cwicr-takeoff-helper
skillAssist with quantity takeoff using CWICR data. Calculate quantities from dimensions, apply waste factors, and suggest related work items.
apm::install
apm install @datadrivenconstruction/cwicr-takeoff-helperapm::skill.md
---
name: "cwicr-takeoff-helper"
description: "Assist with quantity takeoff using CWICR data. Calculate quantities from dimensions, apply waste factors, and suggest related work items."
homepage: "https://datadrivenconstruction.io"
metadata: {"openclaw": {"emoji": "🗄️", "os": ["darwin", "linux", "win32"], "homepage": "https://datadrivenconstruction.io", "requires": {"bins": ["python3"]}}}
---
# CWICR Takeoff Helper
## Business Case
### Problem Statement
Quantity takeoff requires:
- Accurate calculations from dimensions
- Correct unit conversions
- Waste factor application
- Complete scope coverage
### Solution
Assist takeoff process with CWICR-based calculations, automatic waste factors, unit conversions, and related item suggestions.
### Business Value
- **Accuracy** - Validated calculations
- **Completeness** - Related items suggested
- **Speed** - Quick quantity calculations
- **Consistency** - Standard approaches
## Technical Implementation
```python
import pandas as pd
import numpy as np
from typing import Dict, Any, List, Optional, Tuple
from dataclasses import dataclass
from enum import Enum
import math
class TakeoffType(Enum):
"""Types of takeoff calculations."""
LINEAR = "linear" # Length
AREA = "area" # Square measure
VOLUME = "volume" # Cubic measure
COUNT = "count" # Each/number
WEIGHT = "weight" # By weight
class UnitSystem(Enum):
"""Unit systems."""
METRIC = "metric"
IMPERIAL = "imperial"
@dataclass
class TakeoffItem:
"""Single takeoff item."""
work_item_code: str
description: str
takeoff_type: TakeoffType
gross_quantity: float
waste_factor: float
net_quantity: float
unit: str
dimensions: Dict[str, float]
calculation: str
@dataclass
class TakeoffResult:
"""Complete takeoff result."""
items: List[TakeoffItem]
total_items: int
related_suggestions: List[str]
# Unit conversion factors
CONVERSIONS = {
# Length
('m', 'ft'): 3.28084,
('ft', 'm'): 0.3048,
('m', 'in'): 39.3701,
('in', 'm'): 0.0254,
# Area
('m2', 'sf'): 10.7639,
('sf', 'm2'): 0.0929,
# Volume
('m3', 'cf'): 35.3147,
('cf', 'm3'): 0.0283,
('m3', 'cy'): 1.30795,
('cy', 'm3'): 0.7646,
# Weight
('kg', 'lb'): 2.20462,
('lb', 'kg'): 0.453592,
('ton', 'kg'): 1000,
('kg', 'ton'): 0.001
}
# Standard waste factors
WASTE_FACTORS = {
'concrete': 0.05,
'rebar': 0.08,
'formwork': 0.10,
'brick': 0.10,
'block': 0.08,
'drywall': 0.12,
'tile': 0.15,
'lumber': 0.12,
'roofing': 0.10,
'paint': 0.10,
'pipe': 0.05,
'wire': 0.05,
'duct': 0.08,
'default': 0.05
}
# Related work items by category
RELATED_ITEMS = {
'concrete': ['formwork', 'rebar', 'curing', 'finishing'],
'masonry': ['mortar', 'reinforcement', 'ties', 'lintels'],
'drywall': ['framing', 'insulation', 'taping', 'painting'],
'roofing': ['underlayment', 'flashing', 'ventilation', 'insulation'],
'flooring': ['underlayment', 'adhesive', 'trim', 'transitions']
}
class CWICRTakeoffHelper:
"""Assist with quantity takeoff using CWICR data."""
def __init__(self, cwicr_data: pd.DataFrame = None):
self.cwicr = cwicr_data
if cwicr_data is not None:
self._index_cwicr()
def _index_cwicr(self):
"""Index CWICR data."""
if 'work_item_code' in self.cwicr.columns:
self._cwicr_index = self.cwicr.set_index('work_item_code')
else:
self._cwicr_index = None
def convert_unit(self, value: float, from_unit: str, to_unit: str) -> float:
"""Convert between units."""
if from_unit == to_unit:
return value
key = (from_unit.lower(), to_unit.lower())
if key in CONVERSIONS:
return value * CONVERSIONS[key]
# Try reverse
reverse_key = (to_unit.lower(), from_unit.lower())
if reverse_key in CONVERSIONS:
return value / CONVERSIONS[reverse_key]
return value
def get_waste_factor(self, work_item_code: str) -> float:
"""Get waste factor for work item."""
code_lower = work_item_code.lower()
for material, factor in WASTE_FACTORS.items():
if material in code_lower:
return factor
return WASTE_FACTORS['default']
def calculate_area(self,
length: float,
width: float,
deductions: List[Tuple[float, float]] = None) -> Dict[str, float]:
"""Calculate area with deductions."""
gross_area = length * width
deduction_area = 0
if deductions:
for d_length, d_width in deductions:
deduction_area += d_length * d_width
net_area = gross_area - deduction_area
return {
'gross_area': round(gross_area, 2),
'deductions': round(deduction_area, 2),
'net_area': round(net_area, 2),
'calculation': f"{length} x {width} = {gross_area}, minus {deduction_area} deductions"
}
def calculate_volume(self,
length: float,
width: float,
depth: float) -> Dict[str, float]:
"""Calculate volume."""
volume = length * width * depth
return {
'volume': round(volume, 3),
'calculation': f"{length} x {width} x {depth} = {volume}"
}
def calculate_perimeter(self,
length: float,
width: float) -> Dict[str, float]:
"""Calculate perimeter."""
perimeter = 2 * (length + width)
return {
'perimeter': round(perimeter, 2),
'calculation': f"2 x ({length} + {width}) = {perimeter}"
}
def calculate_concrete(self,
length: float,
width: float,
thickness: float,
work_item_code: str = "CONC-001") -> TakeoffItem:
"""Calculate concrete quantity with related items."""
volume = length * width * thickness
waste = self.get_waste_factor(work_item_code)
net_qty = volume * (1 + waste)
return TakeoffItem(
work_item_code=work_item_code,
description="Concrete",
takeoff_type=TakeoffType.VOLUME,
gross_quantity=round(volume, 3),
waste_factor=waste,
net_quantity=round(net_qty, 3),
unit="m3",
dimensions={'length': length, 'width': width, 'thickness': thickness},
calculation=f"{length}m x {width}m x {thickness}m = {volume:.3f} m3 + {waste:.0%} waste"
)
def calculate_wall_area(self,
perimeter: float,
height: float,
openings: List[Tuple[float, float]] = None,
work_item_code: str = "WALL-001") -> TakeoffItem:
"""Calculate wall area with openings deducted."""
gross_area = perimeter * height
opening_area = 0
if openings:
for w, h in openings:
opening_area += w * h
net_area = gross_area - opening_area
waste = self.get_waste_factor(work_item_code)
order_qty = net_area * (1 + waste)
return TakeoffItem(
work_item_code=work_item_code,
description="Wall finish",
takeoff_type=TakeoffType.AREA,
gross_quantity=round(gross_area, 2),
waste_factor=waste,
net_quantity=round(order_qty, 2),
unit="m2",
dimensions={'perimeter': perimeter, 'height': height, 'openings': len(openings or [])},
calculation=f"{perimeter}m x {height}m = {gross_area:.2f} m2 - {opening_area:.2f} openings + {waste:.0%} waste"
)
def calculate_flooring(self,
length: float,
width: float,
work_item_code: str = "FLOOR-001") -> TakeoffItem:
"""Calculate flooring quantity."""
area = length * width
waste = self.get_waste_factor(work_item_code)
order_qty = area * (1 + waste)
return TakeoffItem(
work_item_code=work_item_code,
description="Flooring",
takeoff_type=TakeoffType.AREA,
gross_quantity=round(area, 2),
waste_factor=waste,
net_quantity=round(order_qty, 2),
unit="m2",
dimensions={'length': length, 'width': width},
calculation=f"{length}m x {width}m = {area:.2f} m2 + {waste:.0%} waste"
)
def calculate_rebar(self,
concrete_volume: float,
kg_per_m3: float = 100,
work_item_code: str = "REBAR-001") -> TakeoffItem:
"""Calculate rebar from concrete volume."""
weight = concrete_volume * kg_per_m3
waste = self.get_waste_factor(work_item_code)
order_qty = weight * (1 + waste)
return TakeoffItem(
work_item_code=work_item_code,
description="Reinforcement",
takeoff_type=TakeoffType.WEIGHT,
gross_quantity=round(weight, 1),
waste_factor=waste,
net_quantity=round(order_qty, 1),
unit="kg",
dimensions={'concrete_m3': concrete_volume, 'kg_per_m3': kg_per_m3},
calculation=f"{concrete_volume} m3 x {kg_per_m3} kg/m3 = {weight:.1f} kg + {waste:.0%} waste"
)
def suggest_related_items(self, work_item_code: str) -> List[str]:
"""Suggest related work items."""
code_lower = work_item_code.lower()
for category, related in RELATED_ITEMS.items():
if category in code_lower:
return related
return []
def room_takeoff(self,
length: float,
width: float,
height: float,
openings: List[Tuple[float, float]] = None) -> TakeoffResult:
"""Complete room takeoff."""
items = []
# Floor
floor = self.calculate_flooring(length, width, "FLOOR-001")
items.append(floor)
# Ceiling (same as floor)
ceiling = TakeoffItem(
work_item_code="CEIL-001",
description="Ceiling",
takeoff_type=TakeoffType.AREA,
gross_quantity=floor.gross_quantity,
waste_factor=floor.waste_factor,
net_quantity=floor.net_quantity,
unit="m2",
dimensions=floor.dimensions,
calculation=f"Same as floor: {floor.gross_quantity} m2"
)
items.append(ceiling)
# Walls
perimeter = 2 * (length + width)
walls = self.calculate_wall_area(perimeter, height, openings, "WALL-001")
items.append(walls)
# Related suggestions
suggestions = ['paint', 'baseboard', 'trim', 'electrical outlets']
return TakeoffResult(
items=items,
total_items=len(items),
related_suggestions=suggestions
)
def export_takeoff(self,
items: List[TakeoffItem],
output_path: str) -> str:
"""Export takeoff to Excel."""
with pd.ExcelWriter(output_path, engine='openpyxl') as writer:
df = pd.DataFrame([
{
'Work Item Code': item.work_item_code,
'Description': item.description,
'Type': item.takeoff_type.value,
'Gross Qty': item.gross_quantity,
'Waste %': f"{item.waste_factor:.0%}",
'Net Qty': item.net_quantity,
'Unit': item.unit,
'Calculation': item.calculation
}
for item in items
])
df.to_excel(writer, sheet_name='Takeoff', index=False)
return output_path
```
## Quick Start
```python
# Initialize helper
helper = CWICRTakeoffHelper()
# Calculate concrete slab
concrete = helper.calculate_concrete(
length=10,
width=8,
thickness=0.2
)
print(f"Gross: {concrete.gross_quantity} m3")
print(f"Order Qty: {concrete.net_quantity} m3")
print(f"Calculation: {concrete.calculation}")
```
## Common Use Cases
### 1. Room Takeoff
```python
room = helper.room_takeoff(
length=5,
width=4,
height=2.8,
openings=[(0.9, 2.1), (1.2, 1.5)] # door, window
)
for item in room.items:
print(f"{item.description}: {item.net_quantity} {item.unit}")
```
### 2. Unit Conversion
```python
meters = helper.convert_unit(100, 'ft', 'm')
print(f"100 ft = {meters:.2f} m")
```
### 3. Rebar from Concrete
```python
concrete = helper.calculate_concrete(10, 8, 0.3)
rebar = helper.calculate_rebar(concrete.gross_quantity, kg_per_m3=120)
print(f"Rebar: {rebar.net_quantity} kg")
```
### 4. Related Items
```python
related = helper.suggest_related_items("CONC-SLAB-001")
print(f"Related: {related}")
```
## Resources
- **GitHub**: [OpenConstructionEstimate-DDC-CWICR](https://github.com/datadrivenconstruction/OpenConstructionEstimate-DDC-CWICR)
- **DDC Book**: Chapter 3.1 - Quantity Takeoff Methods