Appeal 6001870

The appeal is dismissed.

I have taken the description of development from the decision notice as the scheme was amended following the submission of the application which reduced the number of units proposed.

Under Article 3(1) and Schedule 2, Part 3, Class MA of the Town and Country Planning (General Permitted Development) (England) Order 2015 as amended (the GPDO), planning permission is granted for development consisting of a change of use of a building and any land within its curtilage from a use falling within Class E (commercial, business and service) of Schedule 2 to the Use Classes Order to a use falling within Class C3 (dwellinghouses) of Schedule 1 to that Order subject to limitations and conditions. This includes flood risk and fire safety.

While not a reason for refusal, in their appeal statement the Council raised concerns over fire safety. The appellant has had opportunity to comment on this and additional comments from the Building Safety Regulator. A revised Flood Risk Assessment report (FRA) C3586-R1-REV-A was submitted at the outset of the appeal along with plans showing the raising of ground floor levels. Therefore, parties would have had chance to comment on them, and no one would be prejudiced by my taking these matters and documents into account in my

Amended plans provided at final comments stage refer to increasing the ground floor levels. Unlike the plans provided at the outset, parties have not had chance to comment on them. Although not altering the number of units, or layout and only relating to internal works, this is a fundamental change relating to the original refusal reason. Therefore, parties, including third parties would be prejudice were these new plans accepted and considered.

The main issues are whether the proposed development would be granted planning permission by Article 3, Schedule 2, Part 3, Class MA of the GPDO with regard to: • flooding risks in relation to the building; and • the fire safety impacts on the intended occupants of the building.

Planning Policy Guidance Flood Risk and [name] (PPG) states that in areas at risk of flooding, developers should undertake a site-specific flood risk assessment to accompany prior approvals such as that subject to this appeal.

The PPG also states it is for the applicant to show that the change of use meets the objectives of the National Planning Policy Framework’s (Framework) policy on flood risk. This includes how the operation of any mitigation measures can be safeguarded and maintained effectively throughout the lifetime of the development. A checklist for site specific flood risk assessments is included in the PPG.

The appeal site is located in flood zone 2 for rivers and residential development is considered ‘more vulnerable’, increasing the vulnerability of the use at the site. Flood zone 2 indicates a medium probability, and an annual probability of between 1 in 100 and 1 in 1000 years.

There would be ground floor residential units. Internal flood levels are said to vary internally for 1 in 100 year plus 70% event but that floor levels would be raised above these. Nonetheless, it has not been shown that the FRA has taken account of ‘Flood risk assessments: climate change allowances’ to ensure that finished floor levels are 1% AEP ([name]) plus climate change allowance.

As such, I cannot be certain that climate change flood heights have been sufficiently assessed. Furthermore, there is no clear evidence of what the levels and impacts would be for greater events such as 1 in 1000-year events. As such, it has not been demonstrated that the ground floor would remain flood free in these events.

Without knowing the extent of flood depths at the site for the worst-case scenarios, I cannot be sure that a condition requiring floor levels to be raised would be appropriate or what other measures would be required. This may have implications for other aspects of the scheme and design.

The FRA states that key routes surrounding the site are at a risk of fluvial and pluvial flooding. Various measures are referred to in the FRA such as flood warnings and those relating to the fabric of the building. However, it also indicates that occupiers would need to seek refuge in the upper floors and remain there. The scheme would still introduce additional residents into a flood zone and rely on them staying in communal areas of the building or within other properties for the duration of the flood event. This is not practical or reasonable and means some residents would not be able to remain in their dwellings until safely evacuated.

The flood risk mitigation measures are also insufficient including in relation to flood warning and evacuation up to and including an extreme event. Again, while some elements could be subject to condition, it would not address the concern over seeking refuge elsewhere in the building. Safe access and egress have not been demonstrated during a flood event.

Consequently, the proposal would lead to unacceptable flooding risks in relation to the building. It would be contrary to the flood risk and management aims of the Framework insofar as they are relevant.

The Council and the Building Safety Regulator have commented on several aspects of the proposed scheme. Nevertheless, while these may require alterations, these matters would also need to be addressed under Building Regulations as separate legislation. If any changes such as external works required a separate or new planning permission or prior approval, then the acceptability of those schemes would be assessed at that point. Similarly, whether the appellant could implement the scheme as proposed would be a matter for them.

As such, from the evidence before me, it has not been shown that the fire safety impacts on the intended occupants of the building would be unacceptable.

I do not have full details of the Runnymede scheme referred to where an evacuation plan was conditioned. From the information provided, that plan related to residents leaving the site before flood waters encroached on the evacuation route, rather than dealing with the scenario of having to remain on site at upper floors. Therefore, it would not be directly comparable to this appeal.

For the reasons given above, I conclude that the appeal should be dismissed.