Off-plan purchases carry two risks personal buyers routinely under-price: developer solvency and delivery slippage. Getting these wrong costs investors far more than a half-point pricing adjustment. Getting them right is mostly about asking the right questions before exchange.

This is the 22-point due-diligence checklist we use internally. None of it is complicated; almost none of it appears on typical glossy brochures.

Developer and scheme

  1. How many schemes has this developer delivered in the last 10 years? Under 3 is a red flag.
  2. What is the average delivery slippage against original completion date across those schemes?
  3. Who is the main contractor? Is it tier-one, tier-two or own-labour?
  4. What is the warranty provider? NHBC, Buildzone, Premier Guarantee and ICW are acceptable. Anything else needs justification.
  5. Is the warranty certificate issued at exchange or deferred? Deferred is a no.
  6. What percentage of units are already reserved or exchanged?
  7. Are the remaining prices the same as opening prices, or have they been discounted? Discounts on a hot scheme late-cycle mean something is wrong.

Legal and payment

  1. What is the exchange deposit and what percentage is staged to milestones?
  2. Who holds the deposit, the developer operating account or an escrow arrangement?
  3. What are the exact longstop and cancellation provisions? What happens if the build runs 24 months late?
  4. Can contracts be assigned before completion, and is there an assignment fee?
  5. What is the lease length and are ground-rent terms compliant with the Leasehold Reform Act 2022?
  6. Is the service-charge budget published, and what is the 5-year projection?

Build and delivery

  1. What is the build contract type: fixed-price, cost-plus or guaranteed-maximum-price?
  2. Is the development bonded or drawdown-based?
  3. Who is the independent monitoring surveyor and can we see their most recent report?
  4. What is the planned internal specification (flooring, worktops, kitchen brand)? Get it in writing.
  5. Are utilities connections guaranteed at completion or scheduled separately?

Financial and exit

  1. What rental comparables are available for the immediate postcode, in similar new-build stock?
  2. Are you entitled to any rental guarantee, and is the counterparty independently capitalised?
  3. What is the resale market within 400 metres over the last 24 months?
  4. What is the lender stance on this scheme? Have any mainstream BTL lenders declined it?

Our rule of thumb

If fewer than 16 of the 22 questions have clean answers, we pass.

The developers who answer all 22 with confidence are the ones whose schemes we actively introduce to clients. Those who bristle at the questions are telling you everything you need to know.

If you would like to stress-test a specific scheme against this checklist, ask.