Una Kaya is a London-based architect who works closely with The Soundproof Windows, helping clients who live in a conservation area to get their proposals past the planning authorities. If you require help or advice on a project, please do get in touch with Una Kaya.

Read on for more information about making changes to a property in a conservation area – however, Una does stress that all architectural work is done on a case-by-case basis, and therefore there are no general rules that can be applied across the board. It is important to understand that each project is judged independently, and that they are also judged by independent planning authorities that use differing rules and criteria.

Q: Tell me a bit about yourself - where you studied, what your specialism is within Architecture / What is your interest in/route into conservation areas?

With 10 years of study under my belt – including two undergrad certificates and 2 post-grad certificates – architecture is an essential part of my world. I see through the lens of architecture, always looking for historical layers, aesthetics, engineering and materials, texture and meaning.

I have set up as a sole practitioner based in Greenwich – where almost every building is included in a conservation area – though history is everywhere in this city – of course in the listed buildings and conservation areas – but in almost every building in London. I have a keen interest in architectural history and a RIBA qualification in conservation.

Q: What is a conservation area, and what is the aim of a conservation area?

A conservation area is decided by the planning authorities in the local area. In London, conservation areas are nominated and designated by the individual boroughs. Their mission is to conserve the areas and buildings that are deemed to be ‘special’ – whether that is due to their architecture, their history, or for another reason.

Certain rules are applied to buildings in a conservation area, which are enforced in order to preserve certain characteristics that are particular to the building and/or area.

Q: When making changes to a property in a conservation area, what planning and considerations are always necessary?

Doing work on a building of any type – conservation, listed or not – work should always be in consideration of what is already there, working to keep the original character, features, proportions and materials. However, in a conservation area, planned work and proposals must be harmonious with the existing features.

Some properties/conservation areas require the architect to create a pastiche – an exact replica of the original – whereas, other conservation areas might accept a proposal that in-keeping with the original whilst using updated technologies, materials and design features.

The planning authorities within a conservation area look for additions and changes that empower the original structure, and will not permit changes that they believe will degrade, remove or take away from it. In other words, the work that you do should not constitute an overall ‘loss’ for the building, and so where possible, historic or original features and materials should be kept and restored, rather than removed and replaced. Conservation areas tend to prefer proposals for restoration, as there is no loss of material (i.e. the exact type of wood used in the sash window), though in cases where repair and restoration are not possible, then the planning authority will look for replacements that share the exact characteristics of the original.

Q: What are the main considerations when changing the windows in a property in a conservation area?

When it comes to upgrading the windows in a conservation area, it is very unlikely that the planning authorities will allow an original single-pane sash window to be replaced with a double-glazed UPVC casement window, because that is a considerable loss to the building and to the conservation area as a whole. However – depending on the planning authority in question – it may be permissible to replace a single-glazed sash window with a double-glazed sash window, if the frame/structure is sufficiently similar to the existing design.

Swapping to a new material – UPVC for example – may be permitted in some cases, however, the swap must be justified, and will only be permitted if it is seen to benefit the building in the long run. Clients looking to replace old and often inefficient windows are often keen to install windows that use hi-tech materials, but in a conservation area, this should always be done in cooperation with the planning authorities to ensure that the work is permitted.

Q: How does the Architect help when making changes to a property in a conservation area?

When doing work in a conservation area, the focus must be on quality and historical accuracy – changes cannot be made for profit-making reasons alone, i.e. replacing original wooden-framed sash windows with a cheap UPVC casement window. An architect will be able to guide the home-owner on the most appropriate materials, designs and contractors.

A good architect would never suggest stripping character and features from a property. Luckily, at the moment, there is a trend for restoring old features and using historic materials, however, like all trends – this will come to an end.

Having an architect as part of your project ensures that the building is treated with respect, as well as bringing invaluable expertise when it comes to handling the planning authorities.

Crucially, when making big changes to a property, such as replacing the windows, an architect can predict the knock-on effects of each decision. For example, installing double-glazed UPVC windows in place of wooden-framed single-glazed sash windows will change the moisture level in the building, an issue that should be addressed in order to prevent other issues occurring, such as damp, mould and mildew. An architect or good builder understands how a building functions, and can advise on the best (and in the long-run, cheapest) option.

Q: What other advice is useful for people making changes to a property in a conservation area?

By showing a keen interest in your property and the conservation area, the home-owner will learn about the building they live in, understanding why it was built, how it was developed, and more about its history. This is a great way to connect with the idea of preserving and maintaining a building, enabling the home-owner to make better decisions about their property.

Q: What are the differences between making changes to a flat or house in a conservation area?

Every property comes with ‘permitted development rights’, and even properties in a conservation area have some freedom when it comes to making certain changes without requesting permission. A house comes with a set permitted development rights which allow the owner to change features ‘like-for-like’, whereas a flat does not.

Flat owners do not have any right to change, even like-for-like, and so permission must always be sought when making changes to a flat.

Q: What are the most common mistakes, traps and pitfalls when working on a property in a conservation area?

The biggest and most costly mistakes are often caused by ignorance; if the home-owner does not know which changes require planning permission, then they are very likely to run into trouble – particularly if they are in a conservation area. The worst case scenario is that the planning authorities deem the work to be bad or not in-keeping with the original, and the home-owner is required to undo the work and return the property to its original state. This is done at the home-owners cost, and it can be an extremely expensive process.

Another unpleasant option is that the planners do not like the changes, and they require you to apply for permission retrospectively.

It is worth noting that it is always more expensive to fix bad work than it is to do things the right way the first time. Often when working with historic buildings, nothing is quite as it seems and there are surprises and unknown factors that present themselves along the way, which is the reason that it is advisable to have an architect on board for all projects in a conservation area.

Q: What role does the architect play in the process of making changes?

The architect has many roles, but they take overall responsibility for the project. The architect can advise but they cannot enforce their opinion on the client – the job of the architect is to listen to the client’s brief, and to design a project that is to the client’s best interests, whilst also considering the best interests of the building, the area, the local history and the planning authorities.

In the majority of cases, the architects fees are more than covered by the savings that they create on a project, and there are architects of all types and for all budgets.

Q: Does the architect help with the planning and permissions?

The architect will complete the planning and permissions, and in many cases, they will have existing relationships with the relevant people within the council/planning department. Whilst these existing relationships cannot sway the final judgement, an architect who provides good drawings and a clear plan for the proposed work is able to help the decision-makers to make a fair judgement.

Applying for permission from the planning authorities is extremely complicated and detail-oriented, and a qualified architect is able to provide all of the necessary information. For example, when working with The Soundproof Windows, I work closely with Seb (the builder and experienced engineer), as well as a team of other professionals, including surveyors and contractors, in order to provide the planning authorities with the level of detail that they require.

Essentially, the architect will provide the conservation officers with a clear and detailed package that fully explains the project, creating an application that is a clear and persuasive argument for the proposed work.

Q: What should clients look for in an architect?

All RIBA chartered architects have sufficient experience, as well as having indemnity insurance, which is vital in insurance claims relating to the work that is done to a property (work is covered for a 6-year period). A good architect will also suggest using contractors who also have indemnity insurance, and so if any issues arise further down the line, the client’s insurer can make a claim on the architect/builder/structural engineer’s indemnity insurance.

An architect also takes the role of ‘contract administrator’ – creating a comprehensive contract for the project, including a schedule as well as the different contractors. This contract is vital in completing the project, and it is also essential if an insurance claim is made, as it is not possible to make a claim without a proper contract.


All of our soundproof windows come with a 10 year insurance-backed guarantee. Safeguarded against swelling and disease, they’re built just for you.



We know how important your home is to you. That’s why we pride ourselves on offering advice that helps you make intelligent, informed decisions concerning changes to your property. Want to ask us any questions?



All of our products come with up to a 10 Year Insurance Backed Guarantee provided by the Consumer Protection Association. So you can rest assured that your home is in safe hands.



We have been Trading Standards Approved and are proud to be enrolled on the Buy With Confidence Scheme, ensuring customers just like you have their interests protected.

tsw_footer_tm mobile


Consumers can feel confident using a TrustMark registered business, as the government-endorsed scheme ensures high quality service and a range of consumer protection options.



The Soundproof Windows was announced as the ‘Leading Provider of Acoustic Windows & Doors 2020’ and the winner of ‘Best Acoustic Window & Door Installation Service 2021’ at the SME News Awards.