3 APPLYING THE ORDER
3.1 Article 3 of the 1992 Order grants planning permission for the classes of development set out in Schedule 1, subject to the limitations and conditions listed below each class. There are also a number of standard conditions that will apply to all classes. The proposed Order amends Schedule 1 in so far as it relates to householder permitted development. The new classes are as follows:
Class 1 - Any enlargement of a dwellinghouse by way of a single storey ground floor extension, including any alteration to the roof required for the purpose of the enlargement.
3.2 Single storey ground floor extensions are the most common form of householder development. The following is a brief commentary for each of the 5 limitations applying to this class of development. Where a limitation is similar to the 1992 Order or has been discussed in previous sections this is noted.
(a) any part of the development would be in front of the principal elevation or side elevation where that elevation fronts a road;
3.3 This limitation has been discussed above in paragraphs 2.2 - 2.11.
(b) any part of the development would be within 1 metre of the boundary of the curtilage of the dwellinghouse and it would extend beyond the line of that part of the rear elevation nearest that boundary by more than-
(i) 4 metres in the case of a detached dwellinghouse, or
(ii) 3 metres in any other case;
3.4 This limitation only applies if any part of the extension is within 1 metre of the boundary of the curtilage. If that is the case, an extension can only project from the line of the rear elevation nearest to the boundary by 4 metres if a detached house or 3 metres in any other case. This is shown in illustration in Figure 8 below. There will be circumstances where an extension does not project from a rear wall, e.g. a side extension, in which case the limitation is complied with.
Figure 8: If any part of the proposed extension falls within the shaded area, then the extension can project up to 4m, for detached dwellinghouses and 3m for any other case. If the development is wholly outside of the 1 metre boundary the size of the extension is controlled by section (d) below.
(c) the height of the development would exceed-
(i) 4 metres in the case of a dual pitched roof; or
(ii) 3 metres in any other case;
3.5 Restricts the height of the extension and uses the same thresholds as the 1992 Order. The phrase dual pitched roof is used so as to exclude mono pitched roofs from the 4 metre threshold. For the purposes of measuring the height of a building, householder development classes measure heights from the lowest part of the ground level adjacent to the building.
(d) the developed area of each of the front and rear curtilages of the dwellinghouse would be larger than the undeveloped area of each curtilage.
3.6 This limitation has been discussed above in paragraphs 2.12 - 2.15.
(e) it would be within a conservation area or within the curtilage of a listed building and the footprint of the resulting building would exceed that of the original dwellinghouse by 16 square metres or more.
3.7 Within a conservation area or within the curtilage of a listed building the size of the extension is limited to 16 square metres. This is the same size as used in the 1992 Order and is a one off threshold, and therefore any previous extensions count against that limit.
Class 2 - Any enlargement of a dwellinghouse, other than a single storey ground floor extension, including any alteration to the roof required for the purpose of the enlargement
3.8 This Class is for any other enlargement that is not a single storey extension. Most typically, this would be either a 1_ storey extension or a 2 storey extension. Sub-paragraph 2(a) provides that no part of the extension can be within 10 metres of the boundary of the curtilage.
3.9 Curtilage has been discussed in paragraphs 2.12 - 2.15 above. A 1_ storey or 2 storey extension runs the most risks in terms of overshadowing, physical impact and overlooking. It was considered that a distance of 10 metres would be the minimum distance sufficient to be sure that such impacts would be acceptable. It is recognised that the majority of houses would be unable to meet this criteria and therefore, as now, most 1_ or 2 storey extensions will require planning permission.
3.10 Sub-paragraph (2)(b) limits the height of the extension so that it cannot exceed the height of the roof; normally this would be the ridge of the roof. Sub-paragraph 2(c) means that planning permission is required if the house is in a conservation area.
3.11 Sub-paragraph (2)(d) is necessary to make sure proposals that enlarge the house by way of a roof alteration (unless the roof alteration is part of the extension) are considered under Class 4.
Class 3 - Any improvement or other alteration to the external appearance of a dwellinghouse that is not an enlargement
3.12 The definition of enlargement is key to understanding how Class 3 relates to extensions in Class 1 and Class 2. Enlargement is defined as any development that increases the internal volume of the original dwellinghouse and includes a canopy or roof, with or without walls, which is attached to the dwellinghouse (including a car port) but does not include a balcony. Class 3 developments would include replacement windows and doors, satellite dish, cladding, painting, new flue etc.
3.13 Sub-paragraph (2)(a) limits the protrusion to 1 metre from the wall. Having isolated all other alterations and improvements (apart from extensions), the Order allows any such changes as permitted development. This can best be visualised as allowing a 1 metre bubble surrounding the walls and roof of a house, within which a householder will not require planning permission. Sub-paragraph 2(b) prevents balconies (which are not included in the definition of enlargement) in order to prevent overlooking and loss of privacy.
3.14 Sub-paragraph (2)(c) means that Class 3 does not apply within a conservation area or to development within the curtilage of a listed building. As discussed in paragraph 2.18 this is an increase in restrictions compared to the current 1992 Order.
3.15 Sub-paragraph (2)(d) means that installation of flues for biomass heating systems or part of heat and power system fuelled by biomass sources within Air Quality Management Areas will require planning permission.
3.16 Sub-paragraph (2)(e) is necessary to ensure any alteration to the roof is considered under Class 5.
Class 4 - Any enlargement of a dwellinghouse by way of an addition or alteration to its roof
3.17 This Class typically relates to a dormer extension to a roof. The 1992 Order limits all but the smallest of changes to a roof. This is considered unduly restrictive.
3.18 It is accepted that a badly designed dormer can detrimentally affect the visual appearance of a dwellinghouse. The larger the dormer, the more challenging it is to produce a good design. Also, a dormer may result in it being possible to see into neighbouring garden areas. However, a degree of mutual overlooking is commonplace in residential areas and it should not be the purpose of the planning system to protect perceived individual property rights. Therefore, Class 4 allows side and rear facing dormers, subject to size limitations. This is considered to strike the best balance between providing a reasonable relaxation of controls, whilst at the same time placing a limit on the size of a dormer, controlling where most likely to be in the public view and maintaining the restrictions for conservation areas and listed buildings.
3.19 For the above reasons sub-paragraph 2(a) controls a roof enlargement if it is on a roof plane fronting a road. This would typically be the front, but could be a side or rear facing roof plane if a road, bounding the curtilage, happened to be on the side or rear.
3.20 Sub-paragraphs 2(b) and (c) limit the scale of any dormer. For it to be permitted development, it must not exceed half the width of the roof plane (the width of the roof plane is measured from the eaves line) or be within 0.3 metres of the edge of the roof plane. For example, the ridge of the roof or the edge of a hipped roof.
Class 5 - Any improvement or other alteration to the external appearance of the roof of a dwellinghouse that is not an enlargement
3.21 As with Class 3, the definition of enlargement is key to understanding the relationship between Class 4 and Class 5. Class 5 is intended to cover such alterations as a satellite dish, solar panel, new flue, new roofing materials etc. It adopts the same 1 metre "bubble" concept as previously discussed in part 2 and Class 3 above. The limitations are also the same as Class 3.
Class 6 - The provision within the curtilage of a dwellinghouse of any building required for a purpose incidental to the enjoyment of a dwellinghouse or the maintenance or improvement of such a building
3.22 Class 6 is intended to relate to buildings that were previously considered under Class 3 of the 1992 Order. Sub-paragraph (2)(a) ensures the building cannot be used as a separate dwelling.
3.23 Sub-paragraph (2)(b) uses the principal elevation concept to isolate the rear garden. The principal elevation concept has been discussed in Part 2 and in relation to Class 1 above. How the principal elevation is identified is also explained in more detail in Annex C.
3.24 Sub-paragraph (2)(c) limits the height of the building and is the same used in the existing 1992 Order and Class 1 above.
3.25 Sub-paragraph (2)(d) adds an additional height limitation of 2.5 metres for any building within 1 metre of the boundary of the curtilage. Sub-paragraph 2(e) relates to the site coverage criteria that has been discussed in Part 2 and Class 1 above. More explanation as to how this is applied is also provided in Annex C.
3.26 Sub-paragraph (2)(f) limits the footprint to 4 square metres for any building in a conservation area or curtilage of a listed building. This is a similar limitation that in the 1992 Order.
Class 6A - The carrying out of any building, engineering, installation or other operation (other than a Class 6 development) within the curtilage of a dwellinghouse, required for a purpose incidental to the enjoyment of that dwellinghouse
3.27 Class 6A relates to all other forms of development other than a building. Building operation is included in the description of Class 6A, as in terms of the definition of development a building operation would include a wider range of development than just the provision of an actual building. It is intended to apply to garden works, some micro-generation equipment, e.g. solar panels, tennis courts, flag poles and oil tanks etc.
3.28 Sub-paragraph (2)(a) is intended to isolate the rear garden and has been discussed previously in Class 1 and Class 6. Sub-paragraph (2)(b) limits the height of any such structure to 3 metres, which is consistent with the heights used in Class 1 and Class 6.
3.29 Sub-paragraph (2)(c) relates to the site coverage criteria that has also been used for Class 1 and Class 6 and has been discussed above.
3.30 Sub-paragraph (2)(d) would restrict Class 6A developments in a conservation area or the curtilage of a listed building. The effect of sub-paragraphs (2)(e) to (h) is that the provision of a hard surface, decking, fences and the creation of a new access are not covered by Class 6A but by Classes elsewhere in the Order.
Class 6B - The provision within the curtilage of a dwellinghouse of a hard surface for any purpose incidental to the enjoyment of the dwellinghouse or the replacement in whole or in part of such a surface
3.31 Class 6B is similar to Class 4 of the 1992 Order. However, there are two important distinctions; it now covers whole or partial replacement of hard surfaces and is subject to a condition requiring porous materials to be used or that provision is made for surface water run off to be directed to a porous area on site.
3.32 This proposed change is similar to the provisions in the 2008 English Order. Its introduction follows a review of extreme flooding events and concerns expressed by regulatory authorities and water companies that the cumulative impact of small increases in hard surfacing is leading to increased run off into road drains that ultimately flow into watercourses or sewage treatment works. The intention of the condition is to encourage householders to adopt the principles of source control.
3.33 The Scottish Government accepts that it will be difficult for planning authorities to detect whether this condition has been complied with. However, this measure will not be applied in isolation. In addition to this planning rule change, the Scottish Government will be working to introduce a range of measures including, public and industry education, awareness and training, home insurance questions and publication of technical standards.
3.34 Sub-paragraph (3) means that planning permission is needed for hard surfaces in conservation areas and in the curtilage of listed buildings, as is the ,case with the existing Class 4.
Class 6C - The erection, construction, maintenance, improvement or alteration of any deck or other raised platform within the curtilage of a dwellinghouse for any purpose incidental to the enjoyment of the dwellinghouse
3.35 The Government is introducing a new Class for decking because there are no obvious Classes for considering decking in the,1992 Order and planning authorities adopt different interpretations.
3.36 Sub-paragraph (2)(a) is intended to isolate the rear garden. The application of the principal elevation has been discussed in part 2 and previous Classes. More detail on how it is applied is explained in Annex C.
3.37 Sub-paragraph (2)(b) limits the height of the platform of the decking to 0.5 metres. This is the same height as used in the 2008 English Order. Sub-paragraph 2(c) limits the total height, for example if screens are attached, to 3 metres to be consistent with Classes 1, 6 and 6A.
3.38 Sub-paragraph (2)(d) limits the area of decking in conservation areas and within the curtilage of listed buildings to 4 square metres. This reflects the same limitation used in Class 6 and that used in the 1992 Order. Outwith conservation areas it was not considered necessary to have a site coverage limitation as the main adverse impact from decking only occurs if it is raised unduly relative to surrounding land. The height controls are therefore considered to be adequate.
Class 6CA - The erection or construction of any porch outside any external door of a dwellinghouse
3.39 This is a new Class. Sub-paragraph 2(d) does not allow porches to be permitted development within conservation areas.
Class 6CB - The erection, construction, maintenance, improvement or alteration of any gate, fence, wall or other means of enclosure any part of which would be within or would bound the curtilage of a dwellinghouse
3.40 This Class is similar to Class 7 of the 1992 Order except that the principal elevation concept is used to isolate the rear, instead of distance from a road.
Class 6CC - Any improvement or other alteration to the external appearance of a building containing one or more flats
3.41 This is a new Class and extends the principles established in Class 3 and 5 for houses to flats. Sub-paragraph 2(b) would allow the replacement of a window or door frame but not the enlargement of an existing opening. Sub-paragraph 2(c) means that installation of flues for biomass heating systems or part of heat and power system fuelled by biomass sources within Air Quality Management Areas will require planning permission. Sub-paragraph 2(d) means this Class would not apply in conservation areas.