| name | architect-calculator |
| description | Seven Python-based architectural calculators for common design computations: area and density calculations (GFA, NGA, unit count, population, parking), thermal U-value analysis for multi-layer constructions, daylight factor estimation using BRE methodology, egress compliance checking (occupant load, exit width, travel distance), structural gravity load and tributary area calculations, annual energy demand estimation via degree-day method, and construction cost estimation by building type, quality, and region.
|
Architect Calculator
A suite of seven command-line Python calculators for rapid architectural
design computations. Each calculator accepts parameters via command-line
arguments, validates inputs, and produces either human-readable or
JSON-structured output.
All scripts are located in the scripts/ directory and can be run with:
python scripts/<calculator_name>.py [arguments]
Add --json to any command for structured JSON output suitable for
piping into other tools or automation workflows.
1. Area Calculator (area_calculator.py)
Calculates development density metrics from site area and floor area
ratio (FAR), including gross floor area, net usable area, residential
unit count, estimated population, and parking requirement.
Parameters
| Parameter | Flag | Default | Unit | Description |
|---|
| Site Area | --site-area | Required | m2 | Total site/plot area |
| Floor Area Ratio | --far | Required | ratio | Permitted FAR / plot ratio |
| Net-to-Gross Ratio | --ntg-ratio | 0.80 | ratio | NGA as fraction of GFA (0.0-1.0) |
| Avg Unit Size | --avg-unit-size | 85 | m2 | Average residential unit area |
| Persons per Unit | --persons-per-unit | 2.5 | persons | Average household size |
| Parking Ratio | --parking-ratio | 1.0 | spaces | Parking spaces per dwelling unit |
Example
python scripts/area_calculator.py --site-area 5000 --far 2.5 --ntg-ratio 0.82
Sample Output
=== Area & Density Calculator ===
Site Area: 5,000.00 m2
Floor Area Ratio: 2.50
---------------------------------------
Gross Floor Area: 12,500.00 m2
Net-to-Gross Ratio: 0.82
Net Gross Area: 10,250.00 m2
---------------------------------------
Average Unit Size: 85.00 m2
Estimated Units: 120
Persons per Unit: 2.50
Estimated Population: 300
---------------------------------------
Parking Ratio: 1.00 spaces/unit
Parking Spaces: 120
2. U-Value Calculator (uvalue_calculator.py)
Calculates the thermal transmittance (U-value) of a multi-layer wall,
roof, or floor construction by summing thermal resistances of each layer
plus surface resistances.
Parameters
| Parameter | Flag | Default | Unit | Description |
|---|
| Layers | --layers | Required | JSON string | Array of layer objects |
| Rsi Internal | --rsi-internal | 0.13 | m2K/W | Internal surface resistance |
| Rsi External | --rsi-external | 0.04 | m2K/W | External surface resistance |
Each layer object: {"name": "...", "thickness_mm": N, "conductivity": N}
Example
python scripts/uvalue_calculator.py --layers '[
{"name": "Brick", "thickness_mm": 102, "conductivity": 0.77},
{"name": "Cavity air gap", "thickness_mm": 50, "conductivity": 0.18},
{"name": "Mineral wool", "thickness_mm": 100, "conductivity": 0.035},
{"name": "Concrete block", "thickness_mm": 140, "conductivity": 1.13},
{"name": "Plaster", "thickness_mm": 13, "conductivity": 0.16}
]'
Sample Output
=== U-Value Calculator ===
Layer Thickness(mm) Conductivity(W/mK) R-value(m2K/W)
---------------------------------------------------------------------------
Rsi (internal) -- -- 0.1300
Brick 102 0.770 0.1325
Cavity air gap 50 0.180 0.2778
Mineral wool 100 0.035 2.8571
Concrete block 140 1.130 0.1239
Plaster 13 0.160 0.0813
Rse (external) -- -- 0.0400
---------------------------------------------------------------------------
Total R-value: 3.6425 m2K/W
U-value: 0.2745 W/m2K
Passive House target (wall): 0.15 W/m2K -- DOES NOT MEET
Typical code target (wall): 0.30 W/m2K -- MEETS TARGET
3. Daylight Calculator (daylight_calculator.py)
Estimates average daylight factor for a side-lit room using the BRE
simplified formula.
Parameters
| Parameter | Flag | Default | Unit |
|---|
| Room Width | --room-width | Required | m |
| Room Depth | --room-depth | Required | m |
| Room Height | --room-height | Required | m |
| Window Width | --window-width | Required | m |
| Window Height | --window-height | Required | m |
| Window Sill Height | --window-sill-height | Required | m |
| Glazing Transmittance | --glazing-transmittance | 0.65 | ratio |
| Average Reflectance | --average-reflectance | 0.50 | ratio |
Example
python scripts/daylight_calculator.py \
--room-width 4.0 --room-depth 6.0 --room-height 3.0 \
--window-width 2.5 --window-height 1.8 --window-sill-height 0.9
Sample Output
=== Daylight Factor Calculator ===
Room: 4.00m W x 6.00m D x 3.00m H
Window: 2.50m W x 1.80m H (sill at 0.90m)
---------------------------------------
Window Area: 4.50 m2
Total Room Surface Area: 96.00 m2
Window-to-Floor Ratio: 18.75%
Glazing Transmittance: 0.65
Average Reflectance: 0.50
Visible Sky Angle: 60.1 deg
---------------------------------------
Average Daylight Factor: 2.34%
Assessment: ADEQUATE (target >= 2.0% for habitable rooms)
4. Egress Calculator (egress_calculator.py)
Calculates occupant load, required number of exits, minimum exit widths,
and travel distance compliance per IBC.
Parameters
| Parameter | Flag | Default | Description |
|---|
| Floor Area | --floor-area | Required | Net floor area in m2 |
| Occupancy Type | --occupancy-type | Required | IBC occupancy (A-1 to U) |
| Sprinklered | --sprinklered | False | Flag: building is sprinklered |
| Num Stories | --num-stories | 1 | Number of stories |
Example
python scripts/egress_calculator.py --floor-area 800 --occupancy-type B --sprinklered --num-stories 4
Sample Output
=== Egress Calculator ===
Floor Area: 800.00 m2
Occupancy Type: B (Business)
Sprinklered: Yes
Number of Stories: 4
---------------------------------------
Occupant Load Factor: 9.3 m2/person
Occupant Load: 86 persons
---------------------------------------
Required Exits: 2
Min Exit Width (total): 1,376 mm
Width per Exit: 688 mm
Min Door Width: 813 mm (32 inches)
---------------------------------------
Max Travel Distance: 91.0 m (300 ft) [sprinklered]
Max Common Path: 23.0 m (75 ft)
Max Dead End: 15.0 m (50 ft)
COMPLIANCE: Review travel distances on plans.
5. Structural Load Calculator (structural_load_calculator.py)
Calculates tributary area gravity loads for preliminary structural sizing.
Parameters
| Parameter | Flag | Default | Unit | Description |
|---|
| Tributary Area | --tributary-area | Required | m2 | Column tributary area |
| Num Floors | --num-floors | Required | integer | Number of supported floors |
| Dead Load | --dead-load | 4.5 | kN/m2 | Dead load per floor |
| Live Load | --live-load | auto | kN/m2 | Live load (auto per occ.) |
| Occupancy Type | --occupancy-type | office | string | For auto live load selection |
Example
python scripts/structural_load_calculator.py --tributary-area 36 --num-floors 8 --occupancy-type office
Sample Output
=== Structural Load Calculator ===
Tributary Area: 36.00 m2
Number of Floors: 8
---------------------------------------
Dead Load: 4.50 kN/m2 per floor
Live Load: 2.50 kN/m2 per floor (office)
Total per Floor: 7.00 kN/m2
---------------------------------------
Load per Floor: 252.00 kN
Total Column Load: 2,016.00 kN (8 floors)
Factored Load: 2,822.40 kN (1.2D + 1.6L)
---------------------------------------
Preliminary Column: ~400x400 mm RC (fc'=35 MPa)
6. Energy Calculator (energy_calculator.py)
Estimates annual heating and cooling energy demand using the degree-day
method.
Parameters
| Parameter | Flag | Default | Unit | Description |
|---|
| Floor Area | --floor-area | Required | m2 | Conditioned floor area |
| Envelope Area | --envelope-area | Required | m2 | Total envelope area |
| Average U-value | --average-u-value | Required | W/m2K | Area-weighted average U |
| Heating Degree Days | --heating-degree-days | Required | Kd | Annual HDD (base 18C) |
| Cooling Degree Days | --cooling-degree-days | Required | Kd | Annual CDD (base 24C) |
| Ventilation Rate | --ventilation-rate | 0.5 | ACH | Air changes per hour |
| Internal Gains | --internal-gains | 5.0 | W/m2 | Internal heat gains |
Example
python scripts/energy_calculator.py \
--floor-area 500 --envelope-area 800 --average-u-value 0.35 \
--heating-degree-days 3000 --cooling-degree-days 500
Sample Output
=== Energy Calculator ===
Floor Area: 500.00 m2
Envelope Area: 800.00 m2
Average U-value: 0.35 W/m2K
---------------------------------------
Heating Degree Days: 3,000 Kd
Cooling Degree Days: 500 Kd
Ventilation Rate: 0.50 ACH
Internal Gains: 5.00 W/m2
---------------------------------------
Transmission Loss: 6,720.00 kWh/yr
Ventilation Loss: 4,050.00 kWh/yr
Internal Gains: -2,190.00 kWh/yr
Heating Demand: 8,580.00 kWh/yr
---------------------------------------
Cooling Demand: 2,356.00 kWh/yr
---------------------------------------
Total Demand: 10,936.00 kWh/yr
EUI: 21.87 kWh/m2/yr
Passive House target: 15 kWh/m2/yr -- DOES NOT MEET
7. Cost Calculator (cost_calculator.py)
Estimates construction cost based on building type, quality level, and
geographic region.
Parameters
| Parameter | Flag | Default | Description |
|---|
| GFA | --gfa | Required | Gross floor area in m2 |
| Building Type | --building-type | Required | residential/office/retail/hospital/school/hotel |
| Quality | --quality | standard | basic/standard/premium |
| Region | --region | north-america | north-america/europe/middle-east/asia/australia |
| Include External | --include-external | False | Flag: include site works |
Example
python scripts/cost_calculator.py --gfa 5000 --building-type office --quality premium --region europe
Sample Output
=== Construction Cost Calculator ===
Gross Floor Area: 5,000.00 m2
Building Type: Office
Quality Level: Premium
Region: Europe
---------------------------------------
Base Cost Rate: 2,800.00 USD/m2
Construction Cost: 14,000,000 USD
---------------------------------------
Professional Fees (12%): 1,680,000 USD
Contingency (7.5%): 1,050,000 USD
External Works: --
---------------------------------------
Total Development Cost: 16,730,000 USD
Cost per m2 (total): 3,346.00 USD/m2
Methodology Reference
Detailed formulas and methodology for each calculator are documented in
references/calculator-reference.md.
Error Handling
All calculators validate inputs and provide clear error messages:
- Missing required parameters display usage help
- Out-of-range values are rejected with explanatory messages
- Invalid occupancy types list accepted values
- Malformed JSON input shows expected format
Integration
JSON output (--json flag) enables integration with:
- Other scripts in the pipeline
- Spreadsheet tools (parse JSON)
- Web dashboards
- Automated reporting systems
- BIM parameter injection
