Worked example
A Skokie R-1 addition, checked before the city does
This is how a real pre-flight check works. A two-story residential addition over an existing single-family dwelling in Skokie, IL — uploaded, extracted, verified, and reviewed against the Village's adopted Chapter 118. Illustrative example.
1 · What Pre-Flight extracted from the set
| Project type | Residential addition |
| Zoning district | R-1 — Single-Family Residential |
| Floor area | 3,900 sq ft (proposed total) |
| Lot area | 6,562.5 sq ft |
| Lot width | 52.5 ft |
| Lot depth | 125 ft |
| Stories | 2 |
| Lot coverage | 45% |
| FAR | 0.59 |
| Building height | 28 ft |
| Front setback | 21.96 ft |
| Side setback | 2.75 ft |
| Rear setback | 46.7 ft |
| Construction type | Type III-B |
You verify these before the review runs — the model is good at reading a cover sheet, and the human is good at catching a mis-read dimension. 97% confidence on this set.
2 · What the review returned
Side yards (lot width under 85 ft): two side yards, neither less than 6 ft
Proposed
2.75 ft side yard
Code limit
6 ft minimum
The proposed side yard is below the R-1 minimum. Expect a redline before resubmittal.
Accessory (garage) rear setback — evaluated against accessory rules, not principal yards
Proposed
3.83 ft garage rear setback
Code limit
Confirm accessory section (garage counts toward 50% principal+accessory cap)
Garage setbacks use the accessory standards; confirm the exact value against the adopted text.
Floor area ratio maximum 0.6
Proposed
0.59
Code limit
0.6
FAR complies with the R-1 maximum.
Findings cite the exact municipal section (Sec. 118-124). A generic chatbot would have recited a model-code setback that may not apply — Pre-Flight binds to Skokie's adopted text. Why not just use a chatbot?
3 · What you still verify
- · Confirm the lot width/depth against the survey (drives the side-yard rule).
- · Confirm the garage is a detached accessory structure (its setbacks differ from the house).
- · Check the adopted edition date of Chapter 118 on the Village site.
Pre-Flight is not a permit, not legal advice, and not a substitute for a licensed design professional or the authority having jurisdiction. The city still decides.