Case Study - Working Drawings- E: Detail Design
General Observations
It is the purpose of this stage to arrive at final decisions on all aspects of the project before proceeding to the next stage: (F Working Drawings: Production Information)
Each element contained in the cost plan has to be cost checked during this stage in order to confirm that the developed design solution is financially viable. Chapter 11 of the textbook describes this process in detail and further comment can be found in Chapter 8 of the textbook.
When all the cost checks have been carried out the cost bracket set during B Briefing: Feasibility stage can be confirmed and value for money achieved due the careful consideration that has been given to the design of each element during the Sketch Plan stage.
The cost check will confirm one of three possibilities:
That the cost target is correct
- That the cost target is too low
- That the cost target is too high.
Any of the latter two scenarios will necessitate remedial action to the proposed element, as discussed in Chapters 8 and 11, if the cost bracket is to retain its validity and the correct elemental distribution is to be maintained. The cost checking should be carried in a sequence which considers the most significant elements, in terms of their influence on other elements, first. The reason for this is that if changes have to be made to these elements then there will inevitably have to be changes made to any subsequent dependent elements.
You are invited to see the authors cost checks for the project by examining our cost model which shows the cost checking process and the resulting cost checked detailed cost plan.
Having carried out the cost checking process we can be reasonably confident that when the tenders are submitted by the selected contractors the lowest bid will equate closely to the cost bracket that was set during B Briefing: Feasibility stage.
Thus by going through the case study you have been able to observe the application of design cost management within a lump sum limited competitive contract based on a complete and final design solution. Remember as explained in the textbook , especially in chapters 3 and 4 there a number of other approaches to carrying out design and construction which attempt to overcome many of the limitations and problems that are inherent within the construction industry. Again you are reminded to study the textbook, especially chapters 3, 4 and 12, where these issues are discussed together with how design cost management can be made more effective in terms of helping to deliver, on behalf of the client, the right building of the right quality in the right time and at the right price.