Quality is considered in a reported square foot estimate by using the 1/4, median, and 3/4 costs.

This chapter has reviewed the types of estimates that are prepared in the early stages of a project. The conceptual/ROM estimate is conducted early, is used primarily for budgetary reasons, is done quickly, and provides accuracy in the +- 20 percent range. The square foot estimate is done primarily in the conceptual stage, takes slightly longer than a ROM estimate, and provides accuracy in the +- 15 percent range. The residential square foot, like the commercial estimate, is also done in the conceptual stage of the project, providing accuracy in the +- 15 percent range.
All these estimates can be done with little or no design information. As the number of project design decisions increases, the amount of detail that needs to be quantified and priced increases as well, providing better accuracy, but taking longer to accomplish. This chapter uses information provided primarily by the R.S. Means Company, but most large owners, designers, and construction companies, through historical records, develop their own historical costs that they use for estimates.
The process followed in conducting all the estimates discussed was similar in that each estimate considered the five major elements of size, quality, location, time, and market. In the ROM estimate, the size was considered by units; quality was considered by 1/4, median, and 3/4; location and time were treated by indices; and market would be figured into the contingency. The square foot estimate considered project area, while the remaining items were all treated the same as in the ROM. In the assemblies estimate, which will be discussed in Chapter 6, the size of the project is quantified by assemblies, and quality is considered by selecting the specific system desired; location and time are factored into overhead and profit percentages.
The unit price estimate, the last estimate type to be covered (see chapter 7), works with the smallest items of work . This estimate takes the longest to complete but is the most accurate.

Sets with similar terms

Which conceptual estimating method traditionally has the greatest level of accuracy at +/

Which type of estimate is the most accurate quizlet?

Which style of estimate is more accurate?

How is an assembly estimate completed?