afrexai-construction-estimator

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.

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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  # RSMeans city cost index / national average
  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: ""  # Date costs are based on
  escalation_rate: 0.04  # Annual construction cost escalation
  
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

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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

1. Measure twice, price once — QTO errors cascade through the entire estimate
2. Use consistent units — SF for areas, LF for linear, CY for volume, EA for items
3. 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%
4. Document measurement methodology — so anyone can verify
5. 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

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Phase 3: Pricing & Cost Assembly

Unit Cost Development

Cost source hierarchy (most reliable first):

1. Subcontractor quotes (3 minimum per trade) — best for bid estimates
2. Historical project data — adjusted for location, time, scope
3. RSMeans/Gordian data — industry standard reference
4. Vendor quotes — for specific materials/equipment
5. Published cost guides — Marshall & Swift, Craftsman

Labor Cost Build-Up

labor_rate_build_up:
  trade: "Carpenter"
  base_wage: 42.50
  fringe_benefits: 18.75   # Health, pension, vacation, training
  payroll_taxes: 8.90      # FICA, FUTA, SUTA, workers comp
  total_burden: 27.65
  burdened_rate: 70.15
  
  productivity_factors:
    weather: 1.00           # 1.0 = normal, 1.15 = winter
    overtime: 1.00          # 1.0 = straight time, 1.5 = OT
    height: 1.00            # 1.0 = ground, 1.10 = >30ft
    congestion: 1.00        # 1.0 = open, 1.15 = tight
    shift: 1.00             # 1.0 = day, 1.10 = swing, 1.15 = night
  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

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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     # Home office overhead
    amount: 137500
    
  subtotal_2: 2887500
  
  profit:
    percentage: 0.05     # Varies by market/risk
    amount: 144375
    
  subtotal_3: 3031875
  
  contingency:
    design_contingency: 0.05    # For incomplete drawings
    construction_contingency: 0.03  # For unforeseen conditions
    amount: 242550
    
  bond:
    percentage: 0.015
    amount: 49118
    
  escalation:
    rate: 0.04           # Annual
    months_to_midpoint: 8
    amount: 88536
    
  total_estimate: 3412079
  cost_per_sf: 341.21    # For 10,000 SF building

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.

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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:

• All sub quotes received (minimum 3 per trade)
• All material quotes current (check expiration dates)
• Addenda reviewed and incorporated (ALL of them)
• Scope gaps identified and plugged
• Math verified (independent check)

Day of bid:

• Final sub quotes plugged in
• Markup/profit decision finalized
• Alternates priced if required
• Unit prices calculated if required
• Bid bond secured
• Bid form completed correctly (every blank filled)
• Acknowledge ALL addenda on bid form
• Authorized signature
• Delivered before deadline (allow 1+ hour buffer)

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

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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

1. Never VE life safety — fire protection, structural integrity, egress
2. Calculate lifecycle cost — cheap upfront ≠ cheap over 20 years
3. Get architect/engineer sign-off before bidding VE alternates
4. Document everything — VE that isn't documented becomes a scope gap
5. Owner decides — present options with data, let them choose

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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

1. Price it immediately — delay weakens your position
2. Submit with backup — labor rates, material quotes, productivity analysis
3. Separate time from money — negotiate schedule impact independently
4. Track cumulative impact — 20 small changes = major schedule disruption (even if each is "0 days")
5. Constructive acceleration — if owner delays approval but expects same completion, document it
6. Unit price book — agree on unit prices at contract start for common change types

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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      # Subcontracts + POs
    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

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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    # Net CY to haul
    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

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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

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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

• All addenda acknowledged and incorporated?
• Spec sections cross-referenced to QTO? (no orphan specs)
• Sub quotes match scope of work? (read exclusions!)
• General conditions duration matches schedule?
• Bond premium calculated on TOTAL including markups?
• Sales tax applied correctly? (varies by state, some exempt)
• Prevailing wage rates used if required? (Davis-Bacon, state)
• Owner-furnished items excluded from pricing?
• Alternates priced separately and clearly?
• Math checked independently? (not just formula check — spot-check quantities)

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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

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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