Permitted Development: A 2024 Guide to Home Improvement without Planning Permission

Permitted Development: A 2024 Guide to Home Improvement without Planning Permission

Matthew Montague
8 minutes


Permitted Development or Lawful Development is a way of extending or renovating your home without the need for a full planning application. Lawful Development is a set of rules or guidelines that outline simple modifications to keep within, which can be anything from small house extensions, loft conversions, garage conversions, etc. 

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Throughout this guide we provide a more in-depth explanation of those rights and what you can and cannot achieve. We always recommend that you obtain a lawful development certificate for the works from your local planning authority, which will confirm that the works carried out fall within Permitted Development, then if you ever sell your property you will then have proof that any changes made were approved. 

Permitted Development VS. Planning Permission 

Permitted Development is a much more cost-effective and time-efficient way of making changes to your home that are officially allowed by your Local Planning Authorities. The reason for the need for planning permission and for permitted development is to retain the character of buildings and areas are protected. Planning permission is therefore required for much bigger changes to a property.

Permitted development rules are designed to restrict the amount of work that you can do to your property without the need for planning permission, to works that will not affect the character of the area, or affect the amenity and enjoyment of your neighbours and their property.  

Image by Simon Maxwell

What Changes Can You Make with Permitted Development Rights? 

Below is some general guidance on what can be achieved without the need for planning permission, however the detailed rules are quite complex, and so you should always consult your architect or local planning authority when considering these works. 

Here is the full list of renovations that can be made within Permitted Development Rights, with full descriptions of each one below. 

  1. Rear Extension 
  2. Side Extension 
  3. Two Storey Extension 
  4. Loft Conversion 
  5. Garage Conversion 
  6. Outbuildings, Garden Rooms and Porches 
  7. Change of Use 
  8. Other Permitted Development Rights 

You can consult with an architect about your project by booking an online consultation at Space That Inspires.

Rear Extensions: 

A rear extension can be up to 3 meters projection for a semi detached, terraced or link detached homes or up to 4 meters projection for a detached property, based on the original building - these changes do not count if the property you own has been previously extended. 

Prior Approval is an extension of permitted development. Prior Approval is the right for you to extend up to 6 meters in length for semi detached or terraced homes and up to 8 meters for detached home, however this process does include neighbourhood consultation.

This is where the council consult with your neighbours to see if they object to the project for reasons such as it overbearing on their land or effecting thier ‘right to light’ etc. 

The maximum height of a single storey rear extension is 4 meters, and the eaves must be below 3 meters at any point where is it within 2 meters of your neighbours boundary. A rear extension much not extend beyond the width of the house, must be minimum 7 meters  away from the rear boundary of the property and must use all the same materials as the original building, so not to stand out. 

Image by Future

Side Extension

Side extensions are a great way to make use of redundant space at the side of a property, which is quite often underused. A side extension cannot be double height, must not exceed more than half the width of the original house, cannot extend beyond the rear wall of the property further than 3 meters for semi detached or terraced properties, 4 meters for detached properties.

Your side extension must not be taller than 4 meters at its highest point and must use materials that match with the original building. 

There is no restriction when it comes to a side extension cutting close to the boundary, apart from the eaves height being lower than 3m when it is within 2m of your neighbours boundary, although we would advise you discuss any plans you have with your neighbour, prior to the renovation. 

Wrap around extensions and a connection between a rear extension and side extension are likely to require a full planning application, although depending on the size of the extension, we would encourage you to ask the opinion of your Local Planning Authority. 

Two-Storey Extension 

The addition of a two storey extension to your property can be of great benefit as it can massively impact the size of the property and its flexibility. In order for your extension to be within the permitted development guidelines, it must be an extension to the back of the property, not the front or side. 

The extension must be no further than 3 metres from the back of the property. 

The height of the roof ridge must not exceed the current roof height at any point, and the roof must be built in the same style, including its pitch, to blend with the current roof. 

The total area of the extension must not exceed more than 50% of the total land around the home, including sheds and any other outbuildings. 

Any second storey windows on the side of the property must have obscured glazing and on any windows on the second floor, they must not be able to open below 1.7m. 

The eaves level of the extension must not be above 3m high if within 2m of the boundary, hence for terraced or semi-detached properties a 2-storey extension is very difficult to achieve under permitted development. 

Image by Mark Ashbee

Loft Conversion 

There are many different types of loft conversions (read more here), including: 

  • Roof Light Conversion 
  • Dormer 
  • Hip to Gable 
  • Mansard 

In order for any external additions to you your loft conversion to fall within permitted development rights, it must be facing the rear of your property, the only modifications that can be made to the front of your property are the addition of roof lights which can project up to 15cm above the original roof surface. 

At the back of the property, the additions can be much more substantial. You can incorporate more than one kind of loft conversion, as long as you stay within the designated guidelines: 

Your loft conversion cannot be higher than the current highest point on the property. 

The space created cannot be more than 30 cubic meters within a terraced property, and not more than 40 cubic meters for a semi detached or detached property. 

Dormers must be set back to a minimum of 20cm from the eaves. 

There must be a 2m clearance in head height above the stairs at the central part of the staircase. 

All new windows that project to the side of the property must be frosted, and any opening parts of these window must be at least 1.7m above the ground. 

Your conversion cannot include balconies or verandas within permitted development, however you can include a juliet balcony without a platform. 

As per all permitted development regulations, the materials and roof structure must match the original building. 

Garage Conversion

Converting your garage into a more usable and liveable space such as a gym or home office within permitted development rights is extremely popular and very simple to do as it only really requires some internal works. The key here is to ensure that the choice of materials, doors and windows match those of the original building / main house so to in keep with the regulations. 

If you are planning to convert your garage into living accommodation, then you are likely to require planning permission. You should also be aware that some new builds come with restrictions towards converting the garage spaces and it is much more strict in conservation areas. We would always recommend to check with your local planning authority before beginning any works. 

Image by Jeremy Phillips

Outbuilding, Garden Rooms and Porches 

It is important to be aware that outbuildings for uses such as a home office or studio,  a gym or a den are all allowed within permitted development rights. However, building a small bedroom or dwelling which people can inhabit does require a full planning application. 

Your outbuilding eg. shed or summer house, can be up to 4 meters in height with a dual pitched roof or 3 meters in height with any other roof eg. a flat roof. 

It must not exceed more than half of the original footprint of the original properties building. 

You are allowed to pave or put decking around the perimeter as long as it is flat against the ground and not above 0.3 meters in height. 

The addition of outbuildings and garden rooms is particularly strict in Areas of Outstanding Natural Beauty (AONB), National Parks, Conservation areas or World Heritage Sites. Within these areas there are additional restrictions such as the maximum area covered by all outbuildings more than 20 meters from the house is restricted to 10 meters. 

Porches have their own set of rules. You can renovate your porch to improve the look of your property and its ‘kerb appeal’ however the extension to your porch cannot extend forward beyond the line of principal elevation. The maximum footprint of a porch is 3 square metes and no more than 3 meters in height. It must also be 2 meters from the boundaries of property and therefore road. 

Change of Use 

Change of use from business to residential is also included within permitted development for ‘Class E’ premises. It is important to get prior approval from the council as well here, however as long as the floor space is not above 1,500 square meters, the property has been used as a commercial space for two years or longer but has been empty for at least 3 months and can’t be a listed building or in a national park etc. 

Class E premises include most of retail (if not deemed essential), offices, restaurants and cafes, old doctors surgeries, nurseries or indoor sports facilities. 

Other Permitted Development Rights

Other changes to your property include the addition of solar panels, satellite dishes, new doors or windows, constructing driveways, modifying external render and claddings and finally, building a new storey or flat (although we recommend consulting with an architect to understand the scope of this). 

Image by ID Systems

Permitted Development Restrictions 

Permitted development rights allow you to make a great selection of renovations to your property without the need for planning permission, however there are restrictions. These include not being able to make renovations to flats or maisonettes.

Permitted development is especially restrictive is National Parks, Areas of Outstanding National Beauty (AONB), conservation areas and not allowed on any listed buildings.

On new build properties and previously converted buildings, there are often further restrictions, you should always check the original planning permission which might well have removed any permitted development rights from this property.

Article 4 Direction & Lawful Development Certificates 

It is important you are aware of ‘Article 4 Direction’ which is a mechanism which a local planning authority will utilise to restrict your right to permitted development rights. A local planning authority would evoke an article 4 direction if they believed the changes you wanted to make would greatly affect the look and character of your property and therefore impact the character of your area. 

This is why, as architects, we always recommend that before you begin any renovations to your property, you obtain a Lawful Development Certificate. A Lawful Development Certificate is not compulsory, however it is proof that your local planning authority are happy with the renovations you have made to your property.

If a local authority decided it was not happy with the renovations, you are at risk of large fines or being forced to put the property back to how it was originally. An LDC is especially valuable if you ever intend on selling your property.

Professional Advice 

Navigating what you want to achieve with your property and then understanding whether or not that can be achieved within permitted development is not always simple to understand.

To ensure that you are complying with regulations and that the changes you are planning to make are the most beneficial to your property, we always recommend to take on a professional opinion of an architect, a planning consultant or your local planning authority. 

At Space That Inspires, you can consult with an experienced architect on your project and gain a better understanding of what you can and cannot achieve, within permitted development rights, for a one-time fee, with no further strings attached.

Book your online consultation with an architect to discuss your project, now.

Image by Chris Snook


Permitted development rights provide homeowners with a valuable opportunity to enhance their properties without the need for planning permission. These rights offer time and cost savings, certainty, and flexibility, making them an attractive option for various home improvement projects.

However, it's essential to understand the specific guidelines and limitations associated with permitted development rights and to seek professional advice when necessary. By staying informed and ensuring compliance with regulations, you can successfully navigate the permitted development process and transform your home to meet your needs and aspirations.

Discuss your project with an architect now, using our online platform at Space That Inspires.

Matthew Montague

Award-Winning Residential Architect

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