Chương 5 / 515% của kỳ thi
Planning & Estimating
Before a single board is cut, the general building contractor reads the drawings, prices the work, checks it against code, and lines up the trades in the right order. This chapter covers how to interpret plans and specs, run accurate quantity takeoffs with the core estimating formulas, keep the job code-compliant, and manage the paperwork (RFIs and change orders) that keeps a project from unraveling.
Plans, Specs & Shop Drawings
A complete construction document set includes drawings (what and where), specifications (quality and materials), and shop drawings (the fabricator's detailed version of a component). When these disagree, there is an order of precedence, and the contractor must resolve conflicts by asking, not guessing. Reading a scaled drawing correctly and understanding its symbols is the foundation of every estimate.
Order of precedence
When documents conflict, specifications generally govern over drawings, larger-scale details govern over smaller-scale, and written (figured) dimensions govern over scaled measurements.
Standard contract convention (e.g., AIA A201)Never scale for critical dimensions
Use the written dimensions on the plans; printing and copying distort scale, so a ruler on the sheet is only an approximation.
Industry standardShop drawings are submittals, not design
Shop drawings show how a sub will build a component and must be reviewed and approved before fabrication, but reviewing them does not transfer design responsibility to the reviewer.
Standard contract convention (AIA A201)Read the schedules
Door, window, finish, and equipment schedules on the drawings carry critical sizing and model data that the plan views only reference by mark.
Industry standardCost Estimating & Takeoffs
An estimate is only as good as the takeoff behind it. A takeoff is the systematic counting and measuring of every material and labor item from the documents. Convert raw dimensions into purchase units (cubic yards, board feet, squares), then add waste, labor, equipment, overhead, and profit. Memorize the core conversion formulas below, because the exam tests them directly.
Concrete volume in cubic yards
Cubic yards = (length ft x width ft x thickness ft) / 27. Example: a slab 30 ft x 20 ft x 4 in (0.333 ft) = 199.8 cu ft / 27 = 7.4 cu yd; order about 8 cu yd to add roughly 5-10% waste.
Estimating formulaBoard feet of lumber
Board feet = (nominal thickness in x nominal width in x length ft) / 12. Example: a 2 x 10 that is 16 ft long = (2 x 10 x 16) / 12 = 26.7 board feet.
Estimating formulaRoofing squares
One roofing square = 100 square feet of roof area. Squares = total roof area (sq ft) / 100. Example: a 2,400 sq ft roof = 24 squares, plus waste for starter, hip, ridge, and valleys.
Estimating formulaDrywall sheet count
Sheets = total wall/ceiling area (sq ft) / area per sheet; a 4 ft x 8 ft sheet covers 32 sq ft. Example: 1,600 sq ft of wall / 32 = 50 sheets before waste.
Estimating formulaAlways add waste and markup
After the net takeoff, add a waste factor (commonly 5-15% by material), then layer labor, equipment, overhead, and profit to reach the bid price.
Estimating practiceScope & Code Compliance
The estimate must price the full scope shown and implied, and every line of that scope must comply with the current adopted codes. Missing a permit-triggering item or an accessibility requirement can wipe out the profit on a job. Before bidding, the contractor confirms which codes and local amendments govern and whether the design has already accounted for them.
Identify the governing code edition
California enforces the current Title 24 family (Building, Residential, Energy, CALGreen, and more) plus any stricter local amendments; confirm the edition in effect at permit issuance.
2025 California Building Standards Code (Title 24)Permits before covering work
Structural, electrical, plumbing, and mechanical work generally requires a permit, and inspections must occur before the work is concealed.
2025 CA Residential Code §R105 / §R109Accessibility on applicable projects
Commercial and public-facing projects must meet CBC Chapter 11B accessibility requirements; pricing must include compliant routes, restrooms, and hardware.
2025 CA Building Code Chapter 11BPrice implied scope
Notes like 'match existing' or 'per code' still cost money; read the general notes and specifications so implied work is not left out of the bid.
Estimating practiceField Inspection
Building department inspections happen at defined stages, and work covered before its inspection may have to be opened back up at the contractor's expense. Beyond the official inspections, the contractor runs continuous quality control so defects are caught while they are still cheap to fix. Knowing the inspection sequence lets you schedule the trades so nobody waits on an inspector.
Inspect before concealment
Foundation/rebar, rough framing, rough electrical, plumbing, and mechanical must pass inspection before insulation, drywall, or backfill hides them.
2025 CA Residential Code §R109Required inspection stages
Typical hold points are footing/foundation, under-slab utilities, rough-in (framing/MEP), insulation, and final; each must be requested and approved in sequence.
2025 CA Residential Code §R109.1Correct then re-inspect
A failed inspection generates a correction notice; the contractor fixes the item and calls for re-inspection rather than proceeding to cover it.
2025 CA Residential Code §R109Keep approved plans on site
The stamped, approved plan set and the permit card must be available on the job for the inspector, with inspection results signed off in order.
2025 CA Residential Code §R106.3.1Project Coordination
Coordination is the art of putting the right trade in the right place at the right time with the materials and information it needs. The general contractor sequences the schedule, protects the critical path, and resolves conflicts between trades before they collide in the field. Good coordination is largely how a general building contractor earns the fee over a set of specialty subs.
Respect the critical path
The critical path is the chain of tasks that sets the shortest possible project duration; a delay on any critical-path task delays the whole job, so protect and monitor it.
Scheduling principle (CPM)Sequence trades logically
Rough-in (framing and MEP) precedes insulation and drywall; wet trades finish and dry before flooring; paint before final trim and fixtures, so no trade damages another's work.
Construction sequencing practiceCoordinate long-lead items early
Items with long fabrication or delivery times (custom windows, cabinets, switchgear) must be submitted and ordered early so they do not stall the critical path.
Project management practiceHold coordination meetings
Regular meetings with subs, owner, and design team surface conflicts (clash between duct and beam, missing dimension) before they become costly field problems.
Project management practiceChange Orders & RFIs
No project runs exactly as drawn. When information is missing or unclear, the contractor issues a Request for Information (RFI); when the scope, price, or schedule changes, that change must be captured in a written change order before the work proceeds. Doing this work by handshake is how contractors lose money and end up in disputes.
RFI to clarify, not to change
An RFI is a written question to the designer or owner to resolve an ambiguity or conflict; it documents the answer but does not by itself authorize extra cost.
Contract administration practiceChange orders in writing first
Any change to scope, price, or time should be approved in a signed written change order before the work is performed, so payment is not left to memory or goodwill.
Contract administration practiceHome improvement change order rules
On California home improvement contracts, changes to the work must be documented in a written change order signed by both parties, consistent with the contract's requirements.
CA Business & Professions Code (contractor law)Track cost and schedule impact
Each change order should state the added or deducted cost and any change to the completion date, and update the contract sum and schedule accordingly.
Contract administration practiceKiểm tra kiến thức của bạn
Câu hỏi luyện tập về Planning & Estimating