Lecture 10. Cost Estimating II Flashcards
What are the types of construction estimates?
- Degree of project definition.
- End usage of estimate
- Estimate generating methodology
What is the conceptual estimate?
Average cost per standard unit. (# of beds in hotel, cars in car park, students in uni) (i dont get it?)
What are examples of cost indices?
- General building (commercial buildings, offices, stores etc)
- Manufacturing (assembly, electronic assembly etc)
- Power (thermal and hydroelectric power plants, waste-to-energy plants etc)
Steps for producing as estimate?
1) Identification work gc and subs
2) Study specs gc, read specs subs
3) Affect general conditions on project
4) visit site with pm
5) Team meeting, discuss quantities take-off and pricing
6) RFT subs
7) Think jobsite and general overheads and margins.
What are the errors during detail estimating process?
- Do not cover up/attempt to recover the missing cost with fake change orders.
(trying to recover estimating mistakes could lead to costly project disputes/loss of rep/loss of clients.
What happens at 30 to 40% of the finished design?
- Project team reviews the design. (critical designs would have been made)
- Foundation for producing the first engineering estimate based on drawings.
What happens at 60% finished design?
- Foundation for second engineering estimate.
- Verify proposed system/subsystems meet project needs.
- Compare original proposed budget with more precise quantities and quality requirements.
- ID unresolved problems that will influence final building cost
- Review drawings and specifications. (especially in DB contract)
What happens at 90% finished design?
- Complete set of bid docos
- Last chance review
- Set of docos sent to the permitting authorities for review
What does price include?
- Permanent and temporary materials to be procured.
- Labour required for installing
- Equipment required for moving and installing
- Other consumables such as fuel and tools.
How much of constructing is labour?
30 to 50 percent.
What is the total cost of labour?
Sum of total work hours x wage rate
What are the total work hours?
Sum of quantity of work / productivity rate
What is one of the most inaccurate aspect of estimating?
Productivity rate as it varies day to day, project to project.
What are the factor of productivity rate?
- External factors (market/environment conditions)
- Internal factors (work/management conditions)
What is a contingency?
Amount of money added to an estimate to cover unforseen needs of the project, construction difficulties or estimating accuracy.
