3 free, no account
Ask, and see what it read.
A planning assistant is only worth anything if you can check it. Ask Wren retrieves before it writes, shows you the passages it used, and verifies its own citations before it stops speaking.
Retrieval first, then language.
The order matters. A model asked to recall planning policy will produce something that reads exactly like planning policy and is wrong in the details that decide applications.
So the model is never asked to recall. Your question is searched against the ingested corpus using both meaning and exact terms, the passages that come back are placed in the prompt, and the answer is composed from them. When it finishes, the citations in it are checked against the sources that were actually retrieved.
Anything it could not ground, it says it could not ground. The confidence it reports is about the retrieval, not about the fluency of the sentence.
Ask Wren
Can I build a rear extension deeper than three metres on a terraced house in a conservation area?
Not under permitted development. The larger home extension route, which allows up to six metres on a terrace, is not available in a conservation area: the Order removes it in designated land. You would be making a full householder planning application.
Your council will also expect a heritage statement, because the duty on the decision-maker under section 72 applies to the character and appearance of the area whether or not your own building is listed.
Read from
- General Permitted Development Order 2015, Sch. 2, Pt 1, Class A
- Planning (Listed Buildings and Conservation Areas) Act 1990, s.72
- Westminster City Plan 2021, Policy 39
Citations verified · corpus checked 2 hours ago
The rule
An assistant that cannot show you its sources is asking you to trust its tone. Planning is decided on paragraph numbers, and a paragraph number that sounds right is worth nothing.
Scope
What it is good at, and what it is not
Good at
- Whether something is permitted development, and which Class
- What a specific local policy requires, quoted from the adopted text
- Which documents your council will expect, and why
- How your authority tends to decide this kind of application
- What a term in a decision notice or a condition actually means
- Where in the framework a particular test lives
Not for
- Advice you can act on without a professional. Nothing here is signed.
- Anything turning on documents it has not seen.
- Case law before roughly 2001, which the index does not cover, and which it will decline rather than guess at.
- Predicting what a named officer will do.
Record
Every question is kept, and it is yours.
Not for us. For you, and for the professional standards that now apply to anyone using AI in this industry.
Every question, the answer, the model, the passages retrieved, the citations verified and the ones that could not be, are written to an append-only log on your account. You can export the whole thing as a spreadsheet or as JSON at any time, and nothing in the product can edit a row after it is written.
You can also generate an AI Use Disclosure: a plain statement of what was used and on what policy basis, naming the actual version of the framework in force and the timestamp of the last corpus check. It exists because the RICS Professional Standard on the responsible use of AI came into force on 9 March 2026, and a disclosure that does not name the real policy basis is not a disclosure.
Questions
Questions
Is this just a chatbot with a planning prompt?
No. Every answer is retrieved before it is written. The question is searched against an ingested corpus of national policy and adopted local plans, the passages that come back are put in front of the model, and the answer is written from those. The retrieved passages are shown to you, so you can check the answer against what it read rather than against what it sounds like.
Does it know about my specific site?
If you have drawn one, yes. The current site context travels with every question: the constraints found on it, its authority, its flood zone, its planning history. Ask about setback distances with a boundary drawn and the answer is about your boundary.
Can I rely on it?
Rely on it to be well informed and to show you where it got that. Do not rely on it as advice. Nothing Ask Wren says carries a professional signature or professional indemnity, which is the whole reason a paid case routes through a chartered planner instead.
What does it cost?
Three questions with no account at all. After that it is one credit per question, and new accounts start with 25.
Is there a version for one council?
Yes. Every council page carries an assistant scoped to that authority alone, answering over the full set of data Wren holds for it: adopted policies, levy schedule, approval rate, decisions on time, applications per year, housing delivery, housing need and plan status.
Start here
Ask it something hard.
3 questions with no account and no card. It will show you what it read.