This thesis is written in collaboration with Total Betong AS, a turnkey contractor in Norway,
who has a vision to build better underground parking spaces under apartment buildings at a
lower cost. It is also a governmental goal as the need for parking spaces under new apartment
buildings is constantly increasing and the value of a parking space is quite significant ranging
from NOK 200 000 - NOK 700 000 (Marschhäuser, 2020). The challenge at hand is to obtain
an additional parking space by selecting a building method that ensures efficient space
utilization while adhering to schedule and budget constraints.
There are several construction methods when building a concrete structure, but in this study,
we focus on cast-in-place concrete, prefabricated concrete, and a combination of both. Castin-place concrete involves creating formwork shapes with reinforcement and subsequently
filling them with fresh concrete on-site. On the other hand, prefabricated concrete refers to
elements produced in a factory under controlled conditions. These elements are then
transported to the construction site for Just-in-Time delivery and installation.
In addition to the quantitative factors of time and cost, there are various qualitative factors
that influence the choice of building method. Hence, it has been useful to use an analysis
method that combines both qualitative and quantitative factors. The Analytic Hierarchy
Process (AHP) is a multicriteria decision-making process that attempts to select a building
method based on input from experienced stakeholders with relevant knowledge of such
projects. Questionnaires were sent to experts to select critical factors for the choice of
building method, and further assign them a degree of importance in relation to each other.
This way, we also get an objective answer based on subjective opinions.
Research shows that productivity levels are lower in the construction industry than in other
industries, while costs and conflict levels are increasing. For these reasons, interest in Lean
techniques and tools has increased to promote collaboration, communication, creativity, and
risk reduction. This thesis therefore explores how these techniques can identify dependencies
throughout a construction project. Lean tools such as the Last Planner System (LPS) and
Pull-Planning techniques are effective when discussing criteria that determine the choice of
execution methods. This can reveal that some factors are more important than others, which
can immediately rule out a building method.
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The study primarily employs qualitative research methods, including an extensive literature
review and a case study involving three reference projects. Two of the reference projects
have been completed, while the third project is ongoing and has been utilized for the AHP
analysis. The case study incorporates various data sources, such as project documents,
tenders, semi-structured interviews, and site visits, to gather comprehensive information.
From the AHP analysis, it emerges that prefabricated concrete is the preferred choice of the
design team for the latest reference project, Bykronen. HSE, quality, and operational
flexibility dominate the choice of construction method compared to the usual factors such as
cost and time. From the interviews and case studies, it emerges that column-free spans and
large wall and roof elements are desirable as they allow for more parking spaces and better
parking utilization. It is therefore concluded that parking basements are particularly well
suited for construction with prefabricated elements as it has a great potential for
improvements in all construction phases while reducing the indirect costs that can be
significant in traditional construction with casting.
Every decision should be grounded on project-specific considerations; however, valuable
insights and lessons can often be transferred from one project to another
