The problem
Before offering on a site, a developer needs a feel for the planning position: local plan policies, conservation areas, parking standards, affordable housing thresholds and what has been approved nearby. If a developer appraises 4 sites a month and the planning research takes 3 hours each, that's 12 hours a month, much of it finding the right council documents.
What the AI does
Perplexity answers with inline citations, and Pro ($17, about $17£13€15A$25C$24 a month billed annually) gives fuller Deep Research for longer reports. For each site, the developer asks for the local plan policies that apply to the area, supplementary planning documents on design and parking, the affordable housing threshold and recent decisions on similar schemes nearby, with links to the council's own pages. The developer opens each source, checks the document is current, and takes the points that decide the offer to a planning consultant. The research narrows the questions; the consultant gives the advice.
A worked example
A small residential developer in Kent appraises about 4 sites a month for 2 to 6 homes. The director runs a Perplexity Pro research question on each before deciding which to take to the planning consultant.
Before
3 hours of planning research for each of 4 sites: 12 hours a month
After
About 1 hour each, including checking the council's documents: 4 hours a month
What it's worth
About $532£400€476A$768C$752 a month in time saved, against about $17£13€15A$25C$24 for Perplexity Pro. 2 hours saved on each of 4 sites is 8 hours, at an assumed $67£50€60A$96C$94 an hour.
How to set it up
- Sign up for Perplexity Pro, $17 (about $17£13€15A$25C$24) a month billed annually.
- For each site, ask for the local plan policies, supplementary planning documents, affordable housing threshold and nearby decisions, with links to the council's own pages.
- Open each source and check it is the current adopted version, not a draft or a replaced plan.
- Search the council's planning portal yourself for nearby applications, as the answer may not include them.
- Take the points that decide the offer to a planning consultant before committing.
What goes wrong
- Local plans are replaced, and emerging plans carry weight too. An answer can cite an out-of-date plan, so check the adoption date on the council's site.
- Perplexity can miss applications held on council planning portals. Search the portal yourself.
- A cited summary isn't planning advice. For anything that decides an offer, pay for a consultant's view.
- The free plan gives cited answers but limited Deep Research, and Pro is for one person.