Conservatories on listed buildings

Conservatories on Listed Buildings

Conservatories on listed buildings

Adding a conservatory to a listed building requires listed consent.  Burberry Harris Moon have a wide experience in successfully negotiating listed consent and planning permissions.  Over one third of our projects include buildings with listed status or that are in a conservation area.

I would like a conservatory on my listed house, is listed consent likely?

Clearly any application for a conservatory extension will be considered on its own merit, with regard to the particular characteristics for the individual site.  The key is a conservatory design that complements, not dominates the existing house, matches some of the existing features and uses quality traditional materials.  In many cases, yes, a conservatory is possible on a listed building.

Beware of the standard ‘Edwardian conservatory’ design

Since the rapid growth of the conservatory market from about the 1980’s, the ‘Edwardian’ or ‘Victorian’ conservatory has been at the heart of the conservatory market.  Even at the quality end, there has been a preponderance of ‘traditional designs’ which may appear very ornate or fussy.  Non authentic cresting, finials or dentil mouldings are commonly added features.

On Georgian or early mid 19th Century houses these styles are likely to clash with the rather plain and restrained appearance of rear elevations.  It is better to reflect existing character by simplifying the design.

Usually a square or rectangular conservatory shape is chosen.  Simple roof designs work best; consider the classic lean-to or gable end design.  Use simple, neatly dressed lead for ridges.  Roof capping bars are best painted a dark lead grey.

Always maintain the same brickwork for dwarf walls, including plinth brick details, brick colour and pattern.

Replicating some of the house window design details in the conservatory joinery often helps to harmonise the conservatory with the house.  Be careful where the house windows have small Georgian lights or leaded lights.  A conservatory with Georgian glazing bars forming small lights can feel like being in a birdcage!  Consider dividing the conservatory windows into a crucifix glazing bar design, even if this means each pane of glass is quite large.  Otherwise, consider just having glazing bar detailing in fanlights only.

Conservatory design considerations for listed buildings

Size design and form

No extension should dominate the existing house in size or shape.  Conservatories should generally be subservient, appearing as if they have a ‘supporting role’ to the existing house.

Plot coverage

The extent that the original plot is taken up by an extension can have an impact upon the character of the area.

Character of the area

The conservatory must be appropriate for the area.  It should not be overly prominent in the street scene through being too large or of uncharacteristic form.  This is of particular concern where a conservatory is proposed to the side of a property.

Character of the house

Conservatory extensions must be in keeping with the character of the building, and they must not upset the balance of the original design.

A conservatory extension should be ‘additive’

Listed buildings may be many hundreds of years old.  Owners of listed buildings are in one sense a ‘custodian’ of a building for a short period of its history.  A listed property may have been extended or substantially altered in its life, metamorphosing from the initial structure to its current form.

A conservatory extension should therefore be an addition to this process.  A conservation office may take the view that to be ‘additive’ a conservatory extension needs to be designed in a style which is contemporary to the period in which it is added.  This may mean using traditional materials used in a contemporary style, or it could mean a wholly modern approach using the latest materials.


The colour of a conservatory extension will be an important contributor to local character and distinctiveness.  Do not assume you should match the colour of the windows, especially if these are white.  Stand back from the house and consider the dominant colours.  For example, a house clad with clay peg tiles and covered with wisteria will have strong natural tones of orange/red, grey and green.  For this situation consider darker colours in the green/grey range.  The finished conservatory in a dark tone will act as a foil for its surroundings and allow the strong house colours to dominate.

Double glazing

Double glazing will normally be allowed on a conservatory extension fitted to a listed property.  Certainly a conservatory without double glazing would not make a very liveable space.  Of course, double glazing is unlikely to be allowed for replacement windows in any part of the existing house.  For these, specialist solutions will be required, slimlite double glazing for example, which will fit into traditional delicate glazing bar sections.

What is required?

For a listed building, a conservatory will require listed building consent.  If planned works go beyond permitted limits a full planning application with listed consent is required.

Note:  If listed consent and planning permission are both required, a combined application can be made.

Examples of conservatories on listed buildings

Here is a conservatory added to a listed cottage in the heart of Sussex.  The conservatory has a large opening through to the lounge, thus transforming a small gloomy room into a light and spacious living area.

Conservatories on Listed Buildings

Conservatories on listed buildings

This conservatory has been carefully designed to match the host building which is a Grade Two listed property.  It features a pitched roof design with a gable front above French doors.

Conservatories on Listed Buildings

Conservatories on listed buildings

This property is a Grade Two * listed building in west Kent.  It is an 18th century detached cottage and the conservatory is made in European oak.  This features double glazed windows which include a Georgian lead detail.

Conservatories on listed buildings

Conservatories on listed buildings

Listed buildings and building regulations

Conservatories on listed buildings may be exempt from building regulations, the criteria is the same whether listed or not (generally: less than thirty square meters, minimum 75% roof glazing, external quality doors separating the conservatory from the house).

Exemptions from part L of the building regulations

Listed buildings may be exempt from the energy efficiency requirements of the building regulations ‘where compliance with the energy efficiency requirements would unacceptably alter their appearance or character’.

In practical terms, this usually means that if replacing windows in a listed property, the new windows will need to match the originals and therefore be made with the same delicate glazing bars and single glazing of the original.  (See information on slimlite glazing).

However, most conservation offices will accept double glazing to be included in conservatory extensions provided the design is appropriate.


VAT rules for conservatories on listed buildings

New rules for October 2012

Sadly, since the 1st October 2012, all alterations on listed buildings are now charged at the current rate of VAT.  This applies to both alterations and repairs.

This a great shame, as owners of listed buildings play an important role in preserving our heritage.  Satisfying the requirements of a conservation officer when repairing or altering a listed property always means traditional materials and methods must be used, and these can of course be expensive.