Understanding Permitted Development in the UK: A Complete Guide by Arch One
Last updated: November 2025
Are you dreaming of extending your home, converting your loft, or adding a garden office — without the hassle of a full planning application? You might be able to do it under Permitted Development Rights (PDR).
At Arch One, we specialise in helping homeowners across the UK make the most of their property through smart, compliant, and beautifully designed projects. In this guide, we’ll walk you through everything you need to know about permitted development — what it covers, recent changes, and how our architectural expertise ensures your project stays both lawful and inspiring.
What is Permitted Development?
Permitted Development Rights (PDR) are a set of national planning permissions granted by the UK Government that allow certain types of building work and changes of use to be carried out without needing a full planning application.
In essence, it’s the government’s way of simplifying the planning process for smaller-scale developments — from single-storey extensions and loft conversions to garage conversions and outbuildings.
However, the rules can be complex and vary depending on your location, property type, and previous alterations — which is where working with an experienced architectural team like Arch One becomes invaluable.
Types of Projects Covered by Permitted Development
Depending on your property, you may be able to carry out the following works under PDR:
1. Single-Storey Rear Extensions
- Detached houses can typically extend up to 8 metres from the rear wall.
- Semi-detached or terraced houses can usually extend up to 6 metres.
- The height limit is generally 4 metres, but this can vary depending on roof type and location.
Arch One Tip: Even under permitted development, it’s often wise to submit a Lawful Development Certificate (LDC) to your local authority for peace of mind.
2. Loft Conversions
Transforming your unused loft space is one of the most cost-effective ways to add both space and value to your home.
Under PDR:
- You can add up to 40 cubic metres of roof space for terraced houses.
- Detached and semi-detached homes can add up to 50 cubic metres.
- Dormer extensions must not exceed the height of the existing roof and cannot extend beyond the plane of the front roof slope.
💡 Pro Tip: Velux or roof light installations often fall under permitted development too, provided they do not project more than 150mm from the existing roof plane.
3. Garage and Outbuilding Conversions
Turning a garage or shed into a functional living or office space has become increasingly popular — especially with the rise of remote working.
Under permitted development, you can typically:
- Convert an existing garage into habitable space (subject to local covenants).
- Build a detached outbuilding such as a garden office or gym, provided it is no more than 2.5 metres high (if within 2 metres of the boundary) and doesn’t cover more than 50% of the garden area.
4. Two-Storey Extensions
Since updates to permitted development rights, some properties can now include two-storey extensions under specific criteria:
- Must not extend more than 3 metres beyond the original rear wall.
- Roof pitch must match the existing house.
- Cannot be within 7 metres of the rear boundary.
🏠 Arch One Insight: Not all homes qualify for this — we always conduct a detailed feasibility study to ensure compliance before proceeding.
Where Permitted Development Does Not Apply
While PDRs are generous, there are limitations. You’ll likely need full planning permission if your property is:
- In a Conservation Area
- Within a National Park
- In an Area of Outstanding Natural Beauty (AONB)
- A Listed Building
- In a World Heritage Site
Additionally, some newer developments have their permitted development rights restricted or removed under what’s called an Article 4 Direction — something the Arch One team always checks during our initial planning research.
Why Work With an Architect for Permitted Development?
You might think that because planning permission isn’t required, you don’t need an architect — but this is a common mistake. Here’s why working with Arch One can make all the difference:
- Maximising Space and Light
Our architects ensure that every square metre is designed to work beautifully and efficiently. - Navigating Complex Regulations
We handle all technical drawings, compliance checks, and can submit your Lawful Development Certificate to confirm the project is lawful. - Future-Proofing Your Home
Even if your project doesn’t need planning permission now, we design with future regulations, resale value, and sustainability in mind. - Managing the Entire Process
From concept design and 3D visualisations to builder coordination and building control approvals — we manage every step.
Recent Updates to Permitted Development Rights (2024–2025)
The UK Government periodically updates permitted development regulations to support housing growth and sustainability. As of late 2025, key highlights include:
- Eased restrictions for upward extensions on detached homes and certain blocks of flats.
- Greater flexibility for converting commercial properties into homes under Class MA.
- Sustainability allowances for solar panels, air-source heat pumps, and energy efficiency retrofits.
At Arch One, we continuously monitor these policy shifts to ensure your project takes full advantage of the latest opportunities.
How Arch One Can Help
Whether you’re planning a rear extension, loft conversion, or outbuilding, our expert architects can:
- Assess your project’s eligibility under permitted development.
- Provide detailed measured surveys and concept designs.
- Prepare and submit your Lawful Development Certificate.
- Guide you through building regulations and construction tendering.
We pride ourselves on delivering creative, compliant, and client-focused architecture that enhances your lifestyle and adds long-term value to your property.
Start Your Permitted Development Project with Arch One
If you’re considering extending or improving your home under permitted development, let our experienced architects guide you from concept to completion.
📍 Based in the UK and serving clients nationwide, Arch One specialises in residential extensions, loft conversions, and modern refurbishments that elevate everyday living.
👉 Get in touch today to book your free initial consultation and discover what’s possible with your property.