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- Shadram, Farshid, 1987-
(författare)
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Assessment and optimization of life cycle enrgy use in buildings
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Buildings account for 40% of all energy use in European countries. The European Union (EU) therefore encourages member states to adopt Energy Efficiency Measures (EEMs) and implement energy-efficient practices during building design to minimize the energy use of buildings. However, recent studies have shown that energy-efficient buildings may not always outperform conventional buildings in terms of Life Cycle Energy (LCE) use. This is mainly due to the trade-off between embodied and operational energy, and a reliance on EEMs that reduce operational energy while sometimes increasing embodied energy and LCE use. To improve buildings’ environmental performance, the impact of different EEMs on buildings’ energy use needs to be assessed from a lifecycle perspective, and methods for identifying optimal combinations of EEMs that minimize LCE use should be developed. Ideally, these methods should be integrated with building information modelling (BIM) to enable seamless data exchange and to help Architecture, Engineering and Construction (AEC) practitioners make optimal design decisions relating to EEMs. The work presented in this thesis had two overall objectives: (1) to explore the scope for developing BIM-supported method(s) for assessing and optimizing the impact of EEMs on buildings’ LCE use during the design process, and (2) use the BIM-supported method(s) for exploring the impact of various EEMs that are implemented and modified during the building design process on the buildings’ LCE use.The work presented in this thesis is based on an exploratory research design involving iterative cycles of (1) problem identification, (2) method development, (3) method examination, and (4) theory suggestion. In step 1, problems were identified by conducting literature studies and workshops with AEC practitioners, and analyzing archival data. In step 2, prototyping was used to develop methods to overcome the identified problems. In step 3, the applicability of these methods (or prototypes) was tested in case studies on actual and hypothetical building projects. Three case studies were conducted – one dealing with a low energy dwelling located in Kiruna, Sweden; another dealing with a multifamily residential building in Uppsala, Sweden; and a third dealing with a hypothetical multifamily residential building in Stockholm, Sweden. In step 4, the results were compared to existing theories to strengthen existing knowledge and identify previously unrecognized findings.In relation to the first objective, the results obtained show that the factors and activities required to develop BIM-supported method(s) for assessing and optimizing the impact of EEMs on a building’s LCE use during the design phase are:• A database that stores external and building project data (e.g. BIM data) and links it to be used for assessment and optimization, providing access to the data whenever needed.• The development of interfaces using middleware applications to ensure interoperability and seamless automated exchange of information between BIM and other systems.• Predefined objects (i.e. building part and component recipes) that are stored in a database and linked to inventories and Environmental Product Declarations (EPDs) for the relevant materials, enabling assessment of the buildings’ embodied energy and LCE use.• The application of multi-objective optimization techniques (e.g. Pareto-based genetic algorithms) to identify optimal solution(s) for EEMs that minimize (optimize) the building’s LCE use.In relation to the second objective of the thesis, the results obtained indicate that:• EEMs that are implemented and modified during the detailed design phase have much less influence on the building’s LCE use than those implemented in the early design phase. Highly influential EEMs related to the early design phase which were tested herein were the building’s shape, orientation, Window to Wall Ratio (WWR), and the selection of materials used in the building envelope.• Generally, thickening roof insulation has a strong beneficial effect on LCE use for buildings in Sweden.• For buildings using energy sources with high primary energy factors, the most effective way to reduce LCE use may be to implement many EEMs that reduce operational energy use. However, this approach may be less helpful for buildings using greener energy sources because in such cases the embodied energy may have a greater effect on the final LCE use.• The embodied energies of materials in the same class can vary significantly between suppliers. Such differences in embodied energy can be identified by considering the suppliers’ EPDs, the energetic contributions due to their mode of transportation from the site of production, and the distance between the site of production and the construction site.• If the developed optimization approach is used to identify optimal combinations of EEMs in the early design phase, designers can freely choose from a wide range of building shapes without greatly affecting LCE use. However, without early phase optimization, designs that use different building shapes may exhibit significantly different LCE use values.The results provide both theoretical and practical contributions that may be useful to researchers and AEC practitioners seeking to develop BIM-supported design processes and to reduce buildings’ LCE use by adopting appropriate EEMs. The results also show that embodied energy can be a major component of a building’s LCE use if the building’s design relies heavily on EEMs designed solely to reduce operational energy use. Policy makers and governmental bodies are thus advised to update regulations and building codes to reflect the importance of embodied energy so as to minimize the LCE use of new and retrofitting building projects.
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| 3. |
- Jensen, Patrik, et al.
(författare)
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Applying products in product platforms in the AEC firm
- 2014
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Ingår i: Computing in civil and building engineering. - Reston, VA : American Society of Civil Engineers (ASCE). - 9780784413616 ; , s. 1062-1069
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Konferensbidrag (refereegranskat)abstract
- A 5 step method for developing configurable “products in product” platforms to be used in an engineer-to-order (ETO) design process is proposed. The idea is based on the transformation of typical product architectures into modular design platforms where standard and variant modules are identified and developed. The platform modules can then be configured and combined with traditional design methods to meet the project specific requirements in the design process. Based on 1193 project designs, several configurable “products in product” were identified and developed in a real case study using the proposed method.
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| 5. |
- Simonsson, Peter, et al.
(författare)
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'Learning to see' the effects of improved workflow in civil engineering projects
- 2012
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Ingår i: Lean Construction Journal. - 1555-1369. ; , s. 35-48
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Tidskriftsartikel (refereegranskat)abstract
- Research Question/Hypothesis: Value Stream Mapping (VSM) can, independent of work repetition, improve the performance of civil engineering projects by allowing the site management to visualize the flows of materials, resources and information.Purpose: The purpose is to show how VSM can be used by on-site practitioners to see the day-to-day flow of work, to understand the effect of straight-forward improvements to workflow, and to see the effect of applying industrialized working methods.Research Method: Applicability of VSM to civil engineering is examined through the fixing of reinforcement in two bridge construction projects. A traditional bridge was used to map (current state) and improve (future state) workflow. The potential of modern production methods are then analyzed in a second bridge project (ideal state).Findings: Allowing the site management to visualize and to see workflow improves the work performance of the two studied bridges. Addition of easy to understand and calculable metrics for lead time, inventory level and manufacturing costs, emphasize the potential savings of reactive and proactive workflow measures (≈ 80-90 %).Limitations: The paper considers fixing of reinforcement in two bridge construction projects. Additionally, the so-called future state bridge was not actually constructed, i.e. the savings stated for the future state, even if reasonable, are an approximation.Implications: The framework to visualize current, future and ideal workflow provides a framework to extend the VSM methodology to civil engineering projects.Value for practitioners: To overcome the sub-optimized mindset in civil engineering that repeatedly leads to the same practice, the paper proposes a straightforward and easy to use framework to visualize and analyze effects of workflow improvements.
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| 6. |
- Yang, Bin, et al.
(författare)
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Outdoor thermal comfort under subarctic climate of north Sweden : a pilot study in Umeå
- 2017
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Ingår i: Sustainable cities and society. - : Elsevier BV. - 2210-6707. ; 28, s. 387-397
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Tidskriftsartikel (refereegranskat)abstract
- Outdoor microclimate is important to determine the quality of outdoor spaces. Swedish people cherish summer period and prefer more outdoor activities in summer because of long winter with harsh outdoor environments. People in urban areas use parks for recreation and outdoor activities frequently in summer. Under subarctic climate, limited studies have been performed to explore the effect of microclimate environments on usage of outdoor spaces such as parks. The study explored the relationship of microclimate environments, park use and human behavioral patterns in urban area of Umeå, Sweden, which is under subarctic climate. Observations of naturally occurring behavior were recorded. Structured interviews, based on specially designed questionnaires, were performed during July to August in 2015. Measurements of objective parameters for microclimate environments, including air dry bulb temperature, relative humidity, wind speed, solar radiation and globe temperature, were performed. Human subjective responses from the questionnaire survey were compared with objectively measured results. 49% of local persons still prefer higher solar radiation even under "slightly warm" Thermal Sensation Vote (TSV), which reflects their high expectation to solar radiation. Local persons in Umeå, who expose themselves to a wider climate, are more adapted to subarctic climate than non-local persons. Practical implications: The pilot study demonstrated that wind attenuation together with strong sunshine can improve Thermal Sensation Vote (TSV), which could be realized by specially designed hump terrain for attenuating wind without shading effects. The results will be used for optimizing design of urban outdoor environments such as parks under subarctic or arctic climate.
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| 7. |
- Jansson, Gustav, et al.
(författare)
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Requirements transformation in construction design
- 2010
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Ingår i: CIB W78 27th International Conference on Applications of IT in the AEC Industry & Accelerating BIM Research Workshop.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Transformation of performance requirements to technical solutions and production parameters is central for architects and engineers in the design process. Construction industry suffers from low efficiency in design, and the information flow creating bottlenecks for the production process. Tracing and managing information through design process needs standards both for requirements and Building Information Models in a life cycle perspective. Structuring functional requirements is of great interest for the construction industry and especially for companies developing industrialised housing system that often have control over the whole manufacturing process. The delivery of a new low-carbon economy in Europe puts pressure on the construction industry to reduce the energy consumption for buildings. Therefore is one national standard for energy requirements tested on a building system and evaluated in an Information and Communication Technology-environment (ICT) that supports the design process for industrialised construction. The result of the research shows that the transformation of requirements to technical solutions needs functionality that supports the design process by using standards for requirements. A rigid building system based on well defined design tasks together with a technical platform, both for spaces and physical elements, work as a backbone for development of ICT support systems. Product Life Cycle Support (PLCS), as a standard that enables flexibility in categorisation of information through the construction design.
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| 8. |
- Allard, Ingrid
(författare)
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Achieving building energy performance : requirements and evaluation methods for residential buildings in Sweden, Norway, and Finland
- 2015
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Building energy performance has always been important in the cold climate of Sweden, Norway and Finland. To meet the goal that all new buildings should be nearly zero-energy buildings by 2020, set in the EU directive 2010/31/EU [1] on the energy performance of buildings (EPBD recast), the building sector in Europe now faces a transition towards buildings with improved energy performance. In such a transition, a discussion is needed about the objective of the improvement – why, or to what end, the building energy performance should be improved. The objective of improving building energy performance is often a political decision, but scientific research can contribute with knowledge on how the objectives can be achieved.This thesis addresses how the indicators used in the requirements used to achieve building energy performance in Sweden, Norway, and Finland, and the methods used to evaluate these requirements, reflect building energy performance. It also addresses difficulties in achieving comparable and verifiable indicators in evaluations of building energy performance. The research objective has two parts: to review, compare, and discuss (i) requirements and (ii) evaluation methods used to achieve energy performance of residential buildings in Sweden, Norway and Finland. The work in this thesis includes reviews of the requirements used in national building codes and passive house criteria to achieve building energy performance, of methods used to evaluate compliance with such requirements, and of methods used specifically to evaluate the indicator Envelope Air Tightness. The results show that different sets of indicators are used to achieve building energy performance in the studied building codes and passive house criteria. The methods used to evaluate compliance with requirements used to achieve building energy performance are also different, but calculation methods are generally more often used than measurement methods. The calculation- and measurement methods used are often simple. A methodology to analyze the deviation between predictions- and measurements of building energy performance (the performance gap) was developed, to investigate the effects of different evaluation methods on different indicators used to achieve building energy performance. The methodology was tested in a case-study. This study indicated that the choice of method affects which parts of the performance gap reflected in the indicators Supplied Energy (see Terminology), Net Energy (see Terminology), and Overall U-value. Among the reviewed methods to evaluate air tightness, the Fan/Blower Door Pressurization is well known and preferred by professionals in the field. The results in this thesis may be useful when choosing indicators and evaluation methods to achieve different objectives of improving building energy performance and in the quest towards comparable and verifiable indicators used to achieve building energy performance.
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