results of the investigation concerning aspects of the current situation and trends in building energy consumption, energy efficiency strategy and the implementation of energy efficiency measures has been conducted. The investigation supplies essential information to formulate the market entrance policy for new buildings and the refurbishment policy for existing buildings to encourage the development of energy efficient technology.     

Bestandssanierung aus einer Hand: ein zukunftsweisendes Kooperationsmodell für die Gebäudesanierung

Building refurbishment from one source: a forward‐looking cooperation model. Owners of private and smaller commercial building often feel out of their depth when it comes to technical and organisational aspects of comprehensive energy refurbishment. This article examines barriers for energy‐related upgrades and proposes a cooperation model for SMEs and building trade company as a countermeasure. “Building refurbishment from one source” aims to cover all aspects of energy‐related upgrades of residential buildings and lead to wider acceptance of energy‐related upgrades of existing buildings. The article summarises the findings from surveys and interviews and feedback from respondents. The study focuses on owner‐occupied residential build‐ings. The findings can be used to assist other cooperation schemes. Free cooperation between friendly companies and project‐related partnerships proved successful. From a client perspective the preferred option is a solution where one of the partner companies acts as main contractor. This “small” cooperation solution was well received by clients and many building trade companies and should be emphasised more strongly in the context of energy‐related building upgrades. Specimen contracts would encourage the establishment and aid continuity of such cooperation schemes.     

Historic Building Information Modelling: performance assessment for diagnosis-aided information modelling and management

Building Information Modelling, new paradigm of digital design and management, shows great potential for the refurbishment process, as it represents a possible way out of criticalities that occur in documentation and preservation of existing assets, if connected to cognitive automation. The combination of BIM with automation systems improves the quality control during diagnosis, design and work execution, and the labour savings, which is particularly relevant for rapid intervention in case of hazardous conditions.Therefore, the paper is going to address a methodological discussion concerning complete “as-built” parametric models of historical buildings, supporting the design of refurbishment and conservation interventions. Although some reviews of the state of the art exist on the topic of Historic Building Information Modelling, the present research introduces a different perspective on HBIM modelling, with diagnosis and performance assessment as key-aspects, in terms of automating performance assessment.Specifically, from the data collection of contributions regarding HBIM/BIM, diagnostics and monitoring on existing buildings and infrastructures, a critical review by selected criteria is developed. Nevertheless, general methods and tools for information management and exchange tasks in BIM are briefly described as well, since they are considered useful for future developments of HBIM approach. The core of the critical analysis is focused on the scientific and technical relations among HBIM models, diagnosis and performance assessment features. In addition, the review identifies specific activities and relative tools and methods for knowledge acquisition and semantic enrichment.Finally, gaps in knowledge of the current literature are outlined and discussed, with specific focus on performance assessment in HBIM. In this regard, a new methodology toward Diagnosis-Aided Historic Building Information Modelling and Management (DA-HBIMM) is proposed as a framework to be developed in order to address smart knowledge acquisition, collection and notification of assessed performances and eventual risks, by cognitive automation and artificial intelligence, in the near future.     

>Cities and People,A Social and Architectural History

In the late 1950s the Bacardi Rum Corporation commissioned Ludwig Mies van der Rohe to design an office building in Mexico. Bacardi used the commission to shape its image as a sophisticated and cosmopolitan enterprise, as it reinvented itself in the aftermath of the Cuban Revolution. The Bacardi project serves as a case study of corporate patronage of modern architecture in Latin America, marking a moment when both the image and organization of Mies's architecture helped build a reliable, mainstream international brand. Paradoxically, Mies's Bacardi building would also become part of a “mix” of architectural commissions that would include emerging alternatives to International Style modernism.     

Cost modelling in underpinning projects

Large refurbishment projects are characterized by highly varied costs from one project to another. In Finnish underpinning, only retrospective analysis of costs has been available for the owner’s decision process. In order to develop tools for pre‐tender cost estimating and for comparison of different design solutions and evaluation of tenders of the underpinning project, two different cost models have been developed for research. In both models developed, the minimum data required is the pile length. In the more detailed model, the assessment is based on the design solution, including known pile types and the load transfer classification. Both models are easy to use, and the percentage of explained variance is fairly good in the more detailed model.     

建筑材料慕课建设与教学实践

在全球信息技术和教育信息化的推动下,以慕课(MOOC)为主要形式的大规模开放式在线课程成为教育界的重点发展方向。为提高公共服务水平,促进教育公平与课程教学改革,教育部《关于加快建设高水平本科教育全面提高人才培养能力的意见》指出,要大力推进慕课和虚拟仿真实验,大力推进和发展高质量慕课建设。以建筑材料慕课为例,从建筑材料课程基本情况及特点、建筑材料慕课资源建设和建筑材料慕课教学设计及实施效果分析三方面论述了优质慕课资源的建设思路,并在慕课平台上开设社会公共班,在教学探索过程中得到了关于课程内容、教学资源、教学模式及线上考核方面的宝贵经验,为日后建筑材料慕课和其他学科的慕课开展奠定实践基础。     

A life-cycle energy analysis of building materials in the Negev desert

Environmental quality has become increasingly affected by the built environment—as ultimately, buildings are responsible for the bulk of energy consumption and resultant atmospheric emissions in many countries. In recognizing this trend, research into building energy-efficiency has focused mainly on the energy required for a building's ongoing use, while the energy “embodied” in its production is often overlooked. Such an approach has led in recent years to strategies which improve a building's thermal performance, but which rely on high embodied-energy (EE) materials and products. Although assessment methods and databases have developed in recent years, the actual EE intensity for a given material may be highly dependent on local technologies and transportation distances. The objective of this study is to identify building materials which may optimize a building's energy requirements over its entire life cycle, by analyzing both embodied and operational energy consumption in a climatically responsive building in the Negev desert region of southern Israel—comparing its actual material composition with a number of possible alternatives. It was found that the embodied energy of the building accounts for some 60% of the overall life-cycle energy consumption, which could be reduced significantly by using “alternative” wall infill materials. The cumulative energy saved over a 50-year life cycle by this material substitution is on the order of 20%. While the studied wall systems (mass, insulation and finish materials) represent a significant portion of the initial EE of the building, the concrete structure (columns, beams, floor and ceiling slabs) on average constitutes about 50% of the building's pre-use phase energy.     

Modeling building projects as a basis for change control

Changes made in building projects during their design and execution are a major cause for delays, cost overruns and deviations from performance requirements. The impact of changes on the project often becomes clear only after their implementation in the project. At that stage it is difficult to make adjustments or consider alternatives. A timely recognition, by the project team, of the implications of proposed changes can lead to a reconsideration of the changes, so that the completed project would still meet the client's objectives.This paper presents an ongoing research project for the development of a model of building projects, as a basis for change control. The model facilitates an automatic identification of the possible consequences of changes when they are first proposed, prior to their implementation in the design and planning of the project. The model utilizes available sources of project information in order to identify the impact of changes on the primary client objectives of cost, schedule and performance.The proposed model's feasibility was examined through its application in a case-study. The model was used to identify, in retrospect, the possible impact of proposed changes in a case study of a building project. The consequences of different change scenarios were quickly identified by tracing the relationships between the elements of the project. In reality, these consequences became clear only after the changes were fully implemented.     

BIM-based automated design and planning for boarding of light-frame residential buildings

Building information modelling technology provides a game-changing solution to address the challenges encountered in the AEC industry. However, this technology currently is not sufficient to fulfil the needs of construction practitioners in terms of proactive design and planning for boarding of light-frame residential buildings. This is partially due to the fact that boarding design and planning requires trades' know-how and substantial manual effort in developing the building information models. Current manual and ad hoc decision making for boarding of light-frame buildings leads to the generation of a significant amount of material waste. This research thus proposes a rule-based automated building information model (BIM) approach for designing boarding layout and planning material sheet cutting, resulting in practically feasible solutions with minimal material waste. In this research, object-based computer-processable layout design rules are comprehensively formalised based on trades' know-how. On this basis, rule-based design algorithms are further developed and integrated with mathematical algorithms in order to automatically generate design and planning alternatives while minimising material waste. Rich information in the BIM is leveraged to automate the rule-based boarding design and planning. A prototype system is developed based on Autodesk Revit via Application Programming Interface. A typical wood-framed residential building is used as a case study to test the developed prototype system. The results show the proposed approach successfully preserves the know-how of senior trades people while also minimising material waste in automating the boarding design and planning.     

Clients’ assessment of architects’ performance in building delivery process: Evidence from Nigeria

The overall intent of this research is to provide architects with information that can be used to improve their performance so as to optimally satisfy the client's requirements and achieve high-quality overall project performance in Nigerian construction industry. Architect performance criteria were identified based on literature within the domain of architect responsibilities. The assessment of architects’ performance was carried out through a questionnaire survey of clients of recently completed building projects in Nigeria. Analysis of data includes comparison of criteria using importance–performance index analysis. Factor analysis was carried out on criteria where architects are falling below average, to group and explore the latent structure of the criteria in the data. The results showed that the architect needs to focus on management skills and ability, buildability, design quality, project communication, project integration and client focus. These results would encourage architects to perform better within their full responsibilities in the building delivery process and deliver high-quality projects within Nigerian construction industry.     

A model for assessing occupant flow in building spaces

As buildings are becoming larger in size, the need to efficiently plan and predict the occupant movement in building spaces is gaining more attention and importance. Occupant movement in large public buildings such as train stations, airports, universities, hospitals, and shopping centers needs to be carefully analyzed and predicted for safety and also for other issues such as the level of service (LOS), comfort, and short-term planning. Currently there are many detailed occupant/pedestrian simulation models that can predict the level of service in corridors and other dynamic spaces in the building in terms of occupant flow. However, these simulation models require a well-formulated design with detailed design features. In addition, significant investment in time and effort is required in order to build the models for simulation analysis. Therefore, there is a need for a simple and quick analysis method to aid in the sizing and design of building spaces during the early design stages so that these spaces can accommodate occupant flow efficiently and safely. This paper presents a method to evaluate the LOS of occupants in dynamic buildings spaces without the need for building and running detailed simulations, so that designers can understand how well a particular space accommodates occupants' movements and activities early on in the design phase. The proposed method can be used to determine the occupant flow density in a wide array of building layouts and designs as it correlates to the level of service. A mathematical model that offers a closed-form formula for sizing space for occupant flow is developed. The model is presented in this paper and validated using real-life data. Results should be of interest to practicing architects as well as researchers.