| 1. |
- Asphaug, Silje Kathrin, et al.
(författare)
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Moisture Control Strategies of Habitable Basements in Cold Climates
- 2020
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Ingår i: Building and Environment. - : Elsevier BV. - 0360-1323. ; 169
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Tidskriftsartikel (refereegranskat)abstract
- In many countries with a cold climate, basements are used as dwellings. This presents a major challenge concerning moisture safety design. Climate change is expected to increase the risk of moisture-related damage in basements owing to increasing amounts of stormwater, annual precipitation, and annual temperatures. This study examines the primary moisture control strategies for habitable basements in western cold climate countries by identifying the main differences and similarities in national building recommendations for new buildings. Using Norwegian design guides as a baseline, we identified ten key challenges and compared them with four other cold climate countries’ recommendations given by experts in the field of building physics (building science). The results showed that other countries’ recommendations differ from those of Norway in various key challenges. However, similar but varying recommendations pertaining to ground surface slopes, drainage layers, drainage pipes, capillary breaking layers in floors, avoiding thermal bridges, airtightness, and ventilation were noted. The key differences pertained to the exterior damp proofing of walls, use and position of dimpled membranes and vapour barriers, and use of permeable thermal insulation. The outcome is that countries emphasise the ten key challenges differently. Although the recommendations have many similarities, the weighting (or prioritizing) distinguishes the five countries’ moisture control strategies.
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| 2. |
- Bunkholt, Nora Schjoth, et al.
(författare)
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Experimental Study of Thermal Buoyancy in the Cavity of Ventilated Roofs
- 2020
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Ingår i: Buildings. - : MDPI AG. - 2075-5309. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Pitched wooden roofs are ventilated through an air cavity beneath the roofing in order to remove heat and moisture from the roof construction. The ventilation is driven by wind pressure and thermal buoyancy. This paper studies ventilation driven by thermal buoyancy in the air cavity of inclined roofs. The influence of air cavity design and roof inclination on the airflow is investigated. Laboratory measurements were carried out on an inclined full-scale roof model with an air cavity heated on one side in order to simulate solar radiation on a roof surface. Equipment to measure temperature was installed in the roof model, while air velocity in the cavity was determined by smoke tests. Combinations of different roof inclinations, air cavity heights and applied heating power on the air cavity top surface were examined. The study showed that increased air cavity height led to increased airflow and decreased surface temperatures in the air cavity. Increased roof inclination and heating power applied to the roofing also increased the airflow. The investigations imply that thermal buoyancy in the air cavity of pitched roofs could be a relevant driving force for cavity ventilation and important to consider when evaluating the heat and moisture performance of such a construction.
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| 3. |
- Wondimu, Paulos Abebe, et al.
(författare)
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Early contractor involvement in public infrastructure projects
- 2016
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Ingår i: IGLC 2016 - 24th Annual Conference of the International Group for Lean Construction. ; , s. 13-22
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Konferensbidrag (refereegranskat)abstract
- Advocates of lean construction recommend early contractor involvement (ECI) to further reduce waste. Waste reduction and flow, value generation and sustainability can be improved if some of the companies on a project use lean principles and methods. However, if the contractor is organizationally integrated in the early phases, there is a better chance that the product and process designs are consistent with one another. ECI can ensure better value for money by organizationally integrating contractors knowledge to early phases of projects. This paper contributes to the knowledge about how to implement ECI in public projects. In addition to a literature study, a document study as well as fourteen semi-structured in-depth interviews with key informants from eleven Norwegian public bridge projects were carried out. The EU public procurement directive represents a challenge for public owners when they consider ECI in their projects. However, the studied bridge projects have used various approaches to implement ECI without violating the EU directive. Thirteen approaches are identified in this study. The conclusion is that there are several approaches to implement ECI in public projects, though the contractors' contribution varies a lot depending on which approaches that are implemented.
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| 4. |
- Wondimu, Paulos Abebe, et al.
(författare)
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Implementation of Early Contractor Involvement (ECI) in Norwegian Bridge Projects Procurement
- 2017
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Ingår i: PROCEEDINGS OF THE 9TH NORDIC CONFERENCE ON CONSTRUCTION ECONOMICS AND ORGANIZATION. - 9788750211259 ; , s. 525-536
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Konferensbidrag (refereegranskat)abstract
- According to the literature, even if early contractor involvement (ECI) has several advantages, international and national legislation often represent challenges for public owners considering implementing it in their projects. This might be caused by the obligations that public owners being obliged to use competitive and transparent contractor selection procedures based on both price and quality. In addition, they are obliged to treat all tenderers equally. However, fulfilling these obligations is challenging even in the traditional project delivery methods. Thus, it becomes extra challenging when it should happen together with ECI. Hence, the purpose of this paper is to add to the knowledge of abilities and constraints of using such an approach by studying how public owners use ECI approaches. This research was carried out according to a qualitative approach, based on a literature study, a document study and interviews. Fourteen semi-structured in-depth interviews were conducted with key client personnel from eleven case studies selected from Norwegian bridge projects. Various approaches of ECI have been used in the investigated bridge projects without violating public procurement legislation. Among the identified approaches are; direct contact with specialist contractors in the front-end phase of projects, idea competition, announcing the project with optional technical solutions, using a design & construct contract, information meetings with the contractor branch and a front-end partnering process. This study concludes that public owners might have several alternatives in order to implement ECI. However, the contractors' contributions vary a lot depending on which ECI approaches are implemented and at what time they are implemented in a project. Most of the ECI approaches identified in the targeted projects were implemented in the relatively late phases of the projects. Most of the approaches, however, could have been implemented earlier. Therefore, the ultimate potential of the approaches was not realised. This paper can help public owners to understand the full potential of ECI approaches. Likewise, it can help public owners to benefit more when they implement the approaches in the future.
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| 5. |
- Wondimu, Paulos Abebe, et al.
(författare)
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Success factors for early contractor involvement (ECI) in public infrastructure projects
- 2016
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Ingår i: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 96, s. 845-854
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Konferensbidrag (refereegranskat)abstract
- It is widely accepted that contractor involvement in the front end can influence the outcome of the project in a positive way. However, in the traditional project delivery method of construction projects, the design and construction process are separated and sequentially. As a consequence of this, it is difficult to integrate construction knowledge in the front-end of projects. The evolving project methods are designed to remove such typical challenges by involving contractors early in the process. The purpose of this paper is to explore the success factors for early contractor involvement (ECI) in public infrastructure projects. In addition, the paper aims to propose suitable approaches to implement ECI for public owners in future projects without violating the EU public procurement directives. In addition to a literature study, multiple case studies on eleven projects selected from the Norwegian public bridge projects were carried out. The majorly identified ECI success factors are timing of ECI application, proper compensation, trust, contractors' qualification, owners' competence, and risk distribution. The paper concludes that public owners can implement ECI by using various approaches without violating the EU public procurement directive. Furthermore, based on the identified success factors, effective practical strategies for the successful implementation of ECI may be generated. (C) 2016 The Authors.
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