Conservation Areas 101

What is a conservation area, and how does it affect me?

What is a Conservation Area?

An area is designated as a conservation area for many of the same reasons that an individual building is listed. It acts as a sort-of 'blanket' listing which places extra planning control on every building within the conservation area, and even those which can be seen from the conservation area. This is important as even buildings which don't look particularly old, if within the conservation area, will still be subject to this extra planning control. What this all means in practice is that anything that materially alters the appearance or character of a conservation area requires planning permission.

The general rule of thumb is that if a building is in a conservation area, its exterior cannot be altered without permission. If a building is also listed, neither its exterior nor its interior can be altered without permission. Whilst this is a vast oversimplification and there are many subtleties and variations, it is a useful principle to bear in mind in the first instance.

What is the BCAAC?

Conservation areas often come with a 'CAAC' - a Conservation Area Advisory Committee. This is formed from members of the community that live and/or work in the conservation area, who may themselves be involved in planning or architecture. Their role is to inspect planning applications in their conservation area and comment on them to aid Camden's planning officers, and also to spread awareness and appreciation of their conservation area. Broadly speaking, a CAAC's role is to protect its conservation area.

We are the BCAAC - the Bloomsbury Conservation Area Advisory Committee - and we are slightly different in that we cover multiple conservation areas which we refer to as the Bloomsbury Conservation Areas. An overview of our conservation areas can be found here.

Read on to find out more about listed buildings, conservation areas, and how this affects what works can be carried out to property.

Listed Buildings

Before making any changes you should first check whether your property is listed. If it is listed (usually Grade II) then you need to be aware of the obligations placed upon you as a property owner. Particularly you are liable for any illegal alterations (alterations made without planning approval) even if they were carried out before you became the property owner. This rather stringent obligation ensures that owners do not make illegal changes behind closed doors and then claim that it was the action of a previous owner. It is therefore also important that you make sure when buying a listed property that no illegal changes have been made, as you may be ordered to reverse the changes or even be guilty of an offence.

Furthermore, you cannot use ignorance as a defense - for example you cannot make changes but claim that you didn't know the building was listed or that permission would be required. Thus it is especially important to ensure that you are familiar with the listing of your building and what that entails.

If your building is listed, you should check its listing description on Historic England’s website. It will usually describe the important features of the building – its architectural and historic interest. However, it is very important to note that, once a building is listed, any alterations, internal or external will need consent whether or not you personally consider them relevant to the reason for listing. Very wisely Historic England does not leave it up to owners to make the decision as to the importance of a feature. Alterations simply cannot be made without listed building consent. If you do make alterations you may be found guilty of a breach as any removal or demolition of original fabric or features is a criminal offence. This does not just pertain to physical ‘features’ such as old mouldings and fireplaces – but can be more wide-ranging and subtle such as the type of use of a room. Carrying out routine maintenance works does not generally require permission, and redecoration is generally permitted so long as no material alterations are made.

For any significant changes to a listed building - even those which aim to 'restore' historic features or use, permission must be sought from the local authority. For some important cases we also offer a site visit as part of the consultation exercise.

More information on alterations to listed buildings can be found here, on Historic England's website.

Non-listed Buildings

Alterations to non-listed buildings within a conservation area still require careful consideration. This is especially so in our conservation areas which are generally considered 'of national importance' which means they are particularly significant.

The interior of a building within a conservation area can be altered generally at will, although we would still advise you to take care to avoid irreversible changes if possible. This is because the interior does not contribute to the appearance of the conservation area, as it cannot be seen from the outside. The exterior however cannot generally be altered without planning consent from Camden, as it does contribute to the conservation area's appearance.

General maintenance can take place to the exterior without consent - for example repainting of a wall, railings, or front door if the colours chosen are similar to the existing or take precedent from the local area. For example railings and ironwork are almost exclusively painted in black or dark gloss, whereas window frames and doors are painted in a variety of colours but generally from a restrained muted palette. You are safest simply to imitate colours from the surrounding buildings or similar era buildings from around Bloomsbury and London - and this is best practice for any form of alteration. If you choose to paint a Georgian front door in neon green for example, you are likely to upset neighbours and perhaps face enforcement action from Camden.

You should also keep in mind the question "Are the changes that I'm making reversible?". It is not so serious of an offence if a door is painted in bright pink because it can easily be painted over. However if you were to paint an exterior brick wall which had not already been painted, the brickwork would become permanently damaged - and so the change will have been irreversible, and it is therefore generally not permitted to paint brickwork in this way.

In all alterations in our conservation areas, you should keep in mind that although a property may belong to you for the moment, the heritage and history of the property belong to everyone, and it is your duty to preserve that heritage for future generations. Irreversible changes erase heritage permanently, and so irreversible changes of any type to historic buildings should always be avoided.

Do I need Permission to replace my Windows?

Given the noise and pollution of Central London, many property owners are keen to replace historic single glazed windows with double or even triple glazed windows. If your windows are historic, making such alterations to them is generally illegal without planning permission. This is because all windows can be seen from the outside, and so alteration to them affects the appearance and character of the conservation area. If your windows are 'sash-windows' (vertical 'sliding' windows) this is a sure sign that they cannot be replaced. Another easy way to test whether your windows are historic is to see if there is a 'ripple' in the glass. Historic glass is usually rippled due to historic methods of manufacturing, whereas modern glass is perfectly smooth. In some cases bomb-damaged glass has been replaced with poor quality rippled glass and this is itself an interesting feature worth preserving.

The historic ripple effect in glass is an important reason why even like-for-like replacements can be illegal. To the trained eye, the difference between historic and modern glass is very noticeable, and so making such a replacement can be deemed to have negatively affected the appearance of the conservation area - even if that change in appearance is not noticeable to you. This is why you should exercise extreme caution in making any changes that affect the exterior of a building, even if to your eye it appears that nobody will notice.

We also have a number of interesting and sometimes listed more modern buildings in our Conservation Areas, for example the Brunswick Centre. Such buildings would also be affected by inappropriate replacement of windows, which is another reason why there is a blanket condition that permission should be sought for any replacement of windows in the Conservation Areas.

In a conservation area the best alternative to double glazing is secondary glazing. This is when a second set of windows are installed inside the building, with a substantial gap between the old and new windows. This method is generally cheaper, more energy efficient, and far better in reducing noise. It is of course advantageous as the historic windows are preserved without any change to the external appearance of the building, (although the character may be altered), and planning permission is not generally required. In a listed building, it is a question whether the character of the interior is negatively affected, and so advice should be sought and permission will generally be necessary.

It is generally assumed by the public that double glazed PVC casement windows are 'the way to go' when possible, with a large variety available on the market. It is also generally believed that such windows are energy efficient, helping to 'save the planet' by reducing energy bills and therefore reduce the burning of fossil fuels. Living in a conservation area is sometimes seen as an irritating impediment to this 'sensible' alternative. However these PVC windows are actually far less sustainable as they require the removal and disposal of windows made from sustainably sourced and recyclable materials, and replacement with non-recyclable and unsustainable plastic windows. The general belief that such PVC windows are eco-friendly is a result of the extremely successful but misleading advertisement campaigns of companies selling such windows (just question where you learnt that double glazing is eco-friendly - was it from a company advertising double-glazing?). Secondary glazing, although not as well known or advertised, is far more sustainable and appropriate for any building, but especially for buildings in a conservation area.


The special character of Central London arises generally from its well-preserved architecture which gives a window into the special historic interest of the area. This history of special interest in our case is generally 'pre-war', and the further that one goes back the more significant that this history becomes. The way that services were historically displayed forms a part of the special character of the area - for example historic gutters and downpipes, along with chimneys are often interesting and positive contributors to the appearance of the area, giving a window into London's history. However modern services do not form a part of the history of most buildings, and when visible do not make a positive contribution to the appearance and character of the area. The general principle is that any 'modern' servicing - such as cables, aerials, or air-conditioning units should be hidden from public view, and in particular they should not be visible from the street.

When new cables are installed by cable companies every effort should be taken to ensure that they are hidden from view. This can sometimes be difficult as cable companies can often be obstructive and focus simply on the quickest and easiest route for their cabling, but quoting the fact that you are in a conservation area should be enough. Cables should enter the building at ground floor and then distribute throughout the building on the interior, rather than scaling the exterior and entering at different points. This is to ensure that the appearance of the conservation areas is preserved. Cables which dangle in front of a façade detract from the appearance of any area, and so should especially be avoided in a conservation area whose appearance it is desirable to preserve.


It is unfortunately common that individual businesses assume that shopfronts can be changed at will and without permission.

Any alteration to a shopfront which materially alters its appearance requires planning permission.

It is unfortunately also common that shop-owners decide to bypass the applications system, either without making any application or after receiving a rejection, in the hope that nobody will notice the changes. If you are thinking of doing this, you should think again. Changes without permission are an offence and legal action can be taken retrospectively up to a limit of five years after the offence. With the advent of Google StreetView and access to its historical records (updated at least annually in Central London) it is easier than ever to detect and date illegal changes. We can and do notice illegal alterations and work with Camden to crack down on infringements.

General maintenance to shopfronts does not require permission - so that repainting or replacement of broken glass for example is permitted.

For those unsure about how to design their shopfronts to accord with the conservation area, we recommend working with a qualified architect with experience of Conservation Areas. We are also working on a guide to designing acceptable shopfronts.

Still Uncertain?

If you are still uncertain about whether the changes you are making are permitted, Camden's officers will give the final say. It is better to be certain before making changes rather than be hit with an enforcement notice, perhaps even years in the future.

The applications section of our website sets out how we are likely to view different types of applications.