Kostnadskalkyler i tidigt skede med BIM: Användning av integrerad 5D BIM i byggprocessens tidiga faser
Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
Digital models are used increasingly within the construction process from schematic design to production. However, architects and planners rarely use these building information models (BIM) when producing quantity take-off and cost estimates. Today, early estimates are in most cases based on cost per square meter (kr/m2) from reference projects. Detailed cost estimates are provided only at the projects later phases when most choices and major decisions have been made. These are often based on manually calculated quantities using 2D-drawings, which also decrease the accuracy of the cost estimate.Cost assessment is an important factor for a developer in determining the feasibility of an investment. During the schematic design phase it is important to be able to estimate the cost of different solutions to recognize which decisions have the most impact on the budget, before continuing into the next phase. Changes of decision made early in later phases are generally too expensive to realize.During the design development phase all of the major decisions for the project will be made. Building materials, installations, fixtures and finishes will be selected, making it possible to develop a more detailed cost estimate, based on the selected building parts, with a lower margin of error. However, these cost estimates are generally expensive and time-consuming to perform.This master thesis examines how an integrated 5D BIM-application can be used to estimate a projects costs rather than traditional ways of manual quantity take-off and estimating. A method is also presented how the designer can create detailed estimates from BIM models. This thesis uses a case study in which a real project is designed and developed in 3D CAD. The 3D BIM-model was then imported to a 5D BIM-application for further analysis and cost estimating.A 5D BIM-application links a 3D BIM-model with schedule (time) and costs. However, working with 5D BIM requires disciplined working methods since mistakes are easy to make. Integrated design and estimating effects many actors in the supply chain. Also, one should consider if cost estimating using 5D BIM is feasible in the project before implementing model based working methods supporting integrated design and cost estimation.5D BIM also effects the relationship between designers, planners and estimators. New skills as well as new relationships need to be developed. For an architect this may lead to new working methods and interaction with the client. The architect can also acquire a major role with more responsibility throughout the project. In interviews with developers, architects and engineers, the interest in integrated design and cost estimation is huge. ”I think that getting the cost estimating integrated in the planning phase is a huge benefit since the way we work today is rather ineffective” – Architect. The construction industry has been slow to embrace new methods and processes from the area of computer-aided design and information technology. It is important to remember that cost estimating with BIM does not mean a new profession. It means new tools that will affect existing working methods, where the implementation can be done gradually. However, the client needs to be aware and demand a BIM driven design process so that new and more effective design and cost estimation methods can be implemented.
Place, publisher, year, edition, pages
2012. , 142 p.
Teknik, 3D, 5D, BIM, Kostnadskalkyler, kalkylering, tidigt skede
IdentifiersURN: urn:nbn:se:ltu:diva-44157Local ID: 1f4ee4b1-e056-4644-a1ce-9a786493a072OAI: oai:DiVA.org:ltu-44157DiVA: diva2:1017432
Subject / course
Student thesis, at least 30 credits
Architectural Engineering, master's level
Validerat; 20120411 (anonymous)2016-10-042016-10-04Bibliographically approved