Replacement of a previously existing outbuilding

Appeal Decision Site visit made on 3 September 2026 by John Felgate BA (Hons) MA MRTPI an Inspector appointed by the Secretary of State Decision date: 9th September 2026 Appeal Ref: 6010292 Rose Cottage, Kentish Lane, Hatfield, Hertfordshire AL9 6JP • 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 Mrs Sally Fitzgerald against the decision of Welwyn Hatfield District Council. • The application reference number is 6/2025/2623/HOUSE. • The development proposed is the replacement of a previously existing outbuilding. Decision 1. The appeal is dismissed. Preliminary matters 2. The application seeks retrospective planning permission for works that have been started. At the time of my visit, the parts that had been completed comprised the steel frame of the walls and roof, the plinth walls in brick and blockwork, and the concrete floor slab. 3. The appellant states that she was unaware of the need for planning permission, because the new building was intended as a replacement for an earlier one on the same site. I see no reason to doubt this explanation. 4. On 17 August 2026 a revised National Planning Policy Framework (the NPPF) was published. The appellant and the Council were invited to comment on the relevance of the new policies to this appeal, and I have taken account of their responses. Main issues 5. The main issues in the appeal seem to me as follows: ▪ whether the proposal would comply with the relevant policies relating to development in the green belt; ▪ the effects on the character and appearance of the area; ▪ and the effects on living conditions at the adjoining property, Cherry Tree Cottage. Reasons for decision Green belt policy 6. The Local Plan for the area is the Welwyn Hatfield Borough Local Plan (the LP), adopted in October 2023. In that plan, Policy SADM 34 states that development proposals in the green belt are to be treated in accordance with relevant national Appeal Decision 6010292 2 policy, and that replacement buildings will permitted where the new building is not materially larger than the one it replaces, and is for the same use. 7. The national policy to which the above LP policy refers is now the revised NPPF. In that document, Policy GB6 states that ‘inappropriate’ development in green belts is to be regarded as harmful by definition, and should not be approved except in very special circumstances. In this context, all development is to be treated as inappropriate unless it falls into one of the categories in NPPF Policy GB7. 8. One of these exceptions, under Policy GB7’s section (b), is where the development is the replacement of an existing building. However, as in LP Policy SADM 34, this exception is only available where the new building is not materially larger than the one that is to be replaced. And in addition, the NPPF policy also requires that the existing building should be lawful in planning terms, and be of permanent and substantial construction. 9. In the present case, the former building that stood on the site until recently was evidently a single-storey timber shed, which stood in the garden of Rose Cottage, and is said to have housed various kinds of vehicles and aircraft, for hobby purposes. That building was about 12m long by just over 6m wide. The new building which is now under construction would have an almost identical footprint. 10. However, the previous building evidently had a gambrel-style roof, with a low eaves line at a height of around 2m, and its main ridge at about 4.6m. Whereas, in the partially-completed replacement building, the eaves are at 4.6m and the ridge at 5.8m. In addition, the roof has been turned through 90 degrees, so that the gables are on the building’s long sides, rather than its ends. These changes in the shape and orientation of the roof add significantly to the new building’s overall height and volume. The replacement building would therefore be materially larger than the original. 11. In addition, the appellant’s photographs show the former building to have been constructed primarily of what appears to have been timber boarding and plywood panels, mounted on a lightweight frame, with no internal linings or finishes, and with its windows formed out of transparent plastic sheeting. These are materials that would not normally be described as either permanent or substantial. The building is said to have been erected in 1995, but has now been demolished, after no more than about 30 years. The appellant’s photographs show that, prior to this, the building had already fallen into some disrepair, and the accompanying statement confirms that by then it was no longer watertight. All the evidence therefore points to the fact that the original building was not of permanent or substantial construction, but was in fact essentially always a short-life structure which, by the time it was taken down, had already outlived its useful life. 12. Consequently, on both of these grounds, relating to size and permanence, the appeal proposal falls outside the terms of the exception that NPPF Policy GB7(b) provides for replacement buildings. 13. As residential garden land outside any built-up area, the appeal site could potentially be considered as previously developed land (PDL). But the exception for development on PDL, at Policy GB7 section (e), is limited to cases where the scheme does not cause substantial harm to the green belt’s openness. In the present appeal, it is clear in my view that the increase in built volume would result in a considerable loss of openness, in both visual and spatial terms. It follows, to Appeal Decision 6010292 3 my mind, that the resultant harm to the green belt would be substantial. The exception under Policy GB7(e) is therefore not applicable in this case. 14. I also acknowledge that, in some circumstances, a detached outbuilding may also potentially benefit from the exception for extensions and alterations. However, that provision is dependent on the development not resulting in disproportionate cumulative additions over and above the size of the original dwelling. In this case, taking account of the various other extensions and outbuildings already in existence at the property, that threshold appears to have been already passed. 15. In the light of all the above therefore, I find that the proposed scheme falls outside the terms of any of the allowable exceptions to green belt policy, within NPPF Policy GB7. I also find that the development would result in substantial harm to the green belt’s openness. It follows that the proposal would constitute inappropriate development in terms of NPPF Policy GB6, and this in turn means that it would conflict with LP Policy SADM 34. The harm to the green belt, by reason of inappropriateness, and due to the loss of openness, carries substantial weight in the overall planning balance. Effects on the area’s character and appearance 16. The lane which runs alongside the appeal site and Cherry Tree Cottage provides access to those properties and to two farmsteads, and then continues as a public bridleway, joining the Hertfordshire Way walking route at the village of Newgate Street. The appeal building stands about 10m or so from the lane, and I saw on my visit that, even in summer conditions, it is clearly visible through the frontage trees. In winter views, its visibility would be likely to be increased. 17. In its present, partly completed state, the building frame appears as a large and prominent structure, with its height and mass clearly dwarfing the existing one- and-a half storey garage/annex nearby. When completed, with the addition of the proposed cladding panels to the walls and roof, the building would take on a more solid form, and this would be particularly noticeable in the case of the long, gabled, side elevation, facing towards the lane. As a result, the new building would become still more visually dominant. 18. Whilst the general style and materials might bear some resemblance to an agricultural building, they would not be sympathetic to their immediate residential surroundings. In particular, the transverse ridge, running across the building’s width rather than its length, would be contrary to the more conventional building forms seen nearby, so as to appear visually jarring in this location. 19. I note the suggestion that additional planting could be carried out to reduce the new building’s visibility. But given the proximity of the building’ to the boundary, and to the existing trees, it is not clear whether sufficient space is available, or whether any such new planting would have any reasonable prospect of survival. In any event, new tree planting would take several years to have any significant screening effect. 20. Overall therefore, it seems to me that the proposed development would result in an unattractive and unpleasing building, out of scale with its neighbours, and at odds with their architectural style. As such the scheme would cause harm to the area’s character and appearance, contrary to LP Policy SP9, which requires a high quality of design and respect for the site’s local context. Appeal Decision 6010292 4 Effects on the adjoining property 21. The new building stands close to the boundary with Cherry Tree Cottage. However, the majority of the boundary is adequately screened with trees and bushes. The building would be visible from the upper floor windows of the dwelling itself, but only at a distance of nearly 30m. At that distance, the development would have no significant impact on outlook, and would not appear overbearing. there would therefore be no material impact on living conditions, and no conflict in this regard with LP Policy SADM 11. Other matters 22. I note the appellant’s willingness to make modifications to the scheme if necessary, and to accept conditions to that effect. But there is no evidence of any such modifications or conditions that would overcome the planning objections identified above, in terms of green belt policy or character and appearance. Planning balance and conclusion 23. For the reasons set out above, I have found that the completion of the proposed building would amount to inappropriate development in terms of green belt policy, and would also cause additional harm to the green belt due to the resulting loss of openness. In these respects the proposal would conflict with LP Policy SADM 34. Harm would also be caused to the area’s character and appearance, because of the poor quality of the design, contrary to Policy SADM 11. The scheme would therefore be contrary to the statutory development plan. 24. The development would, in part, replace a previous building, which had evidently reached the point where its removal was a benefit to the area. But that building no longer exists, and cannot now be re-erected. The benefit gained from its removal is therefore not dependent on the appeal proposal. And in any event, due to the excessive size and poor design of the replacement building, the development now proposed would not represent an improvement over the original. Given that the works already carried out must have involved a substantial cost, it is presumed that the completion of the scheme would help to meet some kind of need of the appellant’s own. But in the absence of any information regarding the nature of that need, this carries little weight. No other potential benefits or special circumstances have been identified. 25. NPPF Policy GB6 makes clear that the ‘very special circumstances’ that are necessary to justify development in green belts will not exist unless the harm is clearly outweighed by other considerations. In this case, on the evidence available to me, there appear to be no such other considerations of any significant weight. It follows that the harm to the green belt is not outweighed. 26. I have considered all the other matters raised, but none changes the above conclusion. The appeal is therefore dismissed. J Felgate INSPECTOR