Maritime Greenwich World Heritage Site brings extra scrutiny. 20 conservation areas, 6 with Article 4 directions. Side return £55k-90k, rear £65k-95k. Victorian/Edwardian mix.
TL;DR - The Quick Answer
Greenwich has 20 conservation areas, with 6 carrying Article 4 directions that remove permitted development rights and require planning permission for most extensions. The Maritime World Heritage Site adds scrutiny in central areas but affects fewer homes than expected. Around 55% of residential properties sit outside these restricted zones and benefit from standard permitted development rules. Extension costs run £1,800-2,500/m², roughly 10-15% below central London rates.
Greenwich differs from most London boroughs due to the Maritime Greenwich World Heritage Site designation covering central Greenwich. This UNESCO designation adds an extra layer of planning scrutiny, but affects fewer residential properties than you might think.
| Area Type | Coverage | Impact on Extensions |
|---|---|---|
| World Heritage Site core | ~5% of residential properties (around Greenwich Park/Naval College) | Very high scrutiny Extensions rarely visible from WHS Historic England consulted |
| WHS buffer zone | ~15% of residential (East/West Greenwich, parts of Blackheath) | Moderate scrutiny Must not harm WHS setting Design sensitivity required |
| Conservation areas (outside WHS) | ~25% of residential (Blackheath, Westcombe Park, Charlton) | Standard conservation area rules 6 areas have Article 4 directions |
| No designations | ~55% of residential (Plumstead, Woolwich, Eltham, Thamesmead) | Standard permitted development rights apply Least restrictive |
55% of Greenwich residential properties are outside conservation areas and World Heritage Site zones. These areas have standard permitted development rights and are among the least restrictive in London.
Areas like Plumstead, Woolwich, Eltham, and Abbey Wood offer good extension opportunities without heavy conservation restrictions.
According to TrustedBuilders 2025 Greenwich cost data, extensions cost £1,800-2,500/m² - South London mid-range pricing (cheaper than central London, more expensive than outer suburbs).
| Extension Type | Typical Size | Cost Range (£/m²) | Total Cost |
|---|---|---|---|
| Side return (basic) | 10-12m² | £1,800-2,200 | £55,000-70,000 |
| Side return + kitchen refurb | 10m² ext + 20m² refurb | £2,200-2,800 (blended) | £85,000-110,000 |
| Single storey rear (3m) | 18-22m² | £1,800-2,400 | £65,000-85,000 |
| Single storey rear (6m) | 36-42m² | £1,800-2,300 | £75,000-100,000 |
| Wrap-around (side + rear) | 40-50m² | £2,000-2,500 | £110,000-140,000 |
| Two storey rear | 40-50m² | £2,200-2,800 | £130,000-165,000 |
| Loft conversion (dormer) | 25-35m² | £1,500-2,000 | £45,000-65,000 |
| Extension Type | Typical Size | Cost per m² | Total Cost |
|---|---|---|---|
| Side return (basic) | 10–12m² | £1,800–2,200 | £55,000–70,000 |
| Single storey rear (3m) | 18–22m² | £1,800–2,400 | £65,000–85,000 |
| Single storey rear (6m) | 36–42m² | £1,800–2,300 | £75,000–100,000 |
| Wrap-around (side + rear) | 40–50m² | £2,000–2,500 | £110,000–140,000 |
| Two storey rear | 40–50m² | £2,200–2,800 | £130,000–165,000 |
| Loft conversion (dormer) | 25–35m² | £1,500–2,000 | £45,000–65,000 |
Source: TrustedBuilders / Mayfair Studio Greenwich project data • Data as of 2025
More builders active in SE London, increasing competition and lowering rates vs central London monopolies
Better parking/access for delivery vehicles reduces material handling costs. Less restrictive parking enforcement than Zone 1.
More space around properties (less dense than central) = easier scaffolding = lower costs (£1,200-1,800 vs £2,000-3,000 central)
Outside conservation areas, modern materials acceptable = 10-15% cost saving vs mandated traditional materials
According to Royal Greenwich planning controls guidance, permitted development rules apply borough-wide except in conservation areas with Article 4 directions.
| Property Type | Rear Extension (No Prior Approval) | Rear Extension (With Prior Approval) |
|---|---|---|
| Terraced/semi-detached | Up to 3m depth Max 4m height Max 3m at boundary | Up to 6m depth Same height limits £96 fee, 6 weeks |
| Detached house | Up to 4m depth Max 4m height Max 3m at boundary | Up to 8m depth Same height limits £96 fee, 6 weeks |
Royal Greenwich has Article 4 directions in 6 out of 20 conservation areas, affecting approximately 10% of borough residential properties. These remove permitted development rights for:
Check if your property has Article 4 restrictions: Royal Greenwich Article 4 Direction Map
The Maritime Greenwich World Heritage Site designation sounds intimidating, but in practice affects relatively few residential extension projects:
Includes: Properties immediately surrounding Greenwich Park, Royal Naval College, Queen's House
Impact: Extensions must not be visible from WHS landmarks. Historic England consulted on all applications.
Reality: Most residential extensions are to rear (not visible from park/landmarks). Front extensions or roof extensions face very high scrutiny.
Includes: East Greenwich, West Greenwich, parts of Blackheath
Impact: Design must respect "setting" of WHS. Traditional materials encouraged.
Reality: Standard rear extensions usually approved. Two-storey or highly visible extensions require more justification.
Includes: Plumstead, Woolwich, Eltham, Abbey Wood, Thamesmead, Charlton
Impact: Zero WHS considerations
Reality: Standard London planning rules apply. Easiest areas in Greenwich for extensions.
Greenwich has high proportion of Victorian and Edwardian terraced housing, particularly in:
| Application Type | Fee | Decision Time |
|---|---|---|
| Householder (full planning) | £206 | 8 weeks (target) |
| Prior approval (larger permitted development) | £96 | 6 weeks |
| Pre-application advice | £150-350 (size dependent) | 4 weeks |
Cost: £150-350
Especially valuable for WHS buffer zone or conservation area properties. Officer indicates if design likely to be approved.
Required Documents:
Timeline: 1-2 weeks validation + 21 days neighbor consultation
If in WHS buffer: Historic England consulted (adds no time, consultation runs parallel)
Target: 8 weeks
Reality: 8-10 weeks typical. WHS applications not significantly slower than non-WHS.
Terraced properties in East/West Greenwich, Blackheath, and Charlton require party wall agreements for most extensions:
| Extension Type | Party Wall Required? | Typical Cost |
|---|---|---|
| Side return (on boundary) | ✅ Yes (one or both sides) | £1,200-2,000 per side |
| Rear extension (within boundaries) | ⚠️ If foundations within 3m of boundary | £800-1,500 per side |
| Loft conversion | ✅ Yes (both neighbors) | £1,200-1,800 (both sides) |
Greenwich extensions cost £1,800–2,500/m², around 10–15% less than central London. The borough has 20 conservation areas but only 6 carry Article 4 directions. Around 55% of residential properties sit outside all restricted zones, giving full permitted development rights. Side returns cost £55,000–90,000 and rear extensions £65,000–95,000 inc VAT.
No, not for most residential extensions. Only ~5% of Greenwich homes are in the WHS core where restrictions are severe. Another 15% are in the buffer zone with moderate scrutiny. The remaining 80% of Greenwich residential properties have no WHS restrictions. Standard rear extensions are routinely approved even in buffer zones.
Side return: £55,000-70,000 (extension only) or £85,000-110,000 with full kitchen refurbishment. Single storey rear 3m: £65,000-85,000. Wrap-around: £110,000-140,000. These costs are 10-15% lower than central London due to better builder competition and access.
In all conservation areas, the Prior Approval route for larger rear extensions (up to 6m/8m) is not available, regardless of whether an Article 4 direction applies. Standard PD rear extensions (3m terraced/semi, 4m detached) are still permitted unless an Article 4 direction removes them. Greenwich has 20 conservation areas, and 6 have Article 4 directions that remove additional PD rights. Side extensions and most dormers need planning permission in any conservation area. Check Royal Greenwich's Article 4 map for your specific property.
Plumstead, Woolwich, Eltham, Abbey Wood, and Thamesmead have fewest restrictions. These areas are outside conservation areas and World Heritage Site zones, have full permitted development rights, and councils generally more flexible on modern designs and materials. Approx 55% of Greenwich residential properties fall in these easier categories.
Yes if: (1) in World Heritage Site buffer zone, (2) in conservation area, or (3) proposing two-storey/large extension. Cost: £150-350. Benefits: find out if design acceptable before spending £2,000-4,000 on full drawings, speeds up main application. Not essential if: outside conservation area + standard single-storey rear extension within permitted development limits.
Target: 8 weeks (56 days). Reality: 8-10 weeks typical for straightforward cases. WHS buffer zone applications don't take significantly longer (Historic England consultation runs parallel to standard process). Conservation area applications may take 10-12 weeks if amendments required.
World Heritage Site Reality: Only 5% of residential properties in WHS core with severe restrictions. 15% in buffer zone (moderate scrutiny). 80% have no WHS restrictions. Less scary than it sounds.
Cost Advantage: £1,800-2,500/m² average = 10-15% cheaper than central London. Side return £55k-90k, rear extension £65k-95k. Good value for South London.
Conservation Areas: 20 total, but only 6 have Article 4 directions. Check map before assuming you need planning permission.
Best Areas: Plumstead, Woolwich, Eltham = minimal restrictions, full permitted development rights, modern designs accepted. 55% of borough falls in this category.
Bottom Line: Greenwich is more extension-friendly than reputation suggests. Outside WHS core and conservation areas with Article 4, standard London planning rules apply. Costs reasonable for location. Victorian terraced housing perfect for side returns and loft conversions.
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