New Build Timeline From Reservation to Legal Completion — What to Expect

The new build purchase timeline is fundamentally different from a second-hand property transaction. There's a fixed exchange deadline, a build period that can last months or years, and a completion that happens on relatively short notice. Understanding what happens at each stage — and what can go wrong — puts you in control.

Day 1 — Reservation

You pay the reservation fee (£500–£2,000) and sign the reservation agreement. The developer holds the property for you for a set period (typically 28–42 days) while you arrange solicitors, mortgage, and exchange.

Immediate actions:

• Instruct your conveyancing solicitor today — ideally within 24 hours
• Submit your full mortgage application within 48 hours
• Confirm all agreed upgrades and incentives are recorded in writing

Weeks 1–4 — Contract Review and Exchange Preparation

Your solicitor reviews the draft contract, raising enquiries with the developer's solicitor. Key areas they will examine:

• Long stop date
• Build specification and what's included
• Estate management charge arrangements
• Warranty scheme (NHBC or equivalent)
• Any unusual clauses or developer-friendly terms

Your solicitor should not rush this review to meet an arbitrary exchange deadline. If significant issues need addressing, the developer should be asked to address them or extend the reservation period.

Mortgage: your application should reach formal offer stage before exchange. Do not exchange without a mortgage offer in place.

Exchange — Typically Day 28–42

Exchange commits you legally to the purchase. You pay your deposit (usually 10% of the purchase price). From this point, your deposit is at risk if you withdraw without a valid legal reason.

Before exchange, confirm:

• Mortgage offer is in hand
• All contractual issues are resolved
• Long stop date is adequate for the build timeline
• Specification is confirmed in writing

The Build Period — Months 1 to 24 (Variable)

This is the longest and most passive stage. The developer builds the property. Your solicitor has little to do. Your mortgage offer is sitting with a clock ticking.

Your active tasks:

• Monitor mortgage offer validity — contact your broker if the expiry date is approaching
• Make specification decisions within the developer's deadlines (kitchen, flooring, bathroom)
• Keep your solicitor informed of your current contact details
• Stay in communication with the developer's sales team for build progress updates

10-Day Notice of Anticipated Completion

When the developer is approaching practical completion, they issue a 10-working-day notice. From this point:

• Notify your mortgage lender immediately (trigger the final draw-down stage)
• Your solicitor prepares completion paperwork
• Arrange removals and temporary accommodation as needed
• Book your pre-completion snagging inspection

Pre-Completion Inspection — Typically 3–5 Days Before Completion

Conduct or commission a full snagging inspection. Submit the snagging list to the developer in writing the same day. Confirm which items will be resolved pre-completion and which will be addressed under the two-year builder warranty.

Legal Completion Day

Funds transfer, keys are released. You own your new home.

On completion day:

• Take your own dated video walkthrough — document condition at handover
• Photograph all meter readings
• Confirm all snagged items outstanding and the developer's schedule for addressing them in writing

Post-Completion — Weeks 1–4

• Register with NHBC (or the relevant warranty scheme) for your specific property
• Commission all appliances and systems (heat pump, solar, EV charger)
• Continue the snagging log for any new issues that emerge
• Contact the developer's aftercare team for any pre-exchange snags that remain outstanding

Set up your Property Passport UK immediately after completion. Store the NHBC warranty, completion certificate, energy documents, and snagging correspondence there — building the most comprehensive property record possible from day one.