Double Storey Extension Architect in Frognal
Matching service for homeowners seeking independent ARB-registered architects for double storey extension projects in Frognal.
Two-storey rear or side extension adding significant floor space. In Frognal, brief quality and local planning constraints usually define how fast projects move.
Typical delivery timeframe for build works is 16-24 weeks, with design and approvals running before construction starts.
Frognal has conservation context, so proposals often need more careful external design rationale.
Double Storey Extension in Frognal: what to know
Double Storey Extension projects in Frognal need to balance the homeowner's spatial ambitions with the practical constraints of the existing building and its setting. In NW3, where housing ranges from georgian houses to edwardian houses, extension design must respond to plot depth, boundary distances, and the relationship with neighbouring properties. The typical delivery timeline of 16-24 weeks for construction reflects the technical complexity involved, but design and approvals add further months before building work begins. Getting the brief right at the outset — defining exactly what the extension needs to achieve and how it integrates with the rest of the house — is what separates projects that add genuine value from those that simply add square footage.
Planning permission is likely required for double storey extension in Frognal. The Hampstead Village conservation area adds a layer of design scrutiny to external alterations — the planning authority assesses proposals for their impact on local character, streetscape, and the setting of neighbouring buildings. Almost always requires planning permission In practice, this means that material choices, roof forms, window proportions, and the visual relationship between new and existing elements all receive careful review. Architects with conservation area experience in Frognal know how to present proposals that satisfy these requirements while still delivering the functional improvements homeowners need.
With average property values around £2150K in Frognal, the investment case for well-designed double storey extension is clear — quality architectural work adds both financial value and daily living quality. Adding at both ground and first floor levels requires careful design to manage the visual impact on neighbours and the streetscape. The georgian houses in Frognal present specific massing considerations that an experienced architect can resolve through thoughtful roof design and setbacks. We match homeowners in Frognal with architects who have delivered comparable double storey extension projects locally, ensuring that the practical realities of working with NW3 properties are understood from the outset.
Cost overview
| Band | Typical range |
|---|---|
| Budget | 5–8% of build cost |
| Mid | 8–12% of build cost |
| Premium | 12–15%+ of build cost |
Indicative ranges based on typical RIBA-stage architect fees. Actual fees depend on project scope and complexity.
See detailed double storey extension costs in Frognal →Planning requirements
Almost always requires planning permission
Because Frognal includes conservation controls, external appearance and massing often receive tighter review.
Check planning requirements for double storey extension in Frognal →Process timeline
- Scope and briefing aligned to your priorities and constraints.
- Concept options reviewed against planning route and budget.
- Design development and approvals strategy finalised.
- Technical package prepared for pricing and delivery.
- Construction phase support and coordination as needed.
Frequently asked questions
Almost always requires planning permission. Local context in Frognal can change the route, so early design review is important.
Related projects in Frognal
Rear Extension
Typical duration: 10-16 weeks
Planning: depends
Loft Conversion
Typical duration: 8-12 weeks
Planning: depends
Same area, other services: Architect in Frognal
Discuss your double storey extension project in Frognal
We match your brief with independent ARB-registered architects suited to this project type and area context.
Architect Hampstead is a matching service operated by Hampstead Renovations Ltd. We are not an architecture practice.
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