L10: Cost Estimating Flashcards
(75 cards)
What are different types of construction estimates?
- Degree of project definition
- End usage of estimate
- Estimate generating methodology
What are 2 construction estimates for end usage?
- Conceptual for finance
- Detail estimates for lump sum tenering
What are 2 construction estimates for estimate generating methodology?
- Stochastic
- Deterministic
How are conceptual estimates estimated?
Using average costs per standard unit
What are examples of construction cost indices?
- Department of building and housing
- NZTA
- Reserve Bank
- Diesel / steel/..
- Statistics NZ
What are important components to producing an estimate?
- Scan the tender documents
- Review drawings
- Review structural drawings
- Check wall sections
- Check mech/ elec/ fire/ security systems and note interference with construction
- Identification work GC ans sub’s
- Study specs of GC, read spec sub’s
- Affect general conditions on project
- Visit site with PM
- Team meeting and discuss quantities take-off and pricing
- RFT subs
- Think jobsite and general overheads and margins
(additional detail in notes)
What to do if errors in estimating?
Errors may occur during the detail estimating process. If there are errors do not cover up or attempt to revoer the missing cost with fake change orders.
Attempting to recover estimating mistakes with future contractor-initiated project changes could lead to costly project disputes, loss of reputation, or loss of clients.
Activites when 30-40% finished design.
- project team to review the design. (many critical design decisions have already been made)
- foundation for producing the first engineering estimate based on drawings (estimator can develop quantities of work and apply actual unit prices)
Activites when 60% finished design.
- foundation for the second engineering estimate
- Verify proposed systems and subsystems meet project needs
- Compare original proposed budget with more precise quantities and quality requirements
- Identify unresolved problems that will greatly influence the final building cost
- Reviewing the drawings and specifications for construction capabilities by a team of construciton professionals (constructability, especially in a design-build contractual agreement)
Activities when 90% finished design.
- complete set of bid documents
- “last chance review”, the owner should be sure that the goals of the project are totally achieved
- set of documents will be sent to the permitting authorities for their review
What factors affect accuracy?
The quantity and cost of:
- construction materials
- labour
- equipment
Important components of materials.
- quantity
- waste (industrial stds and handling/ installation)
- pricing
Explain pricing.
Assigning a dollar value to a work item based on given specifications and the predetermined quantity required.
What should pricing include?
The cost of each of these subcomponents:
- permanent/ temporary materials
- labour required for installing
- equipment required for moving/ installing
- other consumables (e.g. fuel and tools)
Important components of labour.
- Types of labour
- Monetary factors & productivity
accounts for 30-50% of construction costs
What are the advantages of union membership for workers?
- Hiring hall for job referral
- Apprenticeship training
- Right to strike, wages, job conditions, benefits and job security
- Power to act collectively as a group to enforce demands
- Organisation affiliation
What are the disadvantage of union membership for workers?
- Payment for initiation fees, dues or assessments
- No choice of employer, lack merit promotions
- restrictive work assignment
What are the advantages of union membership for construction companies?
- Available pool of skilled labour from union
- Fixed wages and uniform conditions, prescribed by union
What are the disadvages of union membership for construction companies?
- Restrictive work rule
- Inhibit innovation
- Workers have no loyalty to contractor
- Jurisdictional dispute can affect contractor
What are monetary factors? (relating to money)
- base wage rates
- fringe benefits
- wage premiums
Explain productivity.
Labour productivity rates in the construction industry vary on an individual, daily, and project basis. As a result, the labour cost is one of the most inaccurate aspects of estimating.
What are factors that affect productivity?
External factors
- market conditions
- environmental conditions
Internal factors
- work conditions
- management conditions
Explain the effect of overtime.
Increasing days past 5 days per week, or increasing the amount of hours per day will likely lead to a decrease in production efficiency.
What are important components to consider for equipment.
- specific or general use
- buy, lease or rent
- mobilisation
- operator
- tools