How To Prepare Your Home Before Work Begins – Home Extension Preparation Guide
- Grant Redfern
- Dec 23, 2025
- 3 min read
THE HOME EXTENSION SERIES — PART 6
Your step-by-step guide to getting it right from day one.
🧱 Understanding Home Extension Preparation
Understanding what you can build — and what needs approval.
One of the first questions clients always ask is:
“Do I need planning permission for my extension, or can it fall under permitted development?”
It’s a fair question — and getting this right early on avoids delays, redesigns and unnecessary stress. Here’s a simple breakdown to help you understand the difference 👇
Proper home extension preparation makes the start of your build far smoother, safer and less stressful. These steps help you get organised before the work begins.
🏡 1. What Is Permitted Development?
Permitted Development (PD) is a set of rules that allows you to extend or alter your home without applying for full planning permission — as long as your project meets certain criteria. It’s designed to make smaller, sensible home improvements quicker and easier.
But… it’s not a free-for-all. PD has strict size limits, height limits, boundary rules and material requirements.
📏 2. What You Can Normally Build Under Permitted Development
In most cases, the following work can fall under PD:
Single-storey rear extensions up to a certain depth
Small side extensions on detached/semi-detached homes
Loft conversions (including dormers within set limits)
Certain garage conversions
New windows/doors if they don’t alter the building shape
Outbuildings within size/location rules
These rules can change depending on location, previous extensions and whether your property is restricted (listed, conservation area, etc.).
📝 3. When Planning Permission Is Required
You’ll need full planning permission if:
Your extension exceeds PD size limits
You’re extending too close to a boundary
You're increasing the ridge height of the roof
You want a two-storey rear extension
Your property has already been extended beyond PD allowances
You live in a conservation area, AONB, or your house is listed
The materials don’t match the existing property
If in doubt — assume you need planning until we check.
🧑💼 4. Why We Often Recommend a Lawful Development Certificate (LDC)
Even if your project does fall under PD, we strongly recommend applying for a Lawful Development Certificate.
It’s not permission — it’s proof.
Benefits:
Shows the work is legally compliant
Protects you when selling your house
Prevents disputes with neighbours or the council
Removes any uncertainty for lenders or solicitors
It’s a small cost for massive peace of mind.
👷 5. What Happens If You Build Without Permission When You Should Have It?
The council can issue an enforcement notice requiring you to:
Apply for retrospective permission
Alter the build
Or in the worst case — remove the extension entirely
It’s not worth the risk. Get the approvals sorted early and the whole project flows smoother.
🏗️ 6. Our Process: Planning or PD — We Handle It
With every project, we:
Check your property’s planning history
Measure and confirm PD allowances
Advise whether planning is needed
Work with the architect to design within the rules
Submit planning or LDC applications when required
You don’t have to guess — we guide you through it.
🔎 7. The Golden Rule
Just because your neighbour did it… doesn’t mean you can.
Every house has different allowances, previous extensions, boundaries and restrictions.
Always check first.
👉 NEXT WEEK:
Part 7 — How Long Does A Home Extension Take?
A step-by-step look at the construction process from start to finish..
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