Loft conversions - Policy Guidelines

6. Loft conversions

Many properties on the Dulwich Estate have lofts with the potential for use as additional living space. Roof lights or dormer windows are required to provide natural light and these changes to the external appearance of the building require approval under the Scheme of Management:

The Scheme of Management requires that no material alteration is to be made to the external appearance of any building or structure on an enfranchised property and no new or additional building or structure is to be erected without the prior written approval of the Managers.

The Managers of the Scheme are the Incorporated Trustees of The Dulwich Estate and written approval for alterations is provided to applicants by way of a Licence.

Loft conversions are subject, in addition to Scheme of Management approval, to a variety of rules and regulations and it is essential to seek expert professional advice. Structural considerations, access, means of escape, thermal insulation and other issues are subject to the building regulations and require approval from the local authority. Planning permission may also be required.
Applicants will be required to indicate the name of the individual who is to supervise the works.

General

The proposals for a loft conversion should be in keeping with the original design of the property and where appropriate, to the group of properties in the vicinity.

Roof extensions and proposals to change the profile of the roof are unlikely to be approved. Mansard roofs will generally not be approved. If the original loft does not provide adequate space for the proposed use, it is unlikely that a loft conversion is feasible.

Dormer windows

Traditional dormer windows do not dominate the roof; as a general rule, the width of the dormer should not exceed half the width of the roof and the height of the dormer should not exceed half the height from eaves to ridge.

Loft conversions - Dormer windows illustration 1

In order to ensure that the loft conversion does not spoil the character of an individual house and/or groups of houses, the design of the dormer window should comply with the following:

Located at the rear and not, generally, at the front or side of the property.
The size should be in proportion to the size of the roof and should complement the style and period of the property.
On properties with back additions, the dormer should be no higher than the ridge of the back addition roof. Party walls should not be raised, the sills should not be built upward from the gutter line or from the walls of the property.
No form of balcony or external terrace should be provided.

Loft conversions - Dormer windows illustration 2

Drawings in support of the application are to include construction detail at a scale of not less than 1:20 and are to accurately show the front and side elevations, and a section through the dormer including the internal floor level. The Managers reserve the right to request additional design drawings at such scale as is necessary to fully understand all design and construction details. The dormer window must be constructed in accordance with the detailed drawings attached to the Licence approving the works.
The materials for the window and cladding are to be specified. Cladding materials should match or complement the existing roofing (see also Guidelines For External Repairs And Redecoration, Replacement of Roofs, Chimneys and Repointing ).

Roof lights

Small roof lights are a feature of many traditional houses on the Dulwich Estate, often providing natural light to stairs and landings. These traditional roof lights have a slender cast iron frame set into the roof tiles. Copies of this style of roof light are now marketed as ‘Conservation Roof Lights’.

Modern roof lights have more conspicuous frames and flashings and stand proud of the roof finish. These are available in a range of sizes and the larger lights can be visually obtrusive.

Applications for roof lights should comply with the following:

New roof lights in the front roof of a property are unlikely to be approved. Where an original roof light in the front roof of the property is to be replaced, this does not require a licence providing that this is a Conservation Roof light of the same size and fitting in the exact same location.
Small roof lights may be acceptable at the side of the house. Where the location is conspicuous from the road, a Conservation Roof Light should be specified.
Roof lights at the rear of the property will be approved providing that they do not dominate the roof.
Roof lights which open to form a balcony will not be approved.

Traditional Dormer Windows

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Please also refer to the General Guidance Notes For Freeholders Of Property Subject To The Scheme of Management Making Application For Building Or Tree Works.

March 2004

Documents

Loft Conversion Guidance Notes (PDF 3909kb)