A structural alteration changes how the building carries load, whether that is a new opening, a removed wall, a supported chimney breast or an altered roof. We survey, appoint a structural engineer, build to the calculations issued and coordinate the approvals. Letchworth Garden City is unusual because two separate consents can apply to the same job. This page sets out both, and the ground underneath them.
Letchworth has two consent regimes, and one of them is private
The Heritage Foundation Scheme of Management is a legal agreement applying to all freehold properties within the Letchworth Garden City estate, and it sits alongside the council's planning role rather than replacing it. That is the second regime, and it is a private covenant rather than a planning control.
The Letchworth Garden City Heritage Foundation is constituted under the Letchworth Garden City Heritage Foundation Act 1995, a local Act cited as 1995 c. ii. That Act transferred the undertaking from the former corporation and created the office of the Letchworth Commissioner. An alteration that shows on the outside therefore has two decision makers on two separate timetables, and the order you approach them in affects the programme.
What the adopted Local Plan tests an alteration against
Policy D2 of the adopted North Hertfordshire Local Plan grants permission for house extensions only where two tests are both met. The work must be sympathetic to the existing house in height, form, proportions, roof type, window details, materials and the orientation of the main dwelling. It must also not dominate adjoining properties.
Policy HE1 requires any planning application relating to a designated heritage asset or its setting to be accompanied by a Heritage Assessment or Justification Statement. That is a document to commission early, because it goes in with the application rather than in answer to a query. We tell you at quotation stage which consultants your scheme needs and where they sit in the programme.
Chalk bedrock, with the Lowestoft Formation over it
British Geological Survey mapping shows the bedrock under central Letchworth as the Holywell Nodular Chalk Formation and New Pit Chalk Formation, undifferentiated. The same mapping shows the Lowestoft Formation, a chalky glacial till classified as diamicton, as the most extensive superficial deposit across the town. It covers central, southern and south eastern parts, including the Jackmans Estate.
Along the far western edge no superficial deposit is mapped, so chalk lies at or near the surface there. That distinction matters where an alteration puts new load onto new foundations. What a pier or a pad bears on is a question to settle before the steel is ordered, not after it arrives. We record what is exposed and pass it to the structural engineer.
What happens if Foundation consent is refused, or never applied for
A refused Heritage Foundation application can be appealed to an Independent Inspector, an architect nominated by RIBA, within 12 weeks of the date of the final decision letter. The standard fee is £550 including expenses, shared equally between the applicant and the Foundation, and the decision binds the Foundation. The case must have been through the Advisory Management Committee and the Householders Application Committee first.
Skipping the application is the more expensive route. The Foundation warns that altering a home without its written consent breaches the Scheme of Management or the lease. It states that this could result in difficulties when coming to sell the property, and in legal action being taken by the Heritage Foundation.
- Chimney breast removal and support to the stack above
- Load paths carried down to foundations on new piers and pads
- Load-bearing wall removal and new structural openings
- Reinstatement, plastering and finishing after structural works
- Lintel replacement and repair over failed openings
Why Letchworth Garden City Homeowners Choose GS Renovation
The value we add on a Letchworth structural alteration is sequencing. Two consents can apply to one job, the engineer has to be appointed before either can be answered properly, and the building control inspections sit inside the build rather than at the end of it. We appoint and coordinate structural engineers and build to their calculations. We are a contractor, not a surveyor or an architect, and we never produce structural calculations ourselves. GS Renovation Ltd is registered in England, company number 14611254, and fully insured. Quotations are free and carry no obligation.
- A dedicated project manager from first survey to handover
- Building control inspected at foundation, steel and completion
- Clean, tidy and reliable tradespeople
- Load paths carried properly down to foundations
- Waste cleared as we go, not left piled in the garden
- Photographs kept at each stage for your records