Converting a house into flats or a house in multiple occupation usually adds residents without adding parking. Councils often want evidence that nearby streets can absorb the extra cars. That evidence is a parking stress survey.
The Lambeth methodology
Most councils accept a survey approach first developed by the London Borough of Lambeth. It counts parked cars overnight, when residents are home, on streets within roughly 200 metres walk of the site.
- Counts in the early hours of the morning, on two weekday nights
- Avoiding school and public holidays
- Every street within about 200 metres walking distance
- Kerb lengths measured to work out how many cars can legally park
What the results show
Parking stress is the number of parked cars as a share of the available space. Many councils treat 85% or more as high stress, where finding a space becomes difficult. The survey then adds the likely demand from the new scheme to see whether that tips the area over.
Before you commission one
- Check whether the council actually requires one for this scheme.
- Agree the survey area and nights with the highways officer.
- Look at car ownership data first: some schemes generate very little demand.
If the street is already busy
A high result is not necessarily the end. Permit restrictions on new residents, car club access, cycle storage and a good location can all help. The survey sets out the facts. The case is made in how you respond to them.
General information, not advice on a specific site. Policy and guidance correct as of October 2026.