💡 Don't move, Improve (AL it)
Find out what your extension is really worth
Planning permission granted by South Holland District Council in nine weeks on a flood-designated site, with the Flood Risk Assessment produced in-house.
From 3 Bedrooms to 5: an Approved Rear + Two Storey Side Extension in Holbeach
Project facts bar
- Location: Holbeach, South Holland, Lincolnshire
- Project type: Single storey rear extension + two storey side extension
- The transformation: 3 bedrooms → 5 · 110 m² → 157 m² (+47 m²) · new 20.6 m² kitchen/living with rooflights · 16 m² home office · utility, boot room and two new shower rooms
- Services provided: Feasibility, full planning drawings (Revit/BIM), planning application as agent, in-house Flood Risk Assessment, 3D visualisation
- Council & outcome: South Holland District Council — planning permission granted, February 2026
- Timeline: Survey November 2025 → submission December 2025 → approval February 2026
- Estimated value added: £187,150
The story
The situation
A family home in Holbeach, Lincolnshire. Big Fenland skies, a quiet lane, and a three-bedroom house that the family had simply outgrown. Cooking, working from home, and everyday life were all competing for the same rooms. Moving would have meant leaving the lane they loved and paying six figures in stamp duty, fees and a bigger mortgage for the privilege. The brief to AL-Haitham Ltd was the one we hear most.
don't move, improve.
The challenge
Most architects' plans stop where the Environment Agency's flood map begins and this site sits squarely in a flood-designated part of the Fens. It's protected by defences, with less than a 0.1% chance of flooding in any year, but the council still expects the risk to be designed for, not mentioned in passing. Instead of sending the client to a third-party consultant for a separate report (more weeks, more fees), we produced the Flood Risk Assessment in-house and built the resilience into the construction itself: a finished floor level set above external ground, sealed glazing, lapped damp-proofing, lime-based plaster, stainless steel wall ties, and electrical services routed through ceilings and walls rather than floors. The scheme itself was deliberately disciplined a full-width rear extension held to 3.5m deep, and a side extension kept to less than half the width of the original house. So it arrived at the planning desk already speaking the council's language.
The solution & result
The design went through three iterations with the family between November and December 2025. Every version modelled in Revit, so they could walk the house on screen, not decode drawings. The approved scheme rebuilds how the ground floor works: a new 20.6 m² kitchen/living space across the rear, lit by rooflights and opening to the garden; a proper 16 m² home office; a utility room, boot room and ground-floor shower room where muddy boots and laundry belong. Upstairs, the two storey side extension takes the house from three bedrooms to five, adds a second shower room, and keeps the family bathroom. South Holland District Council granted permission in nine weeks. 110 m² becomes 157 m², and the estimated value added is £187,150 against a build that costs a fraction of moving.
The evidence
Planning an extension in Holbeach, South Holland District Council?
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