Inputs
Large screens use 3 columns, smaller use 2, mobile uses 1.
Run a calculation to enable downloads.
Formula used
This tool first sums all programmed net spaces:
Net Program Area = Σ(room area) + Σ(count × area each)
Then it converts net to gross using one of two common approaches:
- Additive grossing (adds allowances as percentages of net):
Gross = Net × (1 + (Circulation% + Core% + Walls% + Shafts% + Growth%)/100) - Efficiency grossing (targets a net-to-gross ratio):
Gross = Net ÷ (Target Efficiency%/100)
Site estimates are optional and use simplified rules such as footprint coverage and FAR. They are intended for early planning, not final zoning compliance.
How to use this calculator
- Select units, floors, and your civic facility type.
- Enter counts and areas for repeatable rooms.
- Add large public spaces and any special net areas.
- Pick a grossing method and set allowances or efficiency.
- Optionally add FAR, coverage, landscape, and parking inputs.
- Press Calculate, then download CSV or PDF reports.
Example data table
| Scenario | Net program | Gross method | Total gross | Floors | Gross/floor |
|---|---|---|---|---|---|
| Medium city hall | 3,000 m² | Additive +43% | 4,290 m² | 3 | 1,430 m² |
| Community service hub | 1,650 m² | Efficiency 70% | 2,357 m² | 2 | 1,178 m² |
| Public library wing | 2,200 m² | Additive +35% | 2,970 m² | 2 | 1,485 m² |
Tip: replace example values with your program brief and local assumptions.