Variations in building project

You are running a construction as a Main Contractor or Consultant?

2009-09-03 22:01:08 補充：
The fact is that variation orders are an unwanted, but inevitable, reality of any construction project.
The variations and variation orders can be minimized when the problem is studied collectively as early as possible, since the problems can be identified and beneficial variations can be made.
There are few rules for valuation of variations as follows:
1) Work of similar character in similar conditions, use BQ rate to determine proportionally valued rates (pro-rata rates),
2) Work of dissimilar character or executed under dissimilar conditions, use BQ rate as far as reasonable (pro-rata rates) or make a fair valuation.
3) Work that cannot be properly measured or valued, use dayworks, which is written evidence of time spent and materials used to carry out variation work. The information is recorded on standard dayworks sheets, which are signed by the clerk of works.
Consideration:
When use BQ rate for VO valuation, you shall take account of the particular features of the job in question, e.g. site conditions, access to site, otherwise a fair valuation cannot be made.

As a Consultant (or Architect, the Project Manager)