--- title: "Permitted Development vs Planning: Extensions 2026" description: "When does an extension need planning permission in Hertfordshire and Essex? Permitted development limits, neighbour consultation, and what we handle for you." lang: en-GB json-ld: | [ { "@context": "https://schema.org", "@type": "BlogPosting", "headline": "Extensions: When You Need Planning Permission and When You Don't", "description": "When does an extension need planning permission in Hertfordshire and Essex? Permitted development limits, neighbour consultation, and what we handle for you.", "mainEntityOfPage": "https://jandco-contractorsltd.co.uk/blog/permitted-development-vs-planning-extensions/", "datePublished": "2026-05-07", "dateModified": "2026-05-07", "author": { "@type": "Person", "name": "Jamie Pocock", "jobTitle": "Owner & Lead Contractor", "worksFor": { "@id": "https://jandco-contractorsltd.co.uk/#business" } }, "publisher": { "@type": "Organization", "name": "J&Co Contractors", "url": "https://jandco-contractorsltd.co.uk", "logo": { "@type": "ImageObject", "url": "https://jandco-contractorsltd.co.uk/logo.png" } }, "image": [ "https://jandco-contractorsltd.co.uk/assets/upload-009-DFap0EVo.jpeg" ], "articleSection": "Building", "keywords": "Extensions, Planning" }, { "@context": "https://schema.org", "@type": "BreadcrumbList", "itemListElement": [ { "@type": "ListItem", "position": 1, "name": "Home", "item": "https://jandco-contractorsltd.co.uk/" }, { "@type": "ListItem", "position": 2, "name": "Blog", "item": "https://jandco-contractorsltd.co.uk/blog/" }, { "@type": "ListItem", "position": 3, "name": "Extensions: When You Need Planning Permission and When You Don't", "item": "https://jandco-contractorsltd.co.uk/blog/permitted-development-vs-planning-extensions/" } ] }, { "@context": "https://schema.org", "@type": "FAQPage", "mainEntity": [ { "@type": "Question", "name": "How do I know if my house is in a Conservation Area?", "acceptedAnswer": { "@type": "Answer", "text": "Check your local council planning portal — East Herts, Uttlesford and Epping Forest all have interactive maps. Or we'll check on your free site visit." } }, { "@type": "Question", "name": "Can you start work as soon as planning is approved?", "acceptedAnswer": { "@type": "Answer", "text": "Yes — assuming structural calcs, Building Regs application and party wall (if applicable) are also in place. We line these up in parallel with the planning process to avoid delays." } } ] } ] --- We use essential cookies to run this site, and optional cookies only with your consent. [Cookie policy](/cookie-policy/) AcceptReject Open 7 days · Hours vary by day · 25 years' experience [Office: 01279 216 215](tel:01279216215) | [Mobile: 07379 964569](tel:07379964569) [![J&Co Contractors logo](/assets/jandco-logo-DkXiFtbE.png)](/) Services Areas [About](/about/) [Our Work](/our-work/) [Blog](/blog/) [Reviews](/reviews/) [Contact](/contact/) [01279 216 215](tel:01279216215) [Free Quote](/contact/) 1. [Home](/) 2. [Blog](/blog/) 3. Extensions: When You Need Planning Permission and When You Don't Building # Extensions: When You Need Planning Permission and When You Don't Updated May 2026 8 min read By Jamie Pocock ![Single-storey rear extension built under permitted development in Hertfordshire](/assets/upload-009-DFap0EVo.jpeg) Most homeowners assume any extension needs planning permission. In reality, around 60% of the extensions we build go through Permitted Development — no full planning application needed, faster start, lower fees. Here's how to tell which route applies to your project, accurate for England in 2026. ## What Permitted Development actually allows Under the General Permitted Development Order, a semi-detached or detached house can extend without full planning permission within these limits: - **Single-storey rear:** up to 6m for semi/terrace, 8m for detached, max 4m height, max half the garden width - **Side extension:** single-storey only, max 4m high, max half the original house width - **Two-storey rear:** up to 3m projection, min 7m from rear boundary, matching roof pitch - **Materials:** must be similar appearance to the existing house ## What disqualifies you from PD Permitted Development is removed in: - Conservation areas (parts of Bishop's Stortford, Saffron Walden, Sawbridgeworth) - Areas of Outstanding Natural Beauty - Listed buildings (always need Listed Building Consent) - Properties where PD rights have been removed by an Article 4 direction - Any house created from a flat conversion or originally a maisonette ## The Larger Home Extension scheme (Prior Approval) Single-storey rear extensions between 4–6m (semi/terrace) or 4–8m (detached) need Prior Approval — a lighter-touch process than full planning. Council notifies neighbours; if no objections within 21 days, you're approved. Takes 6–8 weeks total. ## When you definitely need full planning - Two-storey extensions exceeding PD limits - Anything in a Conservation Area or AONB - Side extensions on a corner plot facing a highway - Any extension on a Listed Building (also needs LBC) - Building over the boundary or close to a public right of way Full planning takes 8–13 weeks in our local councils (East Herts, Uttlesford, Epping Forest) and costs £258 in application fees. ## Building Regulations apply either way Critically — even if you don't need planning, you still need Building Regulations approval. This covers structural, thermal, fire and ventilation compliance. As [CRC-certified contractors](/about) we can self-certify most elements and coordinate the building inspector for you. ## What we handle for you On every [extension project](/building-extensions/) we manage: - Initial planning route assessment (free, on-site) - Architect introduction or working from your existing drawings - Planning or Prior Approval submission - Structural engineer coordination - Building Regulations submission and inspector liaison - Party Wall agreements where needed - Full build through to handover ## Realistic timeline 2026 From first conversation to keys-in-hand on a typical single-storey rear extension under PD: **4–6 months**. Two-storey under full planning: **7–10 months**. We give you a Gantt chart on day one so you can see exactly what's happening when. Extensions Planning FAQs ## Frequently asked questions ### How do I know if my house is in a Conservation Area? ### Can you start work as soon as planning is approved? ## Thinking about an extension? Start with a free planning chat. We'll visit your home, tell you straight whether your project is PD, Prior Approval or full planning — and what realistic costs and timelines look like. [See our extensions service](/building-extensions/) [01279 216 215](tel:01279216215) More from the blog ## Keep reading [ ![Pitched tile roof inspection on a Hertfordshire home before winter](/assets/wa-435-169-BMBPQKLs.jpeg) Roofing ### Winter Roof Checklist: 12 Things Every Hertfordshire Homeowner Should Check Before December The 12 things that cause 90% of winter roof leaks in Hertfordshire — and how to spot them in 20 minutes from the ground. Read article ](/blog/winter-roof-checklist-hertfordshire/)[ ![EPDM flat roof replacement on a domestic extension in Bishop's Stortford](/assets/wa-435-47-C__F_29U.jpeg) Roofing ### 5 Signs Your Flat Roof Needs Replacing — Not Just Patching When patch repairs stop being economic. Five visible signs that a full flat roof replacement is the right call. 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