Keep two different ratios separate
Spaces per household equals spaces divided by households. It is useful for comparing building scale but can hide pressure in a car-heavy complex.
Vehicle capacity equals spaces divided by registered vehicles × 100. Below 100%, the simple shortage is registered vehicles minus spaces.
- Spaces per household = spaces ÷ households
- Vehicle capacity = spaces ÷ registered vehicles × 100
- Shortage = registered vehicles - spaces
Example: 612 households, 420 spaces, 900 vehicles
The complex has about 0.69 spaces per household. Against 900 vehicles, capacity is about 46.7% and the simple registered-vehicle shortage is 480 spaces.
This upper-bound comparison assumes all registered vehicles park at once. Time-of-day field counts are needed to measure actual overnight occupancy.
- Registered vehicles per household: about 1.47
- Spaces per household: about 0.69
- Registered-vehicle shortage: 480
Registers and actual occupancy differ
Rarely parked registered cars, visitors, unregistered cars, and contractors can make records differ from real occupancy. Repeat observations at the same day and time before and after a policy change.
Do not count drive aisles used for double parking as formal spaces without separating their safety and access impact.
Data needed for a fee-policy discussion
Extra-car fees do not create physical spaces, but they can affect registration choices and cost sharing. Track one-, two-, and three-plus-car household counts and registration changes over time.
The calculator compares numerical scenarios; it does not determine bylaw validity or legal parking rights. Review local rules and the proper resident decision process separately.
Design an overnight occupancy count
Observe repeatedly at high-return times such as late weekday and weekend evenings. One count can be distorted by an event, construction, or weather, so compare both average and peak across consistent time slots.
Separate formal spaces, accessible and EV-only spaces, visitor areas, double parking, and blocked aisles. A single total can hide unusable reserved capacity or safety problems.
- Record date, weekday, time, and weather
- Separate formal occupancy from informal parking
- Show differences by building or zone
Compare congestion before and after a policy
Build at least a short baseline for registered vehicles, peak overnight occupancy, and visitor vehicles, then measure the same way after implementation. A fall inside the complex may not be a success if street parking simply rises.
When fees, visitor booking, and permit renewal all change together, their effects are hard to separate. Record each change and compare capacity, complaints, and blocked-access incidents together.
Numbers and limitations for resident meetings
Use one reference date for households, official spaces, registered vehicles, vehicles per household, and field counts. A table of shortage and time-based occupancy supports comparison better than a general statement that parking is severe.
The calculator's grade is not a legal or absolute rating. Layout, mechanical-space availability, commercial allocation, and fire access require separate review.
- Label every source and reference date
- Do not mix registered and observed vehicle counts
- Do not expose household-level vehicle records in public materials