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Borough Guides11 min read • Updated Oct 2025

Hackney Extension Guide 2025: Planning Rules, Costs & Tips

Complete guide to extending your home in Hackney. New SPD guidance, planning permission requirements, conservation area rules, and typical costs.

Hackney Extensions: Quick Facts

  • Cost: £2,000-2,900/m² typical (add 10-15% in conservation areas)
  • New SPD: 2025 Residential Extensions guidance replaces 2009 rules
  • Planning: 8 weeks standard, 10-16 weeks for complex applications
  • Conservation areas: 29 across Hackney with Article 4 restrictions
  • Get your Hackney extension estimate (Free)

New Planning Guidance for Hackney (2025)

Hackney adopted a new Residential Extensions and Alterations SPD in 2025, replacing the 2009 guidance. This updated policy provides clearer rules on extension design, sustainability requirements, and how to reflect Hackney's diverse local character.

The borough has 29 conservation areas covering areas like Stoke Newington, Dalston, De Beauvoir Town, and parts of Hackney Central. Many of these areas have Article 4 directions that remove permitted development rights.

Permitted Development Rights in Hackney

Standard permitted development rules apply outside conservation areas and Article 4 direction zones:

Extension TypeMax Without PermissionHackney Notes
Single-storey rear (detached)6m deep, 4m highCheck for Article 4 directions first
Single-storey rear (semi/terrace)3m deep, 4m highVery limited in conservation areas
Side extensionHalf width of housePlanning required in most areas
Two-storey rear3m deep maxAlmost always needs permission
BasementN/AAlways requires planning permission

Key Restrictions

  • All 29 conservation areas have some planning restrictions
  • Article 4 directions in Stoke Newington, Dalston, De Beauvoir remove PD rights
  • Listed buildings always require listed building consent

Check your Hackney planning constraints

Instantly see conservation areas, Article 4 directions, and tree preservation orders.

Check Planning Constraints →

Design Requirements Under New SPD

The 2025 Residential Extensions SPD emphasizes design quality, local character, and sustainability.

Key Design Principles

  • Respect local character: Match materials, proportions, and details of surrounding properties
  • Sustainability: Energy efficiency, sustainable materials, rainwater management
  • Neighbor amenity: Minimize impact on light, privacy, and outlook
  • Garden retention: Preserve outdoor amenity space and biodiversity

Extension Costs in Hackney

Extension TypeCost per m²Typical Total
Single-storey rear (20m²)£2,000-2,600£40,000-52,000
Side return (12m²)£2,500-3,400£30,000-41,000
Two-storey rear (40m²)£2,200-2,900£88,000-116,000
Loft conversion (30m²)£1,800-2,500£54,000-75,000
Basement (40m²)£2,900-3,900£116,000-156,000

Conservation area premium: Add 10-15% for matching materials and heritage details

Additional Costs

  • Architect fees: £4,000-11,000 (10-15% of build cost)
  • Structural engineer: £1,500-3,500
  • Planning application: £206 (householder) or £462 (full planning)
  • Party wall: £1,500-3,000 per neighbor
  • Building Control: £800-2,000

Get Your Hackney Extension Estimate

Instant cost breakdown including Hackney-specific requirements and conservation area premiums.

Free • Instant results • No email required

Frequently Asked Questions

Do I need planning permission for an extension in Hackney?

It depends on your property type and location. Standard permitted development allows single-storey rear extensions up to 6m (detached) or 3m (terraced/semi). However, Hackney has 29 conservation areas and extensive Article 4 directions in areas like Stoke Newington, Dalston, and De Beauvoir Town. Always check planning constraints before starting design work.

How much does an extension cost in Hackney?

Extension costs in Hackney: £2,000-2,600/m² for single-storey rear extensions, £2,200-2,900/m² for two-storey extensions, £2,500-3,400/m² for side returns, and £2,900-3,900/m² for basements. Conservation area projects add 10-15% for matching materials. Total costs range from £40k for small single-storey to £200k+ for basements.

What is Hackney's new residential extensions SPD?

Hackney adopted a new Residential Extensions and Alterations SPD in 2025, replacing the 2009 guidance. It provides updated rules on extension design, sustainability requirements, and how to reflect local character. The SPD supports policies in Hackney's Local Plan and applies to all residential extension applications from 2025 onwards.

How long does planning permission take in Hackney?

Standard planning applications take 8 weeks in Hackney. Conservation area and Article 4 direction areas may take 10-13 weeks due to additional consultation. Complex applications (basements, multiple storeys) can take 12-16 weeks. Pre-application advice costs £150-500 and is recommended for conservation area properties. Check planning timelines for details.