Construction of first floor side and rear extension, with car port beneath side extension

Appeal Decision Site visit made on 21 July 2025 by C Walker BA (Hons) DipTP MRTPI an Inspector appointed by the Secretary of State Decision date: 06 AUGUST 2025 Appeal Ref: APP/B1930/D/25/3365345 13 Folly Fields, Wheathampstead, Hertfordshire AL4 8HJ • The appeal is made under section 78 of the Town and Country Planning Act 1990 (as amended) against a refusal to grant planning permission. • The appeal is made by Mr Plowright against the decision of St Albans City Council. • The application Ref is 5/24/2162. • The development proposed is construction of first floor side and rear extension, with car port beneath side extension. Decision 1. The appeal is dismissed. Main Issues 2. The main issues are: • whether the development would be inappropriate development in the Green Belt having regard to the National Planning Policy Framework (the Framework) and any relevant development plan policies; • the effect of the development on the openness of the Green Belt; and • whether the harm by reason of inappropriateness, would be clearly outweighed by other considerations, so as to amount to the very special circumstances required to justify the proposal. Reasons Whether inappropriate development 3. The appeal site lies within the Metropolitan Green Belt as defined by Policy 1 of the St Albans District Plan Review (1994) (Plan Review). Policy 13 of the Plan Review sets out that extensions to houses in the Green Belt may be permitted unless the scale or visual impact upon the building originally constructed (or as existing at 1st July 1948, if constructed before that date) would create a building of a significantly larger scale or different character. 4. The more up-to-date Framework sets out at paragraph 154, that development in the Green Belt is inappropriate unless one of several exceptions apply. One of these exceptions include (c) the extension or alteration of a building provided that it does not result in disproportionate additions over and above the size of the original building. Despite the age of the Plan Review policies, their general thrust still broadly aligns with the Framework, and as such I afford them moderate weight insofar as is relevant. Appeal Decision APP/B1930/D/25/3365345 2 5. Disproportionate is not defined by the Framework. However, the Council’s Supplementary Planning Guidance ‘Residential Extensions and Replacement Dwellings in the Green Belt’ 2004 (SPG), gives a number of criteria against which extensions in the Green Belt can be assessed. These include an increase in cubic volume of up to 180m³ or a maximum percentage increase in floor space of 40%, whichever is the greater of the two. These are intended as guidelines and not rigid limits. 6. There is dispute between the parties regarding the extent of the original building. The appellant asserts that the building as it exists today is all original except the modest side porch. This is evidenced by an extract from the 1924 Ordinance Survey Map which shows an L shaped footprint on the plot, which closely matches the dwelling on the ground. Further, I observed on site that the rear projection is finished in the same material as the two-storey element fronting the road, suggesting that it was constructed at the same time. The appellant also points to the slate damp proof course suggestive that it predates 1948. The lack of planning history also supports this stance. Therefore, I am satisfied that the evidence indicates that what is on the ground, minus the side porch, is likely to form the original building. 7. Having found the rear projection to form part of the original building, the original floor space is around 82.9m². The appellant asserts the development would amount to an approximately 32% increase over the original building. However, this does not take account of the ground floor area of the car port as the appellant asserts that it would remain open. Taking the Council’s proposed floor area which does include this space, would bring the percentage increase closer to 58%, beyond the guidance cap set out in the SPG. 8. The Council indicate the volume of the proposed extension would amount to 127.49m³ which the appellant has not disputed in evidence. This is within the SPG guidance range, but this does not have regard to the consideration of its size compared to the original, which is a necessary test in order to comply with the more up-to-date Framework. As such, whilst the guidance in the SPG is useful, its inconsistency with the Framework with regard to the disproportionality test, significantly reduces the weight I attribute it. 9. Volume calculations in terms of the percentage increase of the proposed development are not provided by either party. The open nature of the car port at ground floor level would do very little to diminish the effect of the development on the openness of the Green Belt as the existing detached garage would form the backdrop when viewed from the public realm, thus providing a wall of built form that prevents appreciation of the land beyond. A condition to require the car port to remain open would therefore not negate the harm in this case. Given this finding, I consider that it is reasonable to include the floor space of the car port in the quantitative assessment, as this better reflects the overall effect the development would have on the Green Belt. 10. Consequently, a 58% increase in floor space over the original building would, in my view, amount to a disproportionate addition. Therefore, the proposal would be inappropriate development in the Green Belt. This brings the scheme into conflict with the Framework, which requires me to place substantial weight to any harm to the Green Belt. As the proposal would be of a significantly larger scale to the original building, it also conflicts with Policies 1 and 13 of the Plan Review. Appeal Decision APP/B1930/D/25/3365345 3 Openness 11. Introducing a first-floor side extension, albeit set back from the roadside, would considerably increase the scale and massing of the original building, which by its very nature would erode the openness of the Green Belt, reducing the gap between buildings and the glimpses of the open land at its rear. The extension would have a permanent spatial and visual presence from the public realm. As such it would undermine a fundamental aim of the Green Belt which is to keep land permanently open, as set out in paragraph 142 of the Framework. Other considerations 12. The appellant asserts that the first-floor extension would facilitate a modern standard of living. However, my attention has not been drawn to any specific deficiencies of the existing living environment. It is not unusual for a dwelling of this age and form to lack an upstairs bathroom. I afford this limited weight. 13. A betterment in respect of off-street parking is advanced, through the removal of the side porch, which would allow for one additional vehicle to pull in off the road. Noting the narrow nature of the road network around Folly Fields and that many dwellings appear to lack off-street parking facilities, this would be a benefit weighing in favour of the scheme. However, I have little evidence to show how this would amount to the very special circumstances required to justify the proposal. Conclusion 14. I have found that the scheme constitutes inappropriate development, and that the openness of the Green Belt would be compromised by the development. The Framework requires that substantial weight should be given to any harm to the Green Belt. This weighs heavily against the scheme. 15. Paragraph 153 of the Framework is clear that inappropriate development is, by definition, harmful to the Green Belt and should not be approved except in very special circumstances (VCS). VSC will not exist unless the potential harm to the Green Belt by reason of inappropriateness, and any other harm resulting from the proposal, is clearly outweighed by other considerations. 16. I have given limited weight to the other considerations in favour of the development. I am not satisfied that the harm to the Green Belt would be clearly outweighed by the other considerations. Consequently, the VSC circumstances to justify the scheme do not therefore exist. 17. For the reasons set out above, the proposal conflicts with the development plan and there are no material considerations, including the Framework, that would outweigh the conflict. I therefore dismiss the appeal. C Walker INSPECTOR