Borough Report

Merton

320 determined applications · 20 wards · 5 areas · 29 conservation areas · 2023–2025

Get the report → Download free Snapshot first

Headline findings

42%
Schemes compressed
Highest compression rate in our dataset
Verified
2+
New H11.1 threshold
20% AH in-lieu from just 2 units (Nov 2024)
Verified
−26%
10th unit cliff
Per-unit residual drops at full AH obligation
Verified
38%
Refusal rate
123 of 320 decided small-site applications
Verified

Key findings

Verified 42.3% of schemes compressed — highest in our dataset, propose N+2 minimum ›
42.3% of approved schemes are compressed during determination, with an average loss of 2.0 units (median 1). This is the highest compression rate across all seven boroughs in our dataset. Strategy: propose at least 2 additional units above your target with design flexibility for removal. n=182 approved applications with proposed and approved counts.
Verified New H11.1 creates a 2-unit cliff: −25% per-unit residual from just 2 units ›
Merton’s new Local Plan (adopted 20 November 2024) introduces H11.1: 20% affordable housing in-lieu contribution from just 2 units. Per-unit residual drops 25% from £159k (1-unit safe harbour) to £120k at 2 units. The 1-unit scheme is the only AH-exempt format. This fundamentally changes every small-site land bid in the borough.
Verified The 6-unit sweet spot: £120k/unit residual, delegated, zero committee exposure ›
Six units delivers the optimal per-unit residual (£120,000) with delegated determination. At 10 units, full 35% on-site AH obligation triggers a further 26% collapse. The double cliff (2-unit H11.1 + 10-unit full obligation) makes Merton’s viability landscape uniquely challenging.
Indicative Pre-app does not improve approval rate — it buys certainty, not speed ›
Counter-intuitively, pre-app engagement in Merton is associated with a lower approval rate (48.4% vs 51.1% without). Pre-app adds 21 days to determination (p=0.002). This likely reflects selection bias: complex, contested sites self-select into pre-app. Budget pre-app for genuinely complex proposals where risk reduction justifies the time cost. n=272.
Verified Conservation area penalty is extreme: −50% density (p<0.00001) ›
Sites in conservation areas achieve dramatically lower density: 41.4 u/ha median vs 82.5 u/ha outside — a 49.9% gap. The effect is the strongest in our dataset (p<0.00001, Mann-Whitney U). With 29 CAs covering 17% of applications, heritage constraints materially compress achievable yield. n=320.
Verified West–East CIL gradient: £432/m² (Wimbledon) vs £260/m² (Mitcham) indexed ›
Zone 1 (Wimbledon, Raynes Park, Colliers Wood): £220/m² base + £60 MCIL2 = ~£432/m² indexed. Zone 2 (Mitcham, Morden, West Barnes): £115/m² + £60 = ~£260/m² indexed. The 66% CIL differential makes eastern sites materially cheaper to develop.
Verified 38.4% refusal rate with zero appeals lodged across entire dataset ›
123 of 320 decided applications are refused. Zero appeals were lodged, meaning the appeal route is entirely unused for small sites in Merton. Mitigants: rigorous space standards compliance, heritage-sensitive design in CAs, and realistic density expectations informed by the P75 benchmark. n=320.

Plus additional findings covering ward-level patterns, officer tendencies across 33 officers, committee vs delegated benchmarks, amenity impact, density benchmarks by site type, and determination time. Each graded Robust, Moderate, Indicative, or Anecdotal.

What you get

The full report

  • 53-page report (HTML & PDF) with 21+ evidence-graded findings
  • Density matrix by site type with P20–P75 ranges
  • PTAL-adjusted density lookup table
  • Viability model with cliff chart and sensitivity analysis
  • Ward-level and area-level approval rate maps
  • Refusal reason analysis with frequency data
  • Conservation area risk assessment (29 CAs)
  • Case officer patterns across 33 officers

Merton-specific insights

  • New H11.1 policy impact: AH from 2 units (Nov 2024)
  • Double cliff analysis: 2-unit + 10-unit thresholds
  • 42.3% compression rate — N+2 strategy essential
  • Conservation area penalty quantified (p<0.00001)
  • 2-zone CIL: £220/m² (West) / £115/m² (East) + £60 MCIL2

Decision tools

  • Before-you-bid and before-you-submit checklists
  • One-page Market Snapshot for quick reference
  • Underlying data in Excel for your own analysis

Get the report

Borough Intelligence Reports from £1,500. Includes 12 months of free quarterly updates.

View pricing →

Reports delivered via the members’ platform. Includes HTML & PDF report, Excel data, and Market Snapshot.

Want to see the data before you buy?

Download the free Merton Market Snapshot. Five findings, one page, no commitment.

Download free Market Snapshot → See all boroughs