Chapter 4+5 Flashcards
What are the five activities in detailed estimates?
- Development of construction methods
- Preparation of the constitution scheduled
- Quantity takeoffs
- Estimation of costs
- Assessment of risk contingency
What WBS stands for?
Work Breakdown Structure
What WBS is used for?
Used to organize tasks for reporting schedules and tracking costs
What are the three essential elements to produce an accurate detailed estimate?
1) Quantity take off - Determines the quantity of work
2) Productivity
3) Unit cost
What if the plans are drawn in metric units and all your pricing information is in English units? (Quantity take-off)
Complete the takeoff using the units of the plans, metric units, and later convert all units to English units for pricing
What is the order of measurement? Depth, length,width
Length X width X height
How many decimal places are used for QTO?
2
How QTO is taken, gross/net in place? explain
Net - quantities are calculated using the sizes and dimensions indicated on the drawings with no adjustments to the values obtained for waste factors and suchlike
QTO What is an assembly?
A component of the work that can be considered separately from the other parts of the work
Consider the perimeter foundation wall as an assembly in the estimate for a house - which items would it include for QTO?
- Forms (sides)
- Forms (openings and blackouts)
- The concrete
- Reinforcing steel
- Rubbed finish on the exposed concrete surface
Why use assemblies in QTO?
Avoiding repetition - Assembly is evaluated only once while the same dimensions are shared by a number of items within the assembly
List the 5 price categories
1) Labour
2) Equipment
3) Materials
4) Subcontracts
5) General expenses
What are the risks for a contractor in a lump-sum contract?
1) Takeoff quantities are too low
2) Productivity does not meet anticipated productivity
3) Subs or Material suppliers fail to meet obligations
What are the two main approaches for pricing labour and equipment?
1) Use of unit prices - applied to listed takeoff quantities
2) Use of productivity rates - |Convert takeoff quantities into labour-hour| then applies wage rates and equipment rates to the total hours to estimate prices.
What are labour and equipment pricing risk factors:
1) Productivity of labour or equipment is difficult to evaluate/anticipate
2) Hourly rate of labour or cost of equipment can fluctuate
What are the 2 groups productivity of equipment & labour are influenced by?
1) Job factors
- Weather conditions
- Access to and around the site
- Distance from materials and equipment sources
2) Labour and management factors
- Quality of job supervision
- Quality of labour
- Experience in similar projects in the past (learning curve)
Is it better to buy or rent equipment?
Buying is justified only when the investment promises NET BENEFITS in compression with renting or investing the cash elsewhere
What do you need to know while calculating depression?
1) Asset’s initial cost (Present value)
2) Useful life
3) Salvage value
4) Depreciation model
What are the 3 depreciation models?
1) Straight-line - Allocated equally per year over the useful life of the asset
2) Declining - balance - Annual depreciation amounts decline as the asset gets older
3) Production or use - Depreciation value in a specific year depends on asset use in that year
