Appeal 3365732

The appeal is allowed, and planning permission is granted for a single storey rear extension and garage conversion at [site address] , [site address] , Walton, Warrington, [postcode] , in accordance with the terms of the application, Ref 2024/01031/FULH, subject to the following conditions:

The development hereby permitted shall begin not later than three years from the date of this decision.

The development hereby permitted shall be carried out in accordance with drawing numbers 1588_03_01 (site plans) and 1588_02_01 (proposed plans); and the [name] dated 10 October 2024, report no. 2056_AMS.01, produced by Lally Tree Management.

The external materials of the extension hereby permitted shall match those used in the existing dwelling, as detailed on the application form.

The submitted plans are not accurate and should not be relied upon for calculating heights and volumes. The elevation plans are partially obscured by images of trees, fail to show the decorative fenestration detail surrounding windows in the older part of the rear elevation, show some first floor windows set within the gables of the roofs, whereas in fact, the top of the windows are below eaves level, and the roofs and gables, including the porch roof, are much higher and steeper than shown. The eaves height of the dwelling is higher above the garage than shown and ornate roof and eaves detailing such as parapets, kneelers and finials are not shown. Only ground floor plans have been provided, and as such, it is not possible to calculate any first floor, roof space or possible basement space. However, the proposals would not alter the majority of the dwelling, the first floor (except a replacement first floor side window), or the roof, and as such, the plans sufficiently demonstrate the siting, scale, layout and appearance of the proposed extension.

The main issues are i) whether the proposal, when taken with previous extensions, would amount to inappropriate development in the Green Belt; and ii) the effect of the development on designated and non-designated heritage assets.

Paragraph 153 of the National Planning Policy Framework (the Framework) makes it clear that inappropriate development is, by definition, harmful to the Green Belt and should not be approved except in very special circumstances. There are exceptions to this general restriction and paragraph 154 states, amongst other things, that the extension or alteration of a building should not be regarded as inappropriate development in the Green Belt provided it does not result in disproportionate additions over and above the size of the original building.

The Framework does not define the term ‘disproportionate additions’ or set out any maximum restrictions or guidance on how this should be assessed. It simply requires consideration of the overall size increase, which can include volume, floorspace, external dimensions and footprint.

Policy GB1 of the Warrington Local Plan 2021/22 – 2038/39 (the local plan) does not specifically refer to extensions to existing buildings in the Green Belt. However, it does require proposals to comply with national planning policy and any relevant Supplementary Planning Documents (SPDs), which are material considerations.

Paragraph 2.4 of the [name] (2021) states that extensions and additions that result in an increase in size of over 33% of the original building (as it existed on 1 July 1948) will be considered disproportionate. It also states that detached outbuildings will be included in calculations. As the SPD is guidance, which is not scrutinised in the same way as development plan policies, the weight I afford to it is reduced, particularly in the absence of any justification for the 33% size increase threshold and the inclusion of outbuildings as extensions.

The host dwelling is a detached house, which is set back from the road within a generous plot. It is apparent from historic ordnance survey maps included within the Heritage Statement submitted with the appeal, that the size, shape and form of the dwelling have altered over time. The planning history of the site also indicates more recent additions, including a two-storey extension and a garage to the side. Whilst the garage is detached from the dwelling, there is a covered passageway between the two buildings.

The parties disagree on the scale and extent of previous extensions, and neither has provided me with clear evidence identifying the extent of the original dwelling. It is also unclear whether the garage or any extensions replaced earlier buildings. Both parties have referred to various floor area and volume calculations, albeit it is unclear how their original and existing volumes have been sourced and calculated. The difference in calculations potentially arises in part from the inclusion of the garage as an extension, or its exclusion as an outbuilding. In light of the discrepancies and lack of supporting evidence, I have afforded the numerical calculations provided by both parties very little weight.

The partial conversion of the garage would not add any volume to the property. The proposed single storey flat roof extension across the rear of the garage and part of the house would not be visible outside of the enclosed and well screened site, due to its position and its limited height and scale. The extension would infill an existing corner of built development and would have a very limited impact on the scale, bulk, massing and built form of the property. Consequently, it would not result in a disproportionate addition to the size of the original dwelling, even when taken with the previous extensions.

I therefore conclude that the proposal would not amount to inappropriate development in the Green Belt and would not conflict with the Framework or Policy GB1 of the local plan. [name] have found that the development is not inappropriate, it should not be regarded as harmful to the openness of the Green Belt and would not conflict with any of the purposes for including land within it.

The site lies within the Walton Village Conservation Area (CA). The Council has submitted a plan outlining part of the CA boundary; however, it is the CA as a whole that forms the heritage asset and against which any effects must be assessed. I have not been provided with a CA appraisal or advised what the Council considers to be its special historic significance. I have had regard to the Conservation Officer comments noted in the Planning Officer’s delegated report, which are somewhat contradictory, stating that there are no heritage issues, raising parking and tree concerns not raised elsewhere, and then concluding there is insufficient information regarding heritage assets, whilst not identifying any harm to these. I have not been provided with the listing details of the adjacent [name] listed [name], nor have I been provided with any local listing or explanation as to why the Council considers the appeal property to be a non-designated heritage asset. Accordingly, my assessment is based primarily upon my own observations and the evidence submitted by the appellants with their application and appeal.

The appeal property is a two-storey mid-19th century dwelling, built in [name] style with later 20th century extensions and garage. It forms part of a group of buildings of similar age and style and makes a positive contribution to the character and appearance of the CA. Its significance is derived from its age and architectural features, together with its group value.

The significance of the CA is derived from the age and architectural quality of the buildings within it, which are situated in spacious plots and tree lined streets, together with its historic interest as a late 19th and early 20th century estate village, developed by the Greenall brewing and landowning family of [name].

[name] is a grade II listed brown brick and stone structure, which carries [address] over the [name]. The road and canal run parallel to the front and rear boundaries of the appeal site, and the bridge is adjacent to the southern point of the site. It was constructed in the mid-18th century, and its significance is derived from its age and its historical and architectural interest. It has not been suggested that the proposal would result in any harm to the heritage significance of the bridge or its setting and I have no reason to reach a different view on this matter given its separation from the proposed extension, which would be located on the northern side of the site.

The existing rear elevation of the property is stepped. The extension would project approximately 4m beyond the existing rear wall of the garage and what appears to be the original rear elevation of the house. It would project approximately 1.8m beyond the rear wall of the existing extension and less than 1m beyond the rear of the inglenook. Although the flat roof extension, large roof lantern and bifold doors would not reflect the architectural style of the original building, the development would be clearly read as a later modern addition and would preserve the original first floor architectural features above it, which are visible from the canal and its towpath. The extension itself would not be visible from outside of the site, which is well screened by the frontage buildings, high gates, fences and mature boundary landscaping.

The side of the extension would run parallel to the side boundary of the property and would require a section of the existing boundary hedge to be pruned back and the removal of two small low quality category C trees, which are not visually prominent outside of the site. These works would not harm the character or appearance of the CA. The extension would be no closer to the boundary than the existing garage and would not appear cramped given the remaining area of garden within the generous plot. As the appeal property is not listed and the partial demolition of a building in a conservation area does not require planning permission, further details relating to the walls of existing buildings to be removed to facilitate the development are not necessary.

I therefore conclude that the proposed extension, due to its modest scale and height and its relationship to existing modern additions to the property, would preserve the significance of the non-designated heritage asset, the setting of the nearby listed bridge and the character and appearance of the CA. Consequently, the proposal would accord with policies DC2, DC6 and ENV8 of the local plan, which collectively seek amongst other things to ensure that new development is of high-quality design and safeguards designated and non-designated heritage assets. In reaching this view I have followed the statutory duties set out in Sections 66(1) and 72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990.

In addition to the standard time limit for commencement, a condition is required to ensure compliance with the approved plans to provide clarity. In the interests of protecting the character and appearance of the area it is also necessary to impose a condition to ensure the external materials of the extension are as detailed on the application form to match the existing dwelling and to ensure compliance with the submitted aboricultural method statement.

The proposal would accord with the development plan, when read as a whole. Material considerations, including the Framework do not indicate that a decision should be taken other than in accordance with the development plan. Having considered all other matters raised, I therefore conclude that the appeal should be allowed.