Flood Risk Assessments for House Extensions
Extending in Flood Zone 2 or 3? A planning-ready FRA for single-storey, two-storey, side and rear extensions — proportionate, affordable and written to pass first time. From £295.
FRAs for House Extensions
If your home sits in Flood Zone 2 or 3, even a modest extension usually needs a Flood Risk Assessment to validate the planning application. The good news is that a householder extension is a proportionate case — the FRA can be concise and affordable while still satisfying the LPA and Environment Agency standing advice.
We set out the site's flood risk, show the extension is safe and doesn't increase risk elsewhere, and recommend proportionate flood-resilient measures and finished floor levels where needed. Most extension FRAs are delivered within 3–5 working days from £295.
What's included
- EA flood zone & sources review
- Extension-specific risk assessment
- Flood-resilient design measures
- Finished floor level advice
- Safe access & escape (if relevant)
- Surface water / drainage note
- EA standing advice compliance
- Planning-ready FRA report
When your extension needs an FRA
Location and size determine whether an FRA is required with your householder application.
Flood Zone 2 or 3
If your property is in Flood Zone 2 or 3 on the EA Flood Map for Planning, an extension almost always needs an FRA to be validated.
Surface water flood risk
Even in Flood Zone 1, a history of surface water flooding or a nearby watercourse can prompt the LPA to request a flood risk assessment.
Basements & habitable space
Extensions creating bedrooms or basements are more vulnerable and need clear evidence of safe floor levels and resilience.
LPA has requested one
If your planning officer or a validation checklist has asked for an FRA, we'll turn a proportionate report around quickly.
Frequently Asked Questions
Related services: Home Flood Risk Assessment • When Do I Need an FRA? • FRA for a House Extension?
Trusted by Developers, Architects & Planning Consultants
★★★★★ 5.0 from 6 Google reviews
“Antony was great to work with when we needed a Flood Risk Assessment and Emergency Flood Plan. As an architect I would definitely use FRE Consultants again… his report went a good way in helping us get planning permission on a tricky site. Highly recommended.”
“Antony carried out my Flood Risk Assessment and has done a great job. My architect commented that the report was professionally drafted and very easy to follow. I highly recommend Antony's services.”
“Antony carried out a SuDS report for one of our projects and provided an excellent service throughout — quick to respond, clear communication, and a thorough, detailed report within the agreed timescale. We will certainly be using his services on all future projects!”
“Extremely helpful, prompt and friendly service carrying out a Flood Risk Assessment for a home project that required planning permission in a flood risk area… the price was reasonable and given up-front, and the final report was highly professional and exactly as required.”
“I had an extension completed on my house and needed a Flood Risk Assessment for planning. The service received was great and at a competitive cost. We were granted planning after first submission.”
“Nice and quick service. Recommend A++”
Extending in a flood zone?
Send us your address and plans for a fixed-fee extension FRA quote within 24 hours.
Get a Free QuoteOr contact us directly: 07826 705389 •