3.12  The NPPF sets out that the essential characteristics of the Green Belt are its openness and permanence. Policy RE2 of Local Plan Part 1, in accordance with national policy, sets out that most forms of development in the Green Belt will be inappropriate other than in very special circumstances. The NPPF sets out a number of exceptions to this, including extensions provided they are not disproportionate, replacement buildings provided they are not materially larger, and limited infilling within villages. A number of other forms of development are also potentially appropriate provided they do not harm the openness of the Green Belt. These are set out in the NPPF.

3.13  The NPPF does not define 'disproportionate,' 'materially larger,' or 'limited infilling' in relation to development within the Green Belt. As such, in order to provide clarity to residents and developers, Policy DM14 below is proposed to set out in greater detail how residential applications in the Green Belt will be assessed.

3.14  A visual test is used to assess whether extensions, alterations, and replacement dwellings are acceptable within settlements. Outside of defined rural settlements, a percentage guideline is also used in the assessment of proposals.

3.15  The Council has decided to keep the current base date of 31st December 1968 to define the original dwelling for the purpose of assessing extensions. This date relates to when Surrey County Council first adopted a policy to control the scale of extensions to dwellings in the countryside and as such is consistent with the concept of permanence, as essential characteristic of Green Belt.

Explanatory notes:

3.16  The percentage guidelines which apply to extensions and replacement residential buildings are intended to support the openness and permanence of the Green Belt, which are its essential characteristics. Each application will, however, have to be considered on its own merits, taking into account factors such as how isolated a site is, and the scale and mass of the original building. Developments which exceed these guidelines may be acceptable in some circumstances. Where a building is outside of but visually well related, to the settlement boundary, the Council will decide on a case-by-case basis whether it is appropriate to apply the percentage guidelines.

3.17  Determining whether a site is within a village will involve consideration of the settlement boundary, and whether the site forms a part of the village.

3.18  The floorspace of a dwelling shall be measured externally and shall include porches and conservatories, but shall exclude all non-habitable accommodation and detached outbuildings.

3.19  For the purposes of this policy, basements or other fully subterranean structures will not be counted in floorspace calculations (original, existing or proposed), provided where new or extended basements are proposed they do not exceed the footprint of the building. When assessing the creation of a mezzanine, alterations to a roofspace or attached non-habitable accommodation to convert it to habitable accommodation, any internal changes will not be considered to result in a change in floorspace for Green Belt purposes. The exception to this is where the application proposes the relaxation of a planning condition which was imposed to control the conversion to habitable use, or if the non-habitable accommodation has been added since the 31^st December 1968.

3.20  The original building means the building as it existed on 31st December 1968 or whenever it was originally built, whichever is later. This is the base date for when Surrey County Council originally started to apply a percentage guideline to manage development in the Green Belt. Where a building has been extended since this date, this will be taken into account to ensure that extensions are not cumulatively disproportionate.

3.21  Where the size of the original building cannot be established through a site's planning history, or with confidence by a site visit and use of other resources such as historic mapping, the building in its current form will be treated as the original building for the purposes of assessment.

3.22  Domestic garages and other ancillary outbuildings are normally inappropriate in the Green Belt. Where planning permission is required for outbuildings, the Council will have regard to the essential needs of householders for garaging, storage and facilities incidental to the enjoyment of their dwelling. The Council must be satisfied that very special circumstances exist to justify new outbuildings. Any new or enlarged outbuildings must be designed to be clearly subordinate to their host dwelling and not appear intrusive in the landscape.

3.23  There is often pressure to combine the increase in floorspace permitted for extensions and rebuilding at the same time to maximise the increase in floorspace. This approach will not comply with Policy DM14.

3.24  The only circumstances in which a larger building than would normally be acceptable under Policy DM14 may be supported are:

• where permission has been granted for an extension under Policy DM14 but during construction, structural reasons become apparent make it preferable to rebuild the original, rather than extend. The net outcome of such a situation and granting a larger replacement building under Policy DM14 is that it would be identical in built form to the permission for extensions, and the impact on openness of the Green Belt remains the same. In this circumstance, evidence would be required in the form of a structural report, to support rebuild rather than extension,
• where a proposal for a replacement dwelling that may exceed the guideline within Policy DM14 would achieve a smaller and higher quality building than permission previously granted for extensions.

Local Plan Part 1 parent policies	RE2: Green Belt
Monitoring	Indicator: Refusal, and dismissal at appeal, of proposals for inappropriate development in the Green Belt. Target: Avoiding inappropriate development in the Green Belt.