Renovating a listed building is no small feat, especially in London where historic architecture is part of the city’s identity. While these projects can be incredibly rewarding, they also come with unique challenges. Whether you’re planning an extension, a conversion, or a full-scale refurbishment, understanding the complexities of listed building consent, listed building planning permission, and the regulations surrounding listed building extensions is essential. In this guide, we’ll walk you through the process, offering practical tips and showcasing how DeVis Architecture can help you turn your vision into reality.
A listed building is one officially recognised as being of historical or architectural significance. These properties are protected under the Planning (Listed Buildings and Conservation Areas) Act 1990 to ensure their character and heritage are preserved for future generations.
Listed buildings fall into three categories:
If your home is listed, any modifications – from replacing a window to adding an extension – will require listed building consent. Failure to comply can lead to severe penalties, including fines or even undoing unauthorised works.
Contemporary Conservation Area Extensions – Copper House
Unlike regular planning permission, listed building consent is specific to alterations that affect the building’s character. This applies not only to external changes like extensions but also to internal modifications, such as removing walls or updating fixtures.
When applying for listed building consent, local planning authorities (LPAs) consider:
For example, replacing a timber sash window with a modern uPVC version would likely be rejected, as it undermines the building’s authenticity.
Traditional Conservation Area Wraparound Extension – Walnut House
In most cases, you’ll need both listed building consent and standard planning permission for extensions or significant works. The process involves submitting detailed plans to your local council, including:
At DeVis Architecture, we excel in crafting plans that meet these stringent requirements while maximising your property’s potential. Our experience with listed building extensions ensures we strike the perfect balance between modern functionality and historical integrity.
Planning authorities often insist on using traditional materials and techniques, which can drive up costs. For example, extending a Georgian terrace in London might require handmade bricks and lime mortar to match the original construction.
Extensions must complement the existing structure rather than overshadow it. This means a modern glass box extension might not get the green light, but a discreet rear extension with period-appropriate features could.
Many listed buildings in London are also in conservation areas, adding another layer of regulations. In these cases, external changes that affect the area’s overall appearance will be scrutinised even further. Check if you are in a conservation area using our expert guide!
Contemporary Extension & Basement in a Conservation Area – Monument House
Working with professionals experienced in listed buildings is non-negotiable. At DeVis Architecture, we work with expert heritage consultants who can guide you through the entire process, from initial designs to securing approval.
Researching your building’s historical significance can help you create a proposal that’s more likely to be approved. For example, if your property once had a particular architectural feature (like a garden room), restoring it as part of your extension could appeal to planners.
Engage your local council’s conservation officer early to discuss your plans. Their feedback can help you refine your design and avoid costly delays.
Where possible, the LPA particularly appreciates incorporating original materials or high-quality replicas. This also ensures your extension feels like a natural evolution of the building rather than an afterthought.
The process can be lengthy, with planning applications often taking 8–12 weeks or longer if revisions or further reports/investigations are needed. Keep an open mind and be prepared to adapt your plans to align with heritage requirements. Listed properties may not be ideal if you are a developer looking for a quick exit strategy.
These are among the most common types of extensions for listed properties. Discreet rear additions such as a 3 meter house extension can offer extra living space without impacting the street-facing façade. Design elements such as in-keeping roof designs, timber-framed windows, and matching brickwork are often required. It is key to have a good idea of the house extension materials you are looking for before discussing with your design team.
Expanding downward is a popular option in London, particularly for Georgian and Victorian home extensions where there is limited outdoor space. However, basements in listed buildings can be complex cases due to concerns about structural integrity, services and drainage.
Glass connectors are a clever way to integrate modern home design ideas with historical structures. They preserve the original building’s character while adding a contemporary flair, and we find that local councils tend to prefer this option.
Loft conversions in listed buildings are subject to strict regulations, as permitted development cannot be utilised for typical dormer loft conversions or L-shaped loft conversions. Externally, dormer windows must blend seamlessly with the existing roof, while internally, historic beams or trusses may need to be retained, potentially disrupting your proposed new space.
Conservation Area House Extension Plans – Monument House
One of our previous projects involved extending a Grade II listed property in London. The homeowners wanted to create an open-plan kitchen at the rear by means of a single storey rear extension. We worked closely with the local conservation officer and heritage consultant to design a single-storey extension that complemented the property’s Georgian aesthetic.
Key challenges included:
The result was a seamless blend of old and new, providing the homeowners with a modern space that respects the building’s history.
Sleek Conservation Area Extension Design – Stage House
Extending a listed building is often more expensive than extending a standard property due to:
In London, you can expect to pay £2,500–£4,500 per square metre for a listed building extension, depending on complexity. For more details on costs take a look at our other blog on House Extension Costs for 2025!
Renovating a listed building without obtaining the proper listed building consent or planning permission can have serious consequences, both legally and financially. Whilst it is possible to achieve retrospective planning permission, it cannot be guaranteed, so it’s advisable to go through the process beforehand. Listed buildings are protected to preserve their unique historical and architectural value, so any unauthorised changes – no matter how small – can lead to enforcement action.
If you carry out work without consent, your local planning authority (LPA) could issue an enforcement notice requiring you to undo the changes. Restoring the building to its original condition can be extremely costly, especially if it involves removing modern materials and replacing them with heritage-approved ones. On top of that, you could face hefty fines or even prosecution, as unauthorised works to a listed building are treated as a criminal offence.
Unauthorised changes can make it difficult to sell later on, and may also affect your property’s market value. Buyers and lenders may steer clear of a property with unresolved planning issues, fearing the potential costs of putting things right. Even if the changes seem minor, they can make selling the property more difficult and potentially lower its value instead of adding value.
Listed buildings have unique character and heritage that unauthorised works can damage or erase. For example, swapping out traditional timber windows for modern uPVC ones might seem like a practical choice but could harm the building’s aesthetic and historical significance.
Working with experts is key. At DeVis Architecture, we guide you through the planning process, liaising with conservation officers to ensure your project meets all the necessary requirements. With our help, you can achieve your dream renovation while preserving your property’s charm and avoiding unnecessary headaches.
Building Control requirements can be strict, but listed buildings often benefit from certain exceptions. Since these properties are legally protected under the Planning (Listed Buildings and Conservation Areas) Act 1990, preserving their historical character takes priority. For example, modern insulation standards of the current approved documents might be relaxed if they would compromise original features like timber-framed windows or decorative plasterwork.
These exceptions ensure that the building’s heritage isn’t lost to meet contemporary regulations. However, it’s not as simple as a free pass; you’ll still need to demonstrate with building regulations drawings that alternative solutions maintain safety and functionality. For instance, fire safety measures might be adapted to suit the building’s unique layout.
At DeVis Architecture, we specialise in creating bespoke designs for London’s most characterful homes. Our team has extensive experience navigating the challenges of listed building planning permission and listed building consent, ensuring your project runs smoothly from start to finish.
We pride ourselves on blending contemporary living with architectural heritage, delivering solutions that respect the past while embracing the future. Whether you’re planning a modest single storey rear extension or a complete home renovation, our tailored approach ensures your home’s unique character shines through.
Meet the Founders, Zak & Lina – DeVis Architecture
Renovating a listed building is a unique journey, combining creativity, patience, and an appreciation for history. By understanding the complexities of listed building consent, planning ahead, and partnering with the right experts, you can create a stunning space that balances modern functionality with timeless charm.
At DeVis Architecture, we’re here to make that journey as seamless as possible. If you’re considering a listed building extension or refurbishment in 2025, get in touch to discuss how we can help bring your vision to life.
One of our team will get back to you as soon as possible.