92 Turkey Street EN1 4PT
The Brief
RIDA Reports Ltd was appointed to undertake a detailed flood risk assessment for a proposed residential development at 92 Turkey Street, Enfield (EN1 4PT).
The project involves the change of use of the existing C3 dwelling house into a C4 House in Multiple Occupation (HMO). The proposed works also include a single-storey rear extension, a rear dormer involving a roof extension, front rooflights, and associated amenity, cycle, and refuse storage spaces within the current garden area.
Why the Client Chose RIDA
Converting a residential dwelling into a larger HMO and extending its footprint requires robust planning support, particularly when the site is situated in a high-risk flood area.
The client required a specialist consultancy capable of delivering a detailed flood risk assessment that strictly adhered to the National Planning Policy Framework (NPPF) and the London Borough of Enfield’s 2021 Strategic Flood Risk Assessment (SFRA).
RIDA was selected for its proven expertise in navigating site-specific flood constraints and delivering the technical evidence necessary to seamlessly support residential change-of-use planning applications.
The Challenge
The primary constraint for the proposed development was its location within River Flood Zone 3, which indicates a high probability of fluvial flooding. While the current garden area is classified as ‘Water compatible’, the conversion into an HMO and the addition of a rear extension introduced a ‘More vulnerable’ development classification.
The core challenge was to demonstrate that this increased vulnerability could be safely managed over the building’s design life without placing future occupants at risk or exacerbating flood conditions for neighbouring properties.
The RIDA Difference
RIDA conducted a detailed flood risk assessment, evaluating the site against the latest Environment Agency data and local Enfield SFRA mapping.
To address the high fluvial flood risk associated with Flood Zone 3, the team formulated a site-specific flood risk management strategy.
This approach focused on detailing appropriate mitigation measures tailored to the new ground-floor rear extension and the overall HMO conversion, ensuring that the new habitable spaces and storage areas would be adequately resilient to potential river flooding without disrupting existing flood flow pathways.
The Outcome
The detailed assessment successfully demonstrated that the proposed HMO conversion and rear extension could be safely accommodated on the site.
By outlining policy-compliant mitigation measures to manage the fluvial risks of Flood Zone 3, RIDA ensured the development would remain safe throughout its design life and would not increase flood risk elsewhere. The comprehensive report provided the robust technical justification required to fully support the client’s planning application to the local authority.