From Vacant Lot to Feasibility Report in 15 Minutes

This is a speed run. If you want the full theory of lot analysis — what setbacks, occupancy limits, floor-area ratios and height limits are, and why they decide a lot's real value — read our companion guide on how to check if a lot is buildable first. This article assumes you know why and shows you how fast: one candidate lot, in the Site Feasibility Calculator, from blank screen to PDF report in a quarter of an hour.

Set a timer. Here's the clock.

Minutes 0–2: Gather the two inputs

You need exactly two things before touching the tool:

The boundary. The lot's technical description from the title or survey plan — corner points and distances — or, for a first-pass screen, the boundary as best you can trace it. (For a purchase decision, always work from the title; for shortlisting, tracing is acceptable as long as you re-run the numbers properly later.)

The rules. The zoning classification and its four parameters: setbacks per side, PSO (percentage of site occupancy), FLAR (floor-to-lot-area ratio), and BHL (building height limit). Source: the local zoning ordinance or a call to the planning office. Write them on a sticky note.

Pro tip: If you're screening several lots in the same district, the rules are usually identical across them — gather once, run many. The per-lot marginal time drops to about ten minutes.

Minutes 2–5: Define the boundary

Open the calculator and define your plot: draw the boundary on the map, or enter the corner points to match the technical description. Irregular shapes are fine — the tool works with whatever polygon you give it. Check the computed lot area against the documented area; if they disagree by more than a rounding error, fix the boundary before proceeding. Every downstream number depends on this polygon.

Transfer the sticky note into the compliance panel: front, side, and rear setbacks; PSO; FLAR; BHL. Take thirty seconds to double-check units and which side is the frontage — the classic error in fast runs is assigning the front setback to a side boundary, which silently distorts the whole envelope.

The tool draws the buildable envelope over the lot and reports the governing numbers:

• Allowable footprint — the smaller of the setback envelope and the PSO cap, with the tool showing which one governs
• Maximum gross floor area — lot area × FLAR
• Implied storeys — max floor area ÷ footprint, checked against the BHL

Three minutes here is enough to answer the screening question: does the allowable building support the project you have in mind? If you're carrying a space program (say, ~210 m² gross for a family house, or a target unit count for a small development), the comparison is immediate.

Because everything recalculates live, spend two minutes on the questions a static calculation can't answer. What if the side setback is actually 3 m, not 2 m — how much footprint dies? What does the same lot yield under the adjacent commercial zone's parameters? If the BHL is the binding constraint, how much of the FLAR allowance is actually reachable? The what-ifs are where a lot's sensitivity shows — two lots with similar headline numbers can behave very differently when one parameter moves.

Minutes 13–15: Export the report

One click generates the PDF feasibility report: boundary, parameters, envelope drawing, and the compliance summary. File it against the lot's listing. If the lot fails, the report is your record of why — worth its weight when a seller drops the price two months later and you need to remember whether the problem was price or planning.

What the 15 minutes buys you

Not a purchase decision — a filter. The speed run tells you which lots deserve the slow, expensive diligence: title verification, easements and road-widening checks, hazard overlays, soil, utilities, and a licensed professional's confirmation of the applicable rules. Running the filter first means you pay for deep diligence only on lots that can actually hold your project — and you walk into every negotiation already knowing what the land can legally carry.

Screening a shortlist this weekend? The math says an afternoon covers ten lots:

Open the Site Feasibility Calculator → — free, no account, and lot data never leaves your browser.

Results are indicative screening estimates based on the parameters you enter. Zoning regulations vary by locality and change over time. Verify all rules with your local planning office and have findings confirmed by a licensed professional before any purchase, permit, or financial commitment.