📋 Overview
The Site Land Area TabPage calculates the gross site land requirements based on the building ground projection area (derived from the Building Area Tab) while strictly applying legal Building Coverage Ratios (BCR). It also simulates the X/Y perimeter dimensions, setback corridors, and yard access paths visually.
🎯 Core Capabilities
- Automatically calculates required site footprint based on selected BCR percentages.
- Optimizes site perimeter X/Y dimensions to match building geometry.
- Sets perimeter access aisle widths (X and Y directions) for truck yards and fire access.
- Visually configures canopy direction and annex building orientations (parallel or perpendicular).
- Automatically computes Floor Area Ratio (FAR) and triggers alerts if FAR exceeds 200%.
- Renders a graphical 2D site layout plan.
🎯 Purpose & Applications
Primary Objectives
🏗️ Zoning Compliance
BCR (30% to 80%) and FAR (100% to 500%) are legally restricted based on industrial zoning laws. This screen adjusts BCR parameters to ensure the planned facility is legally compliant.
📐 Real Estate Site Selection
Calculates the exact minimum plot size and perimeter dimensions required, providing hard criteria for real estate land acquisition or lease negotiations.
🚛 Truck Yard & Parking Layout
Ensures adequate perimeter setbacks for truck turning radii, fire engine access, and staff parking.
🖼️ Layout Visualization
Generates a 2D schematic demonstrating the building's placement within the plot, ideal for executive presentations and architectural briefs.
Practical Use Cases
- Land Acquisition Briefing - Verifying if candidate plots meet BCR/FAR requirements.
- Greenfield Site Sizing - Deriving minimum square meterage for new DC land.
- Brownfield Fit-Check - Checking if a proposed building fits within an existing owned plot.
- Multi-Storey Justification - Reverse-calculating maximum storeys from FAR limits.
- Proposal Generation - Appending site schematics to stakeholder presentations.
🖥️ Interface Architecture
Main Area Layout
| Area Name | Function Summary | Main Controls |
|---|---|---|
| BCR / FAR Setting | Input for legal zoning constraints | BCR ComboBox (30-80%), FAR Display |
| Site Dimension Display | Required site area and X/Y dimensions | Site Area, X-Length, Y-Length TextBoxes |
| Setback Configuration | Perimeter aisle width settings | Passage X, Passage Y TextBoxes |
| Building Placement | Annex and canopy orientation | Annex A/B radio buttons, Canopy toggles |
| Site Layout Graphic | Visual rendering of site vs building | PictureBox (2D Map) |
| Dimension Details | Granular area dimensions | TabControl6 (Aisle, Canopy, Annex details) |
📝 Input Parameter Settings
1. Building Coverage Ratio (BCR) Setting
BCR Dropdown (Cb)
Options: 30%, 40%, 50%, 60%, 70%, 80%
Default: 60%
Sets the legal maximum percentage of land that can be covered by the building footprint.
💡 What is BCR?
BCR = Building Projection Area ÷ Total Site Area × 100
Example: For a 2,000 m² site with 60% BCR → Max building projection is 1,200 m².
⚠️ Typical BCR Zoning Limits (Japan)
- Class-1 Residential: 50–60%
- Quasi-Industrial: 60%
- Industrial: 60%
- Exclusive Industrial: 50–60%
*Actual limits vary based on corner lot allowances and fire zone designations. Always consult local municipal regulations.
2. Manual Site Dimension Adjustment
| Setting | Description | Default Behavior |
|---|---|---|
| Site Depth (Y) | Plot length in the depth direction (m) | Manually adjustable after auto-calc |
| Site Width (X) | Plot length in the width direction (m) | Auto-calculates as (Total Area ÷ Site Depth) |
📏 Dimension Adjustment Workflow
The system initially derives site dimensions matching the building's aspect ratio.
If the user manually alters the Site Depth, the width is automatically recalculated to maintain the required gross site area.
3. Setback / Aisle Width Settings
⚠️ Setback Engineering Standards
- Truck Turning Radius: Minimum 6m clearance required for large trailers.
- Fire Engine Access: Minimum 4m width and 4.5m height clearance required by fire code.
- Emergency Access: Ensure at least one perimeter aisle maintains ≥4m continuous clearance.
4. Annex Building Orientation
🏢 Annex Layout A (Parallel)
Places the annex adjacent to the main building on the X-axis.
Use Case: Ideal for wide, rectangular plots.
🏢 Annex Layout B (Perpendicular)
Places the annex adjacent to the main building on the Y-axis.
Use Case: Ideal for deep, narrow plots.
5. Canopy Specifications (Inherited)
| Setting | Impact |
|---|---|
| Canopy Enabled | Renders distinct canopy zones on the site layout graphic. |
| Integrated Docks | Canopy area becomes zero, and dock space is absorbed inside the main building footprint. |
🔢 Calculation Logic
Basic Calculation Flow
(From Bldg Tab)
BCR
Site Area
Dimensions
1. Required Site Area Calculation
📐 Calculation Example
Parameters:
- Main Projection: 1,200 m²
- Canopy Projection: 130 m²
- Annex Projection: 0 m²
- Total Building Projection: 1,330 m²
- BCR: 60%
Execution:
2. Site X/Y Dimension Sizing
The site aspect ratio inherits the main building's ratio.
Ex: If the building is 3:2, the site will aim for a 3:2 bounding box.
Once site area is known, iterative logic derives the dimensions:
Depth = i × MainDepthRatio
(Find smallest 'i' where Width × Depth ≥ Target Site Area)
📐 Sizing Example (3:2 Ratio, Target Area 2,217 m²)
i=1: 3m × 2m = 6 m² → Too small
i=10: 30m × 20m = 600 m² → Too small
i=27: 81m × 54m = 4,374 m² → Exceeds target ✅
Final Trim: Depth = 2,217 ÷ 81 = 27.4m → Round down to 27m
Final Result: Width 81m × Depth 27m = 2,187 m²
3. Residual Aisle Width Calculation
Residual Aisle Y = Total Site Depth - (Main Bldg Depth + y1 + y2 + Annex Depth + y4)
This calculates remaining unallocated space after defined setbacks and buildings are placed.
4. Floor Area Ratio (FAR) & Alerts
⚠️ FAR > 200% Overload Alert
If the calculated FAR exceeds 200%, a red warning appears on-screen:
"Please reduce FAR below 200% (e.g., lower the BCR to acquire more land)"
Resolution: Lower the BCR to increase site area, or reduce the number of storeys to lower gross floor area.
5. Canopy & Integrated Dock Logic
With Canopy
Canopy depth (default 7m) is tracked via d1, d2 variables.
1-Sided Dock: w1 = Canopy A width, d1 = Canopy A depth
2-Sided Dock: Adds w2, d2 parameters for Canopy B
Integrated Docks
External canopy projection drops to zero. Space is visually represented via "Integrated Dock X/Y" dimensions inside the main perimeter.
🗺️ Site Layout Rendering
Visual Site Map (PictureBox)
The central PictureBox draws a proportional 2D schematic of the site configuration. Elements include:
Outer property lines
Primary structure footprint
Dock overhangs
Standalone office block
Empty yard/aisle space
Line-segment measurements
Layout Pattern Examples
Pattern 1: No Annex + Canopy (1-Sided Dock)
Standard configuration. A single canopy along one face, with access passages surrounding the remaining sides.
┌─────────────────────────────────────┐
│ Site (e.g. 80m × 50m = 4,000m²) │
│ ┌─────────────────┐ │
│ │ y1 Aisle │ │
│ ├─────────────────┤ │
│ │ Main Bldg 50×30 │ x1 Aisle │
│ │ (Proj 1,500m²) │ 4m │
│ ├─────────────────┤ │
│ │ Canopy 50×7m │ │
│ ├─────────────────┤ │
│ │ y2 Aisle │ │
│ └─────────────────┘ │
│ x2 Aisle │
└─────────────────────────────────────┘
Pattern 2: Annex Layout A (Parallel) + 2-Sided Docks
Office annex sits parallel to the main building. Docks on two sides increase bay capacity but require deeper yard setbacks.
┌───────────────────────────────────────────┐
│ Site (e.g. 90m × 60m = 5,400m²) │
│ ┌─────────┐┌─────┐ │
│ │ CanopyA ││ y3 │ │
│ ├─────────┤│ │ │
│ │ Main ││Annex│ x1, x2 Aisles │
│ │ 50×30 ││15×20│ │
│ ├─────────┤│ │ │
│ │ CanopyB │└─────┘ │
│ └─────────┘ │
│ x4 Aisle │
└───────────────────────────────────────────┘
Dimension Sub-Tabs (TabControl6)
📊 Toggle Sub-Tabs for Micro-Dimensions
TabControl6 at the bottom of the screen displays raw measurement values:
- Aisle Dims: Detail constraints for X1, X2, Y1, Y2.
- Canopy Dims: w1, d1, w2, d2 readouts.
- Annex Dims: Annex X/Y dimensions and coordinate positioning.
📤 Outputs & Results
Key Output Variables
| Output Item | Unit | Description |
|---|---|---|
| Target Site Area | m² | Required land area based on applied BCR. |
| Site Width | m | Total site X-axis dimension. |
| Site Depth | m | Total site Y-axis dimension. |
| Applied BCR | % | The selected Building Coverage Ratio limit. |
| Calculated FAR | % | Auto-calculated Floor Area Ratio (Total Floor Area ÷ Site Area). |
| Passage X / Y | m | Residual yard clearance around the building footprint. |
| Total Gross Floor Area | m² | Sum of Main and Annex gross areas. |
| Building Height | m | Total height (Storey Height × Count). |
Result Display Example
📋 Site Area Results
Visual Export
🖼️ Exporting the Site Map
The rendered 2D schematic can be captured via screenshot and appended to proposals.
Use Cases:
- Sending minimum land requirements to real estate brokers.
- Board-level investment approval decks.
- Preliminary structural engineering briefs.
🖱️ Operating Steps
Standard Workflow
Ensure that the building projection footprint has been finalized in the Building Area tab.
Select the legal BCR limit via the dropdown.
Typical industrial logistics facilities use 50% or 60%.
Click (Calculate Site) to generate dimensions and footprint area.
To match an actual real-world plot, manually adjust the Site Depth. The width will auto-compensate.
Check the Passage X / Passage Y readouts to ensure sufficient room for truck turning radiuses and fire trucks. Adjust x1, x2, y1, y2 if needed and recalculate.
Ensure the FAR stays below 200%. Address any red warning flags.
Inspect the graphical map in the central PictureBox to visually confirm building placement.
If manual dimensions were altered, click (Refresh Display) to update the drawing.
Common Adjustment Scenarios
⚠️ Site Area Exceeds Available Candidate Plot
- Increase BCR (e.g., from 50% to 60%) if legally permitted.
- Increase building storeys to reduce ground projection.
- Eliminate the annex and move offices into the main building.
💡 FAR Exceeds 200% Limit
- Decrease BCR to force the system to require a larger land plot (diluting FAR).
- Reduce the number of building storeys.
- Reduce the gross floor area of the annex.
⚠️ Important Notes & Constraints
Regulatory Compliance
1. Always Verify Legal Zoning Limits
The BCR and FAR values selected in this tool must be cross-verified with actual municipal zoning maps and building codes. Limits change based on corner lot locations, fire safety zones, and specific industrial designations.
2. The 200% FAR Warning
The system triggers a warning at 200% as a general baseline, but actual legal limits vary by zone (from 100% up to 500%). A warning does not necessarily mean the design is illegal if local laws permit a higher FAR.
Calculation Assumptions
3. Rectangular Plot Assumption
This module strictly assumes a perfectly rectangular site. It cannot model L-shapes, trapezoids, or flag-pole lots. For irregular plots, consult architectural CAD engineers.
4. Setback Regulations
Local laws may require buildings to be set back a certain distance from roads or neighboring plots. Ensure you add these setback distances into the y1, x1 passage parameters.
Operational Planning Constraints
5. Parking Space is Excluded
This calculation does not include external parking lots for employees or visitors. You must manually add parking footprint (approx 12-15 m² per car) to the final site requirement.
6. Green Belt Quotas
Many municipalities enforce mandatory green space ratios (e.g., 5-20% of the site). Confirm the Greenery Obligation and increase the site size accordingly.
7. Minimum Passage Widths
Fire safety codes generally require a minimum 4-meter continuous access route from the property line to the building exterior. Ensure at least one passage maintains ≥4m clearance.
System Integration Rules
8. Syncing with the Building Area Tab
If building projection area is modified in the preceding tab, you must manually click Recalculate in this Site Area tab. Values do not auto-sync downstream.
9. Map Accuracy Limitations
The rendered site layout is a conceptual schematic only. Actual blueprints must be drafted by certified architects. Use this schematic solely for initial feasibility and proposal discussions.
Module Boundaries
10. Exception Scenarios
This tool is insufficient for the following complex scenarios:
- Sloped or uneven terrain requiring retaining walls.
- Soft soil sites requiring deep foundation reinforcement.
- Sites with existing structures requiring demolition.
- Plots lacking legally mandated road frontage.
✅ Best Practice for Use
The Site Land Area Tab is the final stage of the physical facility planning workflow. Calculate this only after building footprint is finalized and local zoning restrictions are known, to derive the ultimate land acquisition target.