Infrastructure Load Calculator
The load a new development adds to each network — water, sewer, electricity and road traffic — from dwellings, occupancy and per-dwelling rates, in the units each network is sized in.
Each network has its own unit and its own rate: liters a day for water, kilovolt-amps for power, vehicle trips for roads.
How the infrastructure load calculator works
Each network has its own unit and its own rate: liters a day for water, kilovolt-amps for power, vehicle trips for roads. A development's load on each is dwellings times occupancy times the per-person rate, or dwellings times a per-dwelling rate.
The traffic figure is the one that most often decides an approval. Ten trips per dwelling per day is the conventional figure for detached housing; apartments generate fewer, and the peak hour carries about a tenth of the day.
Formula: load = dwellings × rate; peak hour trips ≈ 10% of daily
Worked examples
| Inputs | Population added | Note |
|---|---|---|
| 240 dwellings | 624 | about 1,920 trips a day |
| Apartments | 456 | lower per dwelling |
| A small subdivision | 78 | less diversity in the power load |
FAQFrequently asked questions
How many trips does a house generate?
Eight to ten vehicle trips a day for a detached house, four to six for an apartment. The peak hour carries about a tenth.
What is electrical diversity?
Not every home peaks at once, so a transformer serving 240 homes is sized well below 240 times the per-home maximum. The factor falls as the number of homes rises.
Why is sewer flow less than water use?
Because garden watering, car washing and evaporative cooling never reach the sewer. Seventy to eighty per cent is typical for houses.
What kVA does a home need?
Three to five kVA after diversity for a standard home; more with electric vehicle charging and full electrification, which is changing the figure quickly.
Does this determine whether a development is approved?
It is the arithmetic the utility and the traffic engineer both start from. Capacity in the existing network is the other half.
Where these figures come from
- UN-Habitat — Urban Indicators Guidelines — density, green space and public space benchmarks
- World Health Organization — Urban green spaces — the 9 m² per person minimum
- ITE — Parking Generation Manual — parking demand rates by land use
- US Census Bureau — Population and housing — the US national statistics agency
Last checked: September 2026. Default per-capita rates are mid-range figures from national statistical agencies and utility reports; every one is an input you should replace with the local figure.