Two-storey rear extension, side dormer window, alterations to retaining wall

Appeal Decision Site visit made on 8 July 2025 by A Price BSc MA MRTPI an Inspector appointed by the Secretary of State Decision date: 30 July 2025 Appeal Ref: APP/B1930/D/24/3355310 Astridge Farm, Gustard Wood, Wheathampstead, Hertfordshire AL4 8LA • 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 Bernard Palmer against the decision of St Albans City & District Council. • The application Ref is 5/23/2123. • The development proposed is two-storey rear extension, side dormer window, alterations to retaining wall. Decision 1. The appeal is allowed and planning permission is granted for two-storey rear extension, side dormer window, alterations to retaining wall at Astridge Farm, Gustard Wood, Wheathampstead, Hertfordshire AL4 8LA in accordance with the terms of the application Ref 5/23/2123 subject to the conditions in the attached schedule. Preliminary Matters 2. The appeal property is a Grade II listed building and the proposal is the subject of a separate listed building consent. This is dealt with in further detail below. Main Issues 3. The main issues are: • whether the proposed 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; • if the proposed development is inappropriate, the effect of the proposal on the openness of the Green Belt; and • if the development is inappropriate, whether the harm by reason of inappropriateness, and any other harm, would be clearly outweighed by other considerations so as to amount to the very special circumstances required to justify the proposed development. Reasons Whether inappropriate development in the Green Belt 4. The appeal site is located within the Green Belt. National Green Belt policy in the Framework sets out that inappropriate development is, by definition, harmful to the Green Belt and should not be approved ‘except in very special circumstances.’ Appeal Decision APP/B1930/D/24/3355310 2 There are, however, certain exceptions. One of those, at paragraph 154, is 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’. Policies 1 and 13 of the St Albans District Local Plan Review 2004 (LP) broadly conform to the general thrust of national Green Belt policy in respect of extensions. The Residential Extensions and Replacement Dwellings in the Green Belt Supplementary Planning Guidance (the SPG) gives more detailed guidance. It sets out that increases in cubic content limited to 90-180sqm or an increase in floorspace of 20-40% may be acceptable subject to performance against other criteria. 5. The definition of original building in the Framework is set out as ‘a building as it existed on 1 July 1948 or, if constructed after 1 July 1948, as it was built originally.’ The SPG, at 7.1 (ii) sets out that existing garages and outbuildings can be included as part of the original floorspace if they were built at the same time (or existed on 1 July 1948) and are integral to the original dwelling. There was doubt under the previous appeal1 as to whether the existing outbuildings could reasonably be considered to form part of the original floorspace. The appeal effectively fell on this point. 6. However, further information has been provided in support of the current appeal scheme, including a breakdown of the floorspace for each historic outbuilding and its use. This includes the main farmhouse and nearby outbuildings of two barns, stable block, ancillary building and Willow Cottage. In total, the cumulative floorspace of these buildings is claimed to measure approximately 588sqm. 7. Based on the evidence before me and my observations on site, I have no reason to doubt these figures or the age of the buildings (pre-1948). Based on the layout of the complex of buildings, their direct physical and visual relationship with the farmhouse and their existing ancillary uses (storage, games room and guest accommodation), I am satisfied that they currently form outbuildings which are integral to the main house, and which could reasonably be included as original floorspace. In particular, there is no substantive evidence before me to demonstrate that Willow Cottage is used as a separate dwelling. This is set within the main farmyard and is accessed via the same private drive and gateway as the farmhouse and wider complex. There are no other indicators which would lead me to conclude that this, or any other outbuildings, are used by anyone other than those connected with the main dwelling. 8. Therefore, while the extent of accommodation across the site is generous, I accept the appellant’s figures which conclude that there would be an approximately 47% increase in floorspace when taking into account original floorspace and previous and proposed extensions. I am aware that this figure exceeds the guidance set out within the SPG. However, this would be only marginally over those figures and given that this is guidance (clearly stated as such within the SPG), I am of the view that the proposed scheme could, in this instance, be described as a proportionate addition to the original building. 9. The Council argues that no details of the existing pool house have been provided. I acknowledge this and have considered whether it should be included within figures for previous extensions, having been built later than 1948. However, I note 1 APP/B1930/W/20/3256314 Appeal Decision APP/B1930/D/24/3355310 3 that the guidance at Table 3 of the SPG specifies that garages and outbuildings within 5m of the original dwelling will be classed as an extension. As the distance between the main dwelling and the pool house exceeds that distance, I do not consider that the pool house could reasonably be considered a previous extension for the purpose of these Green Belt calculations. Its existence has, therefore, not changed my conclusion on this main issue. 10. The proposed extension would result in the loss of a mature cherry tree at the site. However, the reason for refusal does not specifically refer to the effect on character or appearance or trees. Moreover, the previous inspector acknowledged the loss of this tree, noting the retention of the site’s extensive trees and planting overall. I concur with this, and it has not lead me to an alternative position. 11. Overall, I conclude that the development is not inappropriate development in the Green Belt. The proposed development would therefore accord with paragraph 154 of the Framework and the relevant provisions of LP Policies 1 and 13 and the SPG which, in summary, seek to protect the Green Belt from inappropriate development. Other Matters 12. The development relates to a Grade II listed building, Astridge Farmhouse. Mindful of the statutory duty set out in sections 16(2) and 66(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990, I have had special regard to the desirability of preserving the building or its setting or any features of special architectural or historic interest which it possesses. Given the location, design and extent of the development, I consider that it would preserve the special interest and significance of the listed building. I note the Council had no concerns in this regard either and that a separate listed building consent has been obtained. Conditions 13. The Council has suggested a set of conditions in the event that the appeal is allowed. In imposing conditions, I have had regard to the tests within the Framework and the Planning Practice Guidance, and have accordingly amended the wording of certain conditions proposed by the Council without altering their aim. 14. In addition to the standard time limit condition, I have imposed a condition requiring compliance with the relevant plans. This is imposed in the interests of certainty. I have imposed a condition requiring detail and samples of the proposed external materials. This is necessary in the interests of certainty and character and appearance. This is pre-commencement for certainty and to ensure that materials are properly designed in prior to the commencement of development. Conclusion 15. For the above reasons, having had regard to all matters raised, I conclude that the development accords with the development plan as a whole and therefore the appeal should be allowed. A Price INSPECTOR Appeal Decision APP/B1930/D/24/3355310 4 SCHEDULE OF CONDITIONS 1) The development hereby permitted shall begin not later than three years from the date of this decision. 2) The development hereby permitted shall be carried out in accordance with drawing numbers: NA-23039-PL-100 (site location and block plan); NA- 23039-PL-200 (existing and proposed plans); NA-23039-PL-300 (existing and proposed elevations and site photos). 3) No development shall take place until details and samples of the materials to be used in the construction of the external surfaces of the development hereby permitted have been submitted to and approved in writing by the Local Planning Authority. The details shall include roof materials, rainwater goods and mortar type. The development shall be carried out in accordance with the approved details.