One of the most common questions we hear is "How long will my extension take?" Here's a realistic breakdown — from the initial idea through to moving the furniture in.
The Full Timeline
1. Design & Drawings
2–4 weeksArchitectural drawings, structural engineer calculations, and design decisions.
2. Planning Permission (if needed)
8–10 weeksFrom submission to decision. Not all projects need this — many fall under Permitted Development.
3. Building Regulations Submission
2–4 weeksSubmitting detailed plans for Building Control approval. Can run in parallel with planning.
4. Contractor Booking & Preparation
2–6 weeksGood builders are booked in advance. We typically have a 4–8 week lead time.
5. Construction
See belowThe actual build time depends on the type and size of extension.
Build Times by Extension Type
What Can Cause Delays?
Bad weather — particularly during groundworks and roofing stages
Planning delays — if the council requests amendments or neighbours object
Material supply issues — especially for bespoke items like bifold doors or steelwork
Client changes mid-build — changes to the specification once work has started
Unexpected ground conditions — poor soil, underground services, or contamination
How We Keep Things on Track
We provide a detailed programme of works before we start, with clear milestones and weekly updates. Our project management approach means you always know what's happening, what's next, and when to expect completion. With 45+ years of experience, we know how to plan for the unexpected and keep your build moving.
Planning Your Extension?
We'll give you a realistic timeline and quote — no surprises, no hidden costs.