Considering a home extension? Understand when you need permission, what may be exempt, how to apply, and the pitfalls to avoid—so your project stays smooth, compliant, and stress-free.
Need planning advice fast?
Get clear answers on extensions, drawings, and permissions without the stress.
Considering a home extension? Before you break ground on your project, it’s essential to navigate the somewhat murky waters of planning permission. While the idea of expanding your living space is exciting, the legalities can be daunting. Whether you’re dreaming of a new kitchen, a sunroom, or a two-storey addition, understanding when you need permission and the costs involved is crucial.
Understanding Planning Permission: What You Need to Know
Planning permission means getting formal approval from your local planning authority before beginning your project. This ensures your extension complies with building standards and local policies. Without it, you risk enforcement action or even demolition.
Types of Home Extensions That Require Planning Permission
You will usually need permission if your extension:
- Exceeds permitted size or height limits (Planning Portal guidance)
- Is in a conservation area or attached to a listed building
- Creates new dwellings or alters the property’s use
- Significantly impacts neighbours or the street scene
For more detail, see our Buckinghamshire guide (many principles apply nationwide).
Common Home Extensions That May Not Need Planning Permission
Some projects fall under Permitted Development rules. Examples:
- Small rear kitchen extensions
- Loft conversions that don’t alter the roofline
- Garden outbuildings (subject to limits)
The Planning Permission Application Process Explained
The process typically involves preparing planning drawings, submitting via the Planning Portal, paying the relevant planning permission cost, and awaiting council consultation and decision.
Key Factors Influencing Planning Permission Decisions
- Impact on neighbours (light, privacy, noise)
- Aesthetic fit with surroundings
- Environmental considerations (flood risk, biodiversity)
Consequences of Building Without Planning Permission
Ignoring the rules may lead to enforcement, fines, and even demolition. It also affects your property value and can block future sales. Retrospective applications are possible but risky.
How to Check if You Need Planning Permission
Use the Planning Portal’s interactive guides or check with your local authority. Unsure? Get tailored advice from Plans Made Easy.
Tips for a Successful Planning Permission Application
- Use clear drawings and professional support
- Respect neighbours and reduce objections
- Include sustainable features
Alternatives to Planning Permission: Permitted Development Rights
Some single-storey rear extensions or lofts fall under PD. For clarity, see our dedicated guide: Do I Need Planning Permission?
Conclusion: Navigating the Planning Permission Landscape for Your Home Extension
Securing approval can seem daunting, but with clear information, accurate drawings, and a professional approach, it’s manageable. Explore more in our complete planning permission guide and related resources below.
Ready to move your project forward?
Plans Made Easy can prepare compliant plans, manage submissions, and guide you from idea to approval.
🛠️ Next week: Garage Conversions — what you need to know before building inside your home.
Basement Conversions UK: Costs, Design, Rules & Building Regulations Explained
Transform your unused cellar into bright, livable space with a compliant basement conversion. This complete UK guide explains costs, waterproofing, planning rules, and building regulation essentials — including structure, drainage, fire escape, and ceiling height. Learn every step from idea to approval with trusted advice from Plans Made Easy.
Plans for Building Regulations (UK Guide) – What Drawings You Need & When
Building Regulations plans show exactly how your project will be built — safely and to code. Learn what drawings you need, how they differ from planning permission, who prepares them, and typical costs. A clear UK homeowner’s guide to getting compliant plans approved quickly by Building Control.
Planning Permission Loft Conversion (UK) – Rules, Costs & Council Quirks Explained
Thinking of converting your loft? Discover when you need planning permission and when you can build under Permitted Development. This guide explains UK rules, council quirks, conservation area limits, and typical costs — helping you plan a compliant loft conversion that adds value and avoids refusals.
Planning Permission in Herefordshire: step-by-step guide, council policies, conservation & AONB checks, timescales, fees, and how to avoid refusals.
Planning Permission in Herefordshire explained: find out when you need approval, how Permitted Development works, and the local council “quirks” that affect extensions, lofts, and garden rooms. Covers conservation areas, AONB rules, sewers, fees, timescales, and common refusal reasons — with a step-by-step guide to smooth approvals.
Building Over Sewers – What You Must Know
Building over sewers in the UK requires a Build Over Agreement from your local water authority. Our guide explains when consent is needed, how the application works, typical costs, timelines, and local quirks. Avoid costly mistakes, protect your property value, and ensure Building Control approval before you start work.
Do Garden Rooms Need Planning Permission? UK Rules & Council Quirks
Most garden rooms in the UK don’t need planning permission if they meet Permitted Development rules, such as size, height, and location limits. But conservation areas, sleeping accommodation, or oversized designs can trigger full approval. Learn the rules, council quirks, and Building Regulation requirements before you start
