How to assess planning risk on a development site
Planning risk is the gap between what you want to build and what you are likely to get approved. Here is how to assess it systematically.
The cost of getting planning risk wrong
Every development site carries planning risk -- the probability that your application will be refused, or approved with conditions so onerous they undermine viability. Understanding this risk before you commit capital is fundamental to sensible property development.
The eight categories of planning risk
Policy risk: How well your proposal aligns with Local Plan policies. A high local refusal rate is a strong signal.
Heritage risk: Impact of listed buildings, conservation areas, scheduled monuments, and archaeological priority areas.
Environmental risk: Green Belt, AONB, National Parks, SSSIs. Green Belt carries the highest risk due to the strong presumption against development.
Flood risk: Scored directly from flood zone classification. Zone 3b is often a show-stopper.
Amenity impact: Overlooking, overshadowing, noise, disturbance to neighbours. Larger schemes carry higher risk.
Highways and access: Can the road network handle the traffic? Highways objections remain one of the most common reasons for refusal.
Design sensitivity: How important is design quality in this location? Sites in conservation areas face higher scrutiny.
Viability and obligations: Can the scheme bear affordable housing (often 35%), CIL, and S106 costs?
What drives planning success
Precedent matters enormously. Similar schemes approved nearby is strong evidence yours should be too.
Five-year housing land supply: If the council cannot demonstrate this, the "tilted balance" shifts presumption towards approval for housing schemes.
Pre-application advice from the local planning authority gives you a direct read on the officer's likely recommendation.
The manual approach
Manually assessing planning risk means reading the relevant Local Plan policies (hundreds of pages), checking planning history, reviewing Environment Agency flood data, and searching Historic England's database. A thorough risk assessment for a single site might take a planning consultant half a day.
MarketCode's planning-check skill does the first pass: every designation and constraint at the address graded by severity, recent and decided applications nearby, the flood position, and what it means for a stated proposal.