| name | afrexai-construction-estimator |
| description | Complete construction estimating and cost management system. Use when preparing project estimates, bid proposals, cost breakdowns, value engineering, change order management, or construction budget tracking. Covers residential, commercial, and infrastructure projects. Trigger on 'estimate', 'construction cost', 'bid', 'takeoff', 'cost breakdown', 'change order', 'value engineering', 'construction budget', 'unit pricing', 'RSMeans'. |
Construction Estimator Pro
Complete construction estimating methodology — from quantity takeoff to bid submission. Zero dependencies.
Phase 1: Project Classification & Estimate Type
Estimate Type Decision Matrix
| Project Stage | Estimate Type | Accuracy | Basis | Use Case |
|---|
| Concept | Order of Magnitude | -30% to +50% | SF/unit costs | Go/no-go decisions |
| Schematic | Conceptual/Budget | -15% to +30% | Assembly costs | Budget approval |
| Design Dev | Detailed | -10% to +15% | Quantity takeoff | GMP/bid preparation |
| Construction Docs | Definitive/Bid | -5% to +10% | Full QTO + subs | Lump sum bid |
| Construction | Control | Actual costs | Committed + forecast | Cost management |
Project Brief YAML
project:
name: ""
number: ""
type: residential | commercial | industrial | infrastructure | renovation
delivery: design-bid-build | design-build | CM-at-risk | IPD
location:
city: ""
state: ""
zip: ""
location_factor: 1.00
owner: ""
architect: ""
scope:
gross_sf: 0
stories: 0
site_acres: 0
description: ""
schedule:
bid_date: ""
construction_start: ""
substantial_completion: ""
duration_months: 0
estimate:
type: order-of-magnitude | conceptual | detailed | definitive
base_date: ""
escalation_rate: 0.04
assumptions:
- ""
exclusions:
- ""
allowances:
- item: ""
amount: 0
Project Type Quick Reference
| Type | Key Considerations | Typical $/SF Range (2024-2026) |
|---|
| Single Family Residential | Foundation type, finishes grade, energy code | $150-$400/SF |
| Multi-Family | Unit mix, parking ratio, amenities | $200-$450/SF |
| Office (Class A) | Curtain wall, MEP density, TI allowance | $250-$550/SF |
| Retail | Shell vs TI, storefront, grease traps | $150-$350/SF |
| Healthcare/Hospital | Life safety, med gas, shielding | $400-$900/SF |
| K-12 Education | Prevailing wage, hazmat, phasing | $300-$600/SF |
| Warehouse/Distribution | Clear height, slab flatness, dock count | $80-$180/SF |
| Hotel | Star rating drives finish, FF&E budget | $200-$500/SF |
| Infrastructure (road/mile) | Soil conditions, utilities, traffic control | $2M-$10M/mile |
Phase 2: Quantity Takeoff (QTO)
CSI MasterFormat Division Structure
Use CSI MasterFormat 2018 for ALL estimates. Every line item maps to a division.
| Division | Name | Typical % of Total |
|---|
| 01 | General Requirements | 8-12% |
| 02 | Existing Conditions | 1-5% |
| 03 | Concrete | 8-15% |
| 04 | Masonry | 2-6% |
| 05 | Metals (Structural Steel) | 8-15% |
| 06 | Wood, Plastics, Composites | 3-8% |
| 07 | Thermal & Moisture Protection | 4-8% |
| 08 | Openings (Doors/Windows) | 3-7% |
| 09 | Finishes | 8-15% |
| 10 | Specialties | 1-3% |
| 11 | Equipment | 1-5% |
| 12 | Furnishings | 1-5% |
| 13 | Special Construction | 0-3% |
| 14 | Conveying Equipment (Elevators) | 1-4% |
| 21 | Fire Suppression | 2-4% |
| 22 | Plumbing | 4-8% |
| 23 | HVAC | 8-15% |
| 26 | Electrical | 8-15% |
| 27 | Communications | 1-3% |
| 28 | Electronic Safety & Security | 1-3% |
| 31 | Earthwork | 3-8% |
| 32 | Exterior Improvements | 2-6% |
| 33 | Utilities | 2-5% |
QTO Best Practices
- Measure twice, price once — QTO errors cascade through the entire estimate
- Use consistent units — SF for areas, LF for linear, CY for volume, EA for items
- Add waste factors by material:
- Concrete: 5-8%
- Masonry: 3-5%
- Drywall: 10-12%
- Roofing: 8-10%
- Flooring (tile): 10-15%
- Lumber: 8-10%
- Rebar: 5-7%
- Paint: 10-15%
- Document measurement methodology — so anyone can verify
- Cross-check totals — SF of drywall ≈ 2.5-3x floor area (both sides of walls + ceilings)
QTO Line Item Template
line_item:
division: "03"
spec_section: "03 30 00"
description: "Cast-in-Place Concrete - Elevated Slabs"
quantity: 450
unit: CY
unit_cost:
labor: 85.00
material: 165.00
equipment: 25.00
subcontractor: 0.00
total_unit_cost: 275.00
extended_cost: 123750.00
waste_factor: 0.07
adjusted_quantity: 481.5
notes: "4500 PSI, #5 rebar @ 12\" OC EW, 6\" slab"
source: "Sub quote - ABC Concrete (02/15/2026)"
confidence: high | medium | low
Quantity Verification Cross-Checks
| Check | Formula | Flag If |
|---|
| Concrete per SF | Total CY ÷ Building SF | >0.15 CY/SF (unless heavy structure) |
| Steel per SF | Total tons ÷ Building SF | >15 PSF (unless high-rise) |
| Drywall SF | Total drywall SF ÷ Floor SF | <2.0 or >4.0 ratio |
| Electrical per SF | Electrical $ ÷ Building SF | >$35/SF (standard office) |
| Plumbing fixtures | Count vs occupancy | Missing fixtures for code compliance |
| Parking spaces | Per local code requirements | Below minimum ratio |
Phase 3: Pricing & Cost Assembly
Unit Cost Development
Cost source hierarchy (most reliable first):
- Subcontractor quotes (3 minimum per trade) — best for bid estimates
- Historical project data — adjusted for location, time, scope
- RSMeans/Gordian data — industry standard reference
- Vendor quotes — for specific materials/equipment
- Published cost guides — Marshall & Swift, Craftsman
Labor Cost Build-Up
labor_rate_build_up:
trade: "Carpenter"
base_wage: 42.50
fringe_benefits: 18.75
payroll_taxes: 8.90
total_burden: 27.65
burdened_rate: 70.15
productivity_factors:
weather: 1.00
overtime: 1.00
height: 1.00
congestion: 1.00
shift: 1.00
adjusted_rate: 70.15
Subcontractor Quote Evaluation
Score each sub quote (use minimum 3 per trade):
| Factor | Weight | 1-5 Score |
|---|
| Price competitiveness | 30% | |
| Scope completeness (covers all spec sections?) | 25% | |
| Qualifications/exclusions (red flags?) | 20% | |
| Past performance/reputation | 15% | |
| Bond capacity/insurance | 10% | |
| Weighted Total | 100% | |
Red flags in sub quotes:
- "As needed" or "TBD" line items (scope gap)
- Short validity period (<30 days)
- Unusual exclusions (e.g., electrician excluding wire)
- No reference to spec sections
- Price significantly below others (they missed something)
Crew Rate Assembly
Crew Daily Cost = Σ(Workers × Daily Rate) + Equipment Daily Cost
Crew Daily Output = Units per 8-hour day (from labor standards)
Unit Cost = Crew Daily Cost ÷ Crew Daily Output
Example — Concrete Placement Crew:
- 1 Foreman @ $75/hr × 8 = $600
- 4 Laborers @ $55/hr × 8 = $1,760
- 1 Vibrator operator @ $60/hr × 8 = $480
- Concrete pump (daily rental) = $1,200
- Crew Daily Cost = $4,040
- Daily output: 50 CY
- Unit Labor+Equipment Cost = $80.80/CY
- Material (concrete delivered) = $165/CY
- Total in-place cost = $245.80/CY
Phase 4: Indirect Costs & Markups
General Conditions (Division 01) Checklist
| Item | Duration-Based? | Typical Range |
|---|
| Project Manager | Yes | $12K-$18K/month |
| Superintendent | Yes | $10K-$16K/month |
| Project Engineer | Yes | $8K-$12K/month |
| Field Office (trailer) | Yes | $1K-$3K/month |
| Temporary utilities | Yes | $2K-$5K/month |
| Temporary toilets | Yes | $200-$500/month each |
| Dumpsters/waste removal | Yes | $1K-$4K/month |
| Safety equipment/supplies | Yes | $500-$2K/month |
| Small tools & consumables | Lump | 1-2% of labor |
| Final cleaning | Lump | $0.15-$0.50/SF |
| Permits (building) | Lump | Varies by jurisdiction |
| Insurance (Builder's Risk) | Lump | 0.5-1.5% of cost |
| Performance/Payment Bond | Lump | 1-3% of contract |
| Testing & inspection | Lump | 0.5-1.5% of cost |
| As-built documentation | Lump | $5K-$25K |
| Commissioning support | Lump | $10K-$50K |
Rule of thumb: General conditions = 8-15% of direct costs (lower for large projects, higher for small/complex).
Markup Stack
markup_calculation:
direct_costs: 2500000
general_conditions:
percentage: 0.10
amount: 250000
subtotal_1: 2750000
overhead:
percentage: 0.05
amount: 137500
subtotal_2: 2887500
profit:
percentage: 0.05
amount: 144375
subtotal_3: 3031875
contingency:
design_contingency: 0.05
construction_contingency: 0.03
amount: 242550
bond:
percentage: 0.015
amount: 49118
escalation:
rate: 0.04
months_to_midpoint: 8
amount: 88536
total_estimate: 3412079
cost_per_sf: 341.21
Contingency Guide
| Estimate Type | Design Contingency | Construction Contingency |
|---|
| Order of Magnitude | 15-25% | 10-15% |
| Conceptual | 10-15% | 5-10% |
| Detailed | 3-8% | 3-5% |
| Definitive/Bid | 0-3% | 2-3% |
Contingency is NOT profit padding. Track and justify every contingency draw.
Phase 5: Bid Preparation & Strategy
Bid/No-Bid Decision Scorecard
Score 1-5 for each (minimum 30 to bid):
| Factor | Weight | Score |
|---|
| Project type experience | 3x | |
| Client relationship/history | 2x | |
| Current workload capacity | 3x | |
| Geographic fit | 2x | |
| Profit potential | 3x | |
| Competition level (fewer = better) | 2x | |
| Risk profile (lower = better) | 3x | |
| Schedule feasibility | 2x | |
| Bonding capacity available | 2x | |
| Weighted Total | /110 | |
Bid Day Checklist
48 hours before:
Day of bid:
Competitive Bid Strategy
Market conditions affect markup:
- Hot market (lots of work): Markup 8-12% (O&P combined)
- Normal market: Markup 6-10%
- Slow market: Markup 3-6%
- Must-win/strategic: Markup 2-4% (minimum to cover overhead)
Bid spread analysis (track your results):
Bid Spread = (Your Bid - Low Bid) ÷ Low Bid × 100
- Consistently >10% high → Your costs are inflated or productivity assumptions too conservative
- Consistently <2% from low → You might be leaving money on the table
- Target: Within 3-5% of winning bid
Phase 6: Value Engineering (VE)
VE Opportunity Matrix
| System | VE Opportunity | Typical Savings | Risk Level |
|---|
| Structural | Steel vs concrete frame | 5-15% of structure | Medium |
| Foundations | Spread vs mat vs piles | 10-30% of foundation | High (geotech dependent) |
| Envelope | Curtain wall vs storefront | 15-30% of facade | Low-Medium |
| Roofing | TPO vs modified bitumen | 10-20% of roofing | Low |
| Mechanical | VAV vs VRF | 10-25% of HVAC | Medium |
| Electrical | LED fixtures, panel optimization | 5-15% of electrical | Low |
| Finishes | Material substitutions | 10-40% of finishes | Low |
| Site | Reduce import/export of soil | 10-30% of sitework | Medium |
VE Proposal Template
ve_item:
number: VE-001
description: "Substitute VRF system for conventional VAV"
division: "23"
original:
description: "VAV air handling system with ductwork"
cost: 850000
proposed:
description: "Variable Refrigerant Flow (VRF) with DOAS"
cost: 680000
savings: 170000
savings_pct: 20%
impact:
schedule: "Reduces mechanical rough-in by 2 weeks"
quality: "Better zone control, lower operating cost"
maintenance: "Higher per-unit cost but less ductwork"
code_compliance: "Meets ASHRAE 90.1, verify local amendments"
risk: medium
recommendation: accept | reject | modify
requires_redesign: yes | no
redesign_cost: 15000
net_savings: 155000
VE Decision Rules
- Never VE life safety — fire protection, structural integrity, egress
- Calculate lifecycle cost — cheap upfront ≠ cheap over 20 years
- Get architect/engineer sign-off before bidding VE alternates
- Document everything — VE that isn't documented becomes a scope gap
- Owner decides — present options with data, let them choose
Phase 7: Change Order Management
Change Order Pricing Rules
Contractor markup on changes (typical):
| Tier | Self-Performed Work | Subcontractor Work |
|---|
| Overhead | 10% | 5% |
| Profit | 10% | 5% |
| Bond | Add actual % | Add actual % |
Time & Material (T&M) documentation requirements:
- Daily time sheets signed by owner's rep
- Material invoices with delivery tickets
- Equipment logs with hours
- Photos of work in progress
Change Order YAML Template
change_order:
number: CO-001
date: ""
description: ""
reason:
type: owner-directed | unforeseen-condition | design-error | code-change | scope-clarification
rfi_number: ""
cost_breakdown:
labor:
hours: 0
rate: 0
total: 0
material:
items: []
total: 0
equipment:
items: []
total: 0
subcontractor:
items: []
total: 0
direct_cost: 0
markup: 0.15
total_cost: 0
schedule_impact:
days: 0
critical_path: yes | no
explanation: ""
status: pending | approved | rejected | negotiating
Change Order Negotiation Tips
- Price it immediately — delay weakens your position
- Submit with backup — labor rates, material quotes, productivity analysis
- Separate time from money — negotiate schedule impact independently
- Track cumulative impact — 20 small changes = major schedule disruption (even if each is "0 days")
- Constructive acceleration — if owner delays approval but expects same completion, document it
- Unit price book — agree on unit prices at contract start for common change types
Phase 8: Cost Control During Construction
Earned Value Management (EVM)
Budget at Completion (BAC) = Total budget
Planned Value (PV) = Budgeted cost of work scheduled
Earned Value (EV) = Budgeted cost of work performed
Actual Cost (AC) = Actual cost of work performed
Schedule Performance Index (SPI) = EV / PV
>1.0 = ahead of schedule
<1.0 = behind schedule
Cost Performance Index (CPI) = EV / AC
>1.0 = under budget
<1.0 = over budget
Estimate at Completion (EAC) = BAC / CPI
Variance at Completion (VAC) = BAC - EAC
Monthly Cost Report Template
cost_report:
project: ""
period: ""
report_date: ""
summary:
original_contract: 0
approved_changes: 0
pending_changes: 0
current_budget: 0
committed_cost: 0
actual_cost_to_date: 0
forecast_to_complete: 0
estimate_at_completion: 0
variance: 0
contingency_remaining: 0
schedule:
percent_complete: 0
spi: 0
cpi: 0
days_ahead_behind: 0
cash_flow:
billed_to_date: 0
collected_to_date: 0
retention_held: 0
risk_items:
- description: ""
potential_cost: 0
probability: high | medium | low
mitigation: ""
Cost Control Red Flags
| Signal | What It Means | Action |
|---|
| CPI < 0.95 in first 25% | Systemic cost overrun | Root cause analysis NOW |
| Contingency burn > schedule % | Burning contingency too fast | Tighten change management |
| >5 pending COs unsigned | Cash flow risk, scope dispute | Escalate to PM/owner |
| Sub invoices > committed | Sub performing extra work | Verify scope, issue CO or stop work |
| Retainage release requests early | Sub cash flow problems | Monitor closely, check lien waivers |
Phase 9: Specialty Estimate Types
Renovation/Remodel Estimating
Add these factors to renovation estimates:
- Selective demolition: Price item-by-item (never lump sum)
- Hazmat survey: Asbestos ($3-5K), lead paint ($2-4K) — MANDATORY before bid
- Abatement: 2-5x removal cost vs new construction equivalent
- Protection of existing: Dust barriers, floor protection, HVAC isolation
- Working hours: Occupied buildings = nights/weekends = premium labor
- Discovery allowance: 10-15% for hidden conditions behind walls
- Temporary facilities: HVAC, power, restrooms during renovation
- Phasing/sequencing: Adds 15-30% management overhead
Sitework Estimating
Critical factors:
sitework_checklist:
geotechnical:
- Soil bearing capacity
- Water table depth
- Rock depth (blasting vs mechanical?)
- Contamination (Phase I/II ESA results)
earthwork:
cut_cy: 0
fill_cy: 0
import_export: 0
haul_distance_miles: 0
compaction_required: standard | proctor_95 | proctor_98
utilities:
water_tap_fee: 0
sewer_tap_fee: 0
fire_line: 0
storm_detention: required | not_required
paving:
asphalt_sy: 0
concrete_sy: 0
curb_lf: 0
striping_lf: 0
landscape:
sod_sf: 0
trees_ea: 0
irrigation: yes | no
erosion_control: silt_fence | inlet_protection | retention_pond
MEP (Mechanical/Electrical/Plumbing) Quick Checks
| System | $/SF Benchmark (Commercial Office) | Flag If |
|---|
| HVAC | $25-$50/SF | >$55 or <$20 |
| Plumbing | $12-$25/SF | >$30 or <$8 |
| Fire Protection | $4-$8/SF | >$10 or <$3 |
| Electrical (power) | $18-$35/SF | >$40 or <$12 |
| Low voltage/data | $5-$12/SF | >$15 or <$3 |
| Total MEP | $64-$130/SF | >$150 or <$46 |
Phase 10: Escalation & Location Adjustments
Construction Cost Escalation
Future Cost = Current Cost × (1 + Annual Rate) ^ (Months to Midpoint ÷ 12)
Recent escalation trends (US):
- 2020-2022: 8-15% annually (pandemic/supply chain)
- 2023-2024: 4-6% annually (normalizing)
- 2025-2026 forecast: 3-5% annually
- Long-term average: 3-4% annually
Always escalate to the MIDPOINT of construction, not the start.
Location Factor Application
Local Cost = National Average Cost × City Cost Index
Sample RSMeans City Cost Indices (100 = national average):
| City | Index | | City | Index |
|---|
| New York, NY | 130-145 | | Dallas, TX | 88-95 |
| San Francisco, CA | 125-140 | | Atlanta, GA | 90-97 |
| Boston, MA | 115-130 | | Phoenix, AZ | 88-94 |
| Chicago, IL | 110-120 | | Denver, CO | 95-105 |
| Seattle, WA | 108-118 | | Nashville, TN | 88-95 |
| Washington, DC | 100-110 | | Charlotte, NC | 85-92 |
| Miami, FL | 92-100 | | Houston, TX | 85-93 |
| Minneapolis, MN | 105-112 | | Rural areas | 70-85 |
Phase 11: Estimate Quality Review
100-Point Estimate Quality Rubric
| Dimension | Weight | Criteria |
|---|
| Scope completeness | 20 | All spec sections priced, no gaps, exclusions documented |
| Quantity accuracy | 20 | QTO verified, cross-checks pass, waste factors applied |
| Pricing basis | 15 | 3+ sub quotes per trade, current material prices, documented sources |
| Indirect costs | 10 | GCs detailed (not lump), schedule-based items tied to duration |
| Markup appropriateness | 10 | Market-competitive, risk-adjusted, contingency justified |
| Documentation | 10 | Assumptions listed, basis of estimate narrative, organized by division |
| Adjustments | 10 | Location factor applied, escalation to midpoint, seasonal factors |
| Presentation | 5 | Professional format, clear summary, alternates separated |
Grading: 90+ = Bid-ready | 75-89 = Needs refinement | 60-74 = Major gaps | <60 = Redo
Peer Review Checklist
Phase 12: Common Mistakes & Edge Cases
10 Estimate-Killing Mistakes
| # | Mistake | Prevention |
|---|
| 1 | Missing addenda | Checklist: log every addendum, initial when incorporated |
| 2 | Incomplete sub scope | Write scope sheets with inclusions AND exclusions |
| 3 | Wrong labor rates | Verify union vs open shop, prevailing wage, location |
| 4 | No escalation | ALWAYS escalate to construction midpoint |
| 5 | Lump sum general conditions | Detail every line item tied to schedule |
| 6 | Ignoring phasing | Multi-phase = mobilize/demobilize multiple times |
| 7 | Missing temporary work | Shoring, dewatering, winter protection, dust control |
| 8 | Under-priced site conditions | Get geotech report BEFORE estimating foundations |
| 9 | Scope gaps between trades | Who installs the backing for the TV mount? |
| 10 | Not reading the fine print | Liquidated damages, retainage, payment terms |
Edge Cases
Occupied building renovation:
- Work hours restriction → labor premium 15-40%
- Dust/noise control → add $2-5/SF
- Security/escort requirements → add supervision cost
- Existing condition discovery → 10-15% allowance minimum
Remote/rural project:
- Travel/per diem for crews → $150-$250/worker/day
- Material delivery premium → 5-15% depending on distance
- Limited sub market → fewer quotes, less competitive pricing
- Equipment mobilization → long haul costs for cranes, excavators
Fast-track schedule:
- Overtime premium → plan 20-30% labor cost increase
- Acceleration costs → additional supervision, equipment
- Out-of-sequence work → productivity losses 10-25%
- Premium material delivery → expediting fees
Public/government work:
- Prevailing wages → 20-40% labor cost increase
- DBE/MBE/WBE goals → subcontracting requirements, good faith effort
- Buy American/Buy America → material cost premium 10-30%
- Bid protest risk → ensure perfect compliance with ITB
Design-Build:
- Design contingency higher (incomplete docs at pricing)
- Self-perform vs sub trade-offs
- Design liability insurance (professional liability)
- Allowances for owner decisions not yet made
Natural Language Commands
| Command | Action |
|---|
| "Estimate this project" | Run full estimate workflow from Phase 1 |
| "Price [division/trade]" | Develop unit costs for specific trade |
| "Check my quantities" | Run QTO verification cross-checks |
| "Value engineer [system]" | Generate VE alternatives with savings |
| "Write change order for [scope]" | Generate CO with pricing and backup |
| "Compare sub quotes for [trade]" | Score and compare subcontractor bids |
| "Monthly cost report" | Generate EVM-based cost report |
| "Bid/no-bid analysis for [project]" | Run decision scorecard |
| "Location adjust to [city]" | Apply RSMeans location factor |
| "Escalate costs to [date]" | Calculate escalation to future midpoint |
| "Review my estimate" | Run 100-point quality rubric |
| "Generate bid summary" | Format estimate for bid submission |
