Planning a home extension is exciting, but it can also feel overwhelming. One of the first questions most homeowners ask is: “How long will it take?”
The answer depends on the type of extension, the planning process, and your builder’s efficiency. By understanding the typical extension timeline from first sketch to final finish, you’ll know what to expect – and how to keep your project running smoothly.
At Reltic Extend, we’ve guided countless families across London and Surrey through this journey. Here’s what the timeline really looks like.
Why Understanding the Timeline Matters
A clear idea of the timeline helps you:
Plan family life around construction,
Budget effectively,
Avoid unnecessary stress,
Set realistic expectations about the finished result.
💡 To see how your own project might unfold, start with our Cost Calculator for a quick estimate of costs and scope.
Stage 1: Initial Consultation and Ideas (1–2 Weeks)
Every great project begins with a conversation. During the first stage, you’ll:
Share your ideas, goals, and budget,
Explore possible extension types such as Rear Extensions or Kitchen Extensions,
Receive initial feedback from our team.
At Reltic Extend, we believe in transparency from day one. Our Who We Are page shows how we put homeowners first throughout the process.
Stage 2: Design & Planning (4–8 Weeks)
This is where your vision becomes a plan. Key steps include:
Drafting architectural drawings,
Exploring design options – from Side Extensions to Wraparound Extensions,
Reviewing layout, materials, and features,
Submitting planning applications if required.
Our Planning page explains how we manage applications on your behalf, ensuring your project meets all local council requirements.
Stage 3: Approvals and Final Preparations (4–6 Weeks)
Once designs are complete, the next stage involves:
Securing planning permission (if needed),
Confirming building regulations approval,
Finalising costs and contracts,
Preparing the site for construction.
Our How We Work process means everything is handled for you, removing the stress of paperwork and coordination.
Stage 4: Construction Begins (8–16 Weeks)
This is where your home truly starts to change. Construction time depends on the project size:
Smaller projects like a Kitchen Extension – often 8–10 weeks.
Medium projects like a Side Extension – 10–12 weeks.
Larger projects like a Double Storey Extension – 14–16+ weeks.
We coordinate all trades, keep you updated, and minimise disruption wherever possible.
Stage 5: Interior Finishes (2–4 Weeks)
After the structure is complete, attention turns inside. This includes:
Plastering and painting,
Flooring,
Kitchen or bathroom installation,
Lighting and electrics,
Final fixtures and fittings.
By choosing adaptable finishes, your extension will remain stylish and functional for years.
Stage 6: Handover and Final Checks (1–2 Weeks)
The final stage is just as important as the first. We’ll:
Conduct a full inspection,
Ensure every detail meets our quality standards,
Hand over your extended home with confidence.
For added peace of mind, our Warranty and Insurance ensures your investment is fully protected.
Regional Factors That Affect the Timeline
Where you live can influence project timings:
North London – often involves planning for period homes.
South London – popular wraparounds may extend the design stage.
East London – compact extensions can sometimes be quicker.
West London – premium projects may take longer for finishing details.
Surrey – larger extensions typically extend construction time.
Tips to Keep Your Project on Track
Be clear about your budget from the start.
Avoid design changes mid-project.
Choose experienced builders who manage everything in-house.
Allow extra time for planning approvals.
Stay flexible – delays can happen, but good management keeps things moving.
Final Thoughts
Every extension journey is unique, but understanding the general timeline helps you plan with confidence. With the right partner, your project will progress smoothly from the first sketch to the final handover – leaving you with a beautiful, functional new space.
Ready for a complete extension service?
Want to know how long your extension could take?
👉 Use our free Cost Calculator for a tailored estimate.
Or visit our Who We Are page to learn how Reltic Extend manages projects across London and Surrey – keeping them on time, on budget, and stress-free.
