Part two storey, part single storey rear extension
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Residential Amenity
Extensions
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Inspector’s Reasoning
Appeal Decision
Site visit made on 16 April 2026
by Rachel Hall BSc MSc MRTPI
an Inspector appointed by the Secretary of State
Decision date: 19 May 2026
Appeal: APP/X0415/D/25/3374388
27 Piggotts End, Amersham, Buckinghamshire HP7 0JF
• 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 & Mrs Doyle against the decision of Buckinghamshire Council - East Area
(Chiltern).
• The application reference is PL/25/1692/FA.
• The development proposed is described as ‘part two storey, part single storey rear extension’.
Decision
1. The appeal is allowed and planning permission is granted for part two storey, part
single storey rear extension at 27 Piggotts End, Amersham, Buckinghamshire HP7
0JF in accordance with the terms of the application, Ref PL/25/1692/FA, subject to
the following 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 nos: PE PA 03 Rev A and PE PA 02 Rev C.
3) The external materials of the extension hereby permitted shall match those
used in the existing dwelling.
4) Notwithstanding the provisions of the Town and Country Planning (General
Permitted Development) (England) Order 2015 (or any order revoking and re-
enacting that Order with or without modification), no windows/dormer
windows other than those expressly authorised by this permission shall be
constructed on the flank elevations of the extension hereby permitted.
Preliminary Matter
2. The appeal was accompanied by a Bat Scoping Study (September 2025) (the
scoping study). The Council was given the opportunity to comment on the scoping
study to enable any comments to be taken into account in this appeal. The appeal
is determined having regard to the scoping study and no party is considered to
have been prejudiced in so doing.
Main Issues
3. The main issues are:
• the effect of the proposed development on the living conditions of the
occupants of No 29, with particular regard to light and outlook;
Appeal Decision APP/X0415/D/25/3374388
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• whether the proposal is acceptable with respect to biodiversity, with particular
regard to bats;
• whether the proposal is acceptable with respect to archaeology.
Reasons
Living conditions
4. The proposed rear extension is said to intersect with a 60 degree line taken from
the mid point of the closest rear window of the adjoining property to the south east.
This is understood to relate to No 29 which, although situated to the north east of
the appeal building, is the only adjoining property. The ground floor rear windows
at No 29 enjoy an open aspect. This is particularly evident due to the ground levels
to the rear of No 29 falling steeply away. Consequently, like at the appeal dwelling,
its rear facing ground floor windows have an elevated position relative to land to
the rear. Therefore in the particular circumstances of this case, even if the single
storey proposal would intersect the 60 degree line, it would not result in a harmful
loss of light or outlook experienced from the closest rear facing ground floor
window at No 29. No substantive evidence indicates otherwise.
5. The single storey element of the proposal would be circa 4 metres in height.
However as already noted, the rear gardens at Nos 27 and 29 are much lower
than their ground floor rooms. As a result, when viewed from immediately outside
the back door to No 29, the proposed single storey extension would project only a
relatively short distance above the boundary such that it would not appear
oppressive. From the lower ground level of the rear garden at No 29, the proposed
rear extension would appear more substantial. However, the positioning of a single
storey extension adjacent to the proposed two storey extension would soften the
appearance of the proposal, avoiding a two storey blank elevation adjacent to the
boundary of No 29. Also, the rear building line of the proposal would not extend as
far as that of the rear extension to No 25, resulting in a staggered effect.
Consequently, I find that the proposal would not appear overbearing from the rear
garden of No 29.
6. Therefore, the proposed development would be acceptable with respect to its
effect on the living conditions of the occupants of No 29, with particular regard to
light and outlook. It would thus accord with Policy GC2 of the Chiltern District Local
Plan (consolidated 2011) (Local Plan) which requires that proposals are designed
to ensure sufficient sunlight and daylight reaches adjacent land and buildings. It
would also accord with Policy H14 of the Local Plan, which seeks to ensure
proposals avoid harm to neighbours’ living conditions, through harm to outlook or
loss of light.
Biodiversity
7. The Council considered that insufficient evidence was provided with the planning
application to assess the effect of the proposal on protected species, particularly in
light of the potential for foraging bats in the locality. However, the appeal was
accompanied by a bat scoping study. This assessed the suitability of the building,
both internally and externally, to support roosting bats and nesting birds. The
building was found to be in good condition and to provide negligible suitability for
roosting bats, and no evidence of bird nesting was found. Accordingly, no further
Appeal Decision APP/X0415/D/25/3374388
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survey work was considered necessary. In light of those findings, I see no reason
to conclude otherwise.
8. Therefore, the proposal would comply with saved Policy NC1 of the Local Plan and
Policy CS24 of the Core Strategy for Chiltern District (2011) (Core Strategy).
These generally seek to ensure proposals protect nature conservation interests,
including protected species and biodiversity.
Archaeology
9. The site is said to be in an area of archaeological potential. The Council therefore
considered that the proposal was unacceptable in the absence of a desk-based
assessment and/or field evaluation. However, the appellant submits that the
appeal building could be extended using permitted development rights without the
need for archaeological assessment having been undertaken. In the event of the
appeal being dismissed, I consider there is a real prospect that an alternative
scheme under permitted development rights would be implemented, without the
need for archaeological assessments. Although such an extension may not be as
large as the appeal scheme, it would nonetheless likely involve foundations within
the modest rear garden. Therefore, like the appeal scheme, it would result in
ground disturbance to the rear of the house, even if to a more limited extent than
the appeal scheme. Consequently, the presence of a fallback position is a relevant
consideration here to which I afford moderate weight.
10. Furthermore, I note that the appeal site is in a relatively high density residential
area. Consequently, it appears reasonably likely that the proposed rear extension
would involve land that has already been disturbed to some extent by previous
construction work. Accordingly, in the particular circumstances of this case, I find
that the proposal would be acceptable with respect to archaeology. It would thus
accord with Policies AS1 and AS2 of the Local Plan. These generally seek to
protect archaeological remains.
Conditions
11. In addition to the standard time limit condition, it is necessary for a condition
specifying the approved plans, in the interests of certainty. A condition requiring
the materials match those on the existing building is required in the interests of
ensuring the proposal achieves an acceptable design. Given the location of the
proposed extension adjacent to neighbouring gardens and its elevated position, a
condition restricting permitted development rights such that windows cannot be
inserted on the flank elevations of the proposed development is clearly justified.
This is in order to protect the living conditions of neighbouring occupants with
respect to privacy.
Conclusion
12. For the reasons given, the proposal would accord with the development plan and
therefore the appeal should succeed.
Rachel Hall
INSPECTOR
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