This article explains the planning and building control requirements for adding external wall insulation, also known as cladding, to a property or retrofitting an external wall with solid walls in the UK. The process involves applying a layer of spray foam to the existing brickwork.
The aim of this post is to provide property owners who want to externally insulate their home with an easy to follow guide through the planning and building control process. It will also provide advice on external wall insulation, including design and any additional work that may be required.
Some properties do not require planning permission because they fall under “permitted development”, as long as the materials used are similar to those used in the property’s construction. This guide will explain when this is true and when it is not.
This guide will also go over how to determine whether you need Building Control approval for external wall insulation planning permission and if so, how and when to apply for it with the local planning authority. Make sure to gather all the necessary documents and obtain the required certificate.
External Wall Insulation Requirements
External wall insulation (EWI) is a popular energy-saving measure that involves insulating the exterior walls of a property to reduce heat loss and improve energy efficiency. If you are considering adding EWI to your property, there are several planning and building control requirements that you should be aware of:
EWI Planning requirements:
- Planning permission is usually required for adding EWI to a property but it depends on a number of factors such as if you live in a listed building, a conservation area, if the property is a flat etc. In these cases, you may need to obtain planning permission from your local authority.
- You should also consider whether the EWI will change the appearance of your property. If it does, you may need to apply for planning permission to ensure that the changes are in keeping with the local area.
EWI Building control requirements:
- Adding external wall insulation to your property is considered a “material alteration” under building regulations. This means that you will need to comply with the relevant building regulations, including obtaining planning permission and building control approval from your local authority.
- The EWI system you choose must comply with the relevant British Standards and building regulations, and should be installed by a competent installer who is registered with a competent person scheme.
- Your local authority building control department may need to inspect the EWI installation to ensure that it meets the required standards and regulations.
- The EWI installation must meet fire safety standards in the event of a fire. The system should be designed to prevent the spread of fire, especially to neighbouring properties.
In addition to these requirements, it is also important to consider the practicalities of adding External Wall Insulation (EWI) systems to your home. For example, you will need to ensure that the EWI system is suitable for your property type and location and that it does not cause any issues with damp or condensation. You should also consider whether any additional works, such as re-routing services, repositioning gas/electric metres or fixing defects will be required before the EWI installation can take place. It is essential to consult with your local planning authority to ensure compliance with fire safety regulations.
What is Permitted Development
Permitted development refers to certain types of building works and changes of use that can be carried out without the need to obtain planning permission from the local council. The rules and regulations surrounding permitted development are set out in the Building Regulations and the guidance is provided by each individual local council, therefore the policies can vary slightly.
Permitted development rights usually apply to relatively minor alterations or extensions to existing buildings, as well as changes of use that do not significantly alter the character or appearance of a building or the local area. These rights are applicable to various systems and also cover fire safety measures.
Permitted development rights generally do not apply to flats or maisonettes in the same way they do for houses. This means that if you live in a flat or maisonette and wish to carry out any external alterations, including adding EWI systems, you will most likely need to apply for planning permission. It is always best to consult your local planning authority for specific advice on your particular property and the proposed works.
Examples of permitted development
- Small-scale extensions to a house or other residential building, subject to certain size limits and other restrictions, can be enhanced with the use of EWI systems.
- Loft conversions, subject to certain restrictions and requirements for fire safety and access.
- Changes of use from offices to residential properties, subject to certain limitations and conditions.
- The installation of solar panels, satellite dishes, and other minor equipment on the exterior of buildings, subject to certain restrictions and requirements for visual impact.
- The construction of garden buildings, such as sheds and summerhouses, is subject to certain size limits and other requirements for EWI systems.
- The system for installation of external wall insulation to a single house includes prior use of permitted development, such as a rear extension or loft insulation, subject to local council restrictions and approval.
Permitted development rights
It is important to note that permitted development rights are not absolute and are subject to certain limitations and conditions. Local councils may impose additional restrictions on the permitted development system in their areas based on factors such as the size, location, and character of the building or the local area.
In some areas of London permitted development rights may be restricted or removed entirely in order to protect the character and appearance of conservation areas, listed buildings, or other sensitive locations.
It is also important to ensure that any works carried out under permitted development comply with the relevant building regulations, including requirements for fire safety, accessibility, and energy efficiency.
Building regulations are a set of standards that govern the design and construction of buildings. These regulations are in place to ensure that the building system is safe, healthy, and sustainable.
It is also important to remember that permitted development rights are not indefinite, i.e. once the rights have been utilised for permitted minor changes, future minor changes may be subject to planning permission. For example a single house with an added rear extension that was carried out under permitted development may now require planning permission for External wall Insulation
While permitted development can offer a useful way to carry out minor building works and changes of use without the need for planning permission, it is important to ensure that any works are carried out in compliance with the relevant regulations and restrictions set out by local councils.
Types of Properties where external wall insulation may be appropriate
EWI for Traditional build properties:
Traditional properties built typically before the 1930s (and a small proportion later)have solid masonry walls which means cavity wall insulation cannot be used. In the context of construction and architecture, traditional build typically refers to building methods and materials that have been in use for a long time and are characteristic of a particular region.
Most commonly in the UK housing stock and for the purposes of this section of the guide we will mean traditional solid brick built properties, but it is not limited to and can include other materials such as stone and timber frame. Traditional build often refers to older building styles and techniques, which may not meet modern building standards without modification or retrofitting. Many people however, value the aesthetic and historical value of traditional construction and efforts are frequently made to preserve and protect historic buildings and their distinctive features..
Unlike cavity walls for solid brick walls the insulation is applied to the exterior of the walls using appropriate fixings and sometimes adhesives. But traditional build homes may have specific architectural features that make it challenging to apply external wall insulation such as cornices, mouldings or other ornamental details, which when covered can change the characteristics of a building and also pose a challenge in obtaining planning permissions. These features may require careful consideration to ensure they are preserved during the installation process.
EWI for Non-Traditional system build properties:
Non-traditional system build properties refer to housing constructed using non-traditional building methods such as prefabricated panels, concrete or steel. These types of builds were often constructed in the post-World War II period to quickly and affordably address the housing shortage
Many non-traditional system build properties do not have a cavity that can be insulated which means external wall insulation (EWI) is often the most effective way to improve thermal performance and insulate the property. It is however important to note that not all non-traditional builds are suitable for EWI as some may have structural issues or other factors that make installation difficult or impractical.
To determine whether a non-traditional system build is suitable for EWI it is recommended to seek the advice of a qualified EWI installer or the manufacturer. They can assess the building’s condition and make recommendations on the best insulation solutions, which may include EWI or other methods such as internal wall insulation
EWI for Hard to treat cavities (HTTC)
External wall insulation can be suitable for hard to treat cavity walls as it provides a solution for properties that do not have a suitable cavity space for insulation. Hard to treat cavity walls are those that are either too narrow, have obstructions or are filled with rubble making it difficult to install cavity wall insulation. External wall insulation provides a solution for these properties by insulating the external walls and improving the energy efficiency of the property.
It is important to remember that installing external wall insulation on hard to treat cavity walls can be more complex and may require specialist installation. It is also important to ensure that any underlying issues with the walls such as damp or structural problems are addressed before installation to avoid any potential issues down the line
External wall insulation can be a suitable option for hard to treat cavity walls but it is important to consult with a professional installer to determine the best solution for your specific property.
Planning Permission for External Wall Insulation
External solid wall insulation is a type of building work that was granted Permitted Development rights in 2013. It’s important to note that this only applies to single houses and not all homes as highlighted previously. The impact on the character and appearance of the property is also considered, and councils may have specific policies or guidelines in place for this type of work.
Therefore, it’s important to check with the local council before carrying out any building work even if you believe it falls under PD, as there is a good possibility that you may require planning permission for external wall insulation.
PD rights are granted by the General Permitted Development Order (GPDO), but there are limits and conditions that need to be met.
It should be noted to note that PD rights can be removed or restricted for certain properties, such as those in conservation areas or listed buildings. Additionally, some councils have specific policies that restrict PD rights in their area, so it’s always best to check with the local council before carrying out any building work.
The majority of councils have policies that promote energy efficiency, but the benefits of the insulation must be balanced against the impact of the property’s changed character and appearance. This includes not only a change in materials but also a change in the building’s detailing, such as the relationship between the façade, eaves, window reveals, and so on. As a result, both the appearance of the property and locality can be altered, which requires careful consideration.
Properties that will definitely require planning permission for EWI?
- Buildings in conservation areas
- Buildings within the boundary of listed buildings
- Listed buildings*
- Flats and Maisonettes
- Change of appearance post installation (e.g. brick façade being rendered)
*Listed building will also need listed building consent
EWI for buildings in Conservation Areas
External wall insulation is prohibited in Conservation Areas and their curtilage (areas surrounding them) because it has the potential to erode the character and appearance of the area. When considering an application councils will consider whether the insulation will preserve, enhance, or detract from the character and appearance of the conservation area
Most properties in these areas are unlikely to receive planning permission to externally insulate the front facade of the property. However, depending on visibility and architectural features, adding external wall insulation to the side and/or rear elevations may be acceptable. Internal insulation may be possible for walls that cannot be insulated externally, ensuring that important external features on a property are retained.
The combination of External and Internal Wall Insulation is referred to as Hybrid Wall Insulation. These systems should be designed and specified by a manufacturer or a specifier to ensure they meet the correct standards and to avoid issues such as thermal bridging.
EWI for Listed Buildings
If you have a listed building, you will need listed building consent as well as planning permission. We recommend that you seek pre-application advice for either a listed building or a property in a conservation area.
As a rule of thumb listed buildings are historic and have significant characteristics. It is unlikely to be able to replicate some of these characteristics with EWI and planning permission can be very difficult to achieve. In most cases the installation of Internal Wall Insulation (IWI) may be more suitable.
EWI for Non-listed buildings, not in a conservation area (houses only)
In order for permitted development to be considered for these type of buildings the materials used in retrofitting of the existing building must be similar in appearance to those in existence. For example a render finish should be replaced with the same colour render or a brick finish can be replaced by brick slips as a finish.
If the finishing surface of the external solid wall insulation is not deemed to be of a similar appearance to the existing wall, then it may be necessary to apply for full planning permission. But if you are unsure whether the finishing surface will be deemed to be of a similar appearance you can apply for a Certificate of Lawfulness from the local council.
A Certificate of Lawfulness is a formal confirmation from the council that planning permission is not required for a specific type of development. In the case of external solid wall insulation it may confirm that the work falls under Permitted Development and does not require planning permission. This can provide peace of mind for property owners and can also be useful as evidence when selling the property.
It’s important to note that applying for a Certificate of Lawfulness does not guarantee that planning permission is not required, If the council determines that the work does not fall under Permitted Development then full planning permission may still be required. It is always best to check with the local council before carrying out any building work to ensure that the necessary permissions are in place.
Please note this post was created for general guidance purposes only and the final decision rests with the planning department of each council. Please seek the advice of the local planning department.
EWI Planning process – what do you need to do now
To ensure a smooth planning process when considering adding external wall insulation to your property, follow these steps:
- Engage early with the planning department: contact your local planning authority as soon as possible to discuss your project and understand any specific requirements or restrictions
- Seek informal advice: Speak with planning officers informally to get an initial understanding of whether your proposal is likely to require planning permission or not. They can also provide guidance on any potential issues that may arise during the formal application process
- Seek pre-application advice: Many local planning authorities offer a pre-application advice service, which can provide detailed feedback on your specific proposal before you submit a formal application. This can help you address any concerns and improve your chances of obtaining permission.
- Apply for a Certificate of Lawfulness: If you want to be certain that your proposal does not require planning permission, apply for a Certificate of Lawfulness from the planning authority. This legally confirms that your project is considered permitted development and can proceed without formal permission.
- Apply for planning permission: If your project does require planning permission, submit a formal external wall insulation planning application to the planning authority. Ensure you provide all required documentation and pay the appropriate fees.
- Apply for Listed Building Consent: If your property is a listed building or located in a conservation area, you may need to apply for Listed Building Consent in addition to planning permission. This is required for any works that might alter the character or appearance of the property.
By engaging with the planning department early and seeking appropriate advice, you can navigate the planning process more efficiently and minimise the risk of delays or refusals
Below is a list of planning departments in London and a link to their websites
Understanding the Costs Associated with EWI and Planning Permission”
When considering an External Wall Insulation (EWI) system, it’s crucial to understand the associated costs. The total cost of an EWI system can vary significantly depending on the size of your property, the type of insulation used, and the system manufacturer. However, it’s not just the cost of the EWI system itself that needs to be considered.
If your property is in a conservation area, areas of outstanding natural beauty or is a listed building, you may need to apply for planning permission before installing an EWI system. The cost of planning permission can vary depending on your local authority, but it’s an essential factor to consider in your budget.
Additionally, you may also need to factor in the cost of obtaining an Energy Performance Certificate (EPC) if you don’t already have one. An EPC gives your property an energy efficiency rating from A (most efficient) to G (least efficient) and is required when selling or renting out a property.The Impact of EWI on Energy Performance Ratings and EPCs
Installing an EWI system can significantly improve your property’s energy efficiency, which can be reflected in its Energy Performance Rating. This rating is part of the Energy Performance Certificate (EPC) that assesses how energy-efficient your home is.
A higher Energy Performance Rating not only means lower energy bills but can also increase the value of your property. It’s worth noting that the cost of improving your property’s energy efficiency through an EWI system can often be offset by the savings made on energy bills over time.
Remember, it’s essential to choose a reputable EWI system manufacturer to ensure the quality and effectiveness of the insulation. While this may involve a higher initial cost, the long-term benefits in terms of energy savings and improved property value can make it a worthwhile investment.