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Flat 1D, Block 1 Portman Mansions, Chiltern Street, London, W1U 5AJ

UPRN:10033532069Purpose Built Flat3 bedsBuilt before 1900
LeaseholdCouncil Tax: -EPC: C (76)
Data freshness:Listing· 2mo agoListing: ageing, refreshed 2mo ago (2026-09-20T04:00:03.031754+00:00)Planning· 3mo agoPlanning: ageing, refreshed 3mo ago (2026-08-13T09:13:53.444969+00:00)Ownership· freshOwnership: fresh, refreshed 3d ago (2026-11-06T17:34:01.679477+00:00)EPC· 6mo agoEPC: stale, refreshed 6mo ago (2026-05-20T10:58:39.129138+00:00)Risk· 5mo agoRisk: stale, refreshed 5mo ago (2026-06-18T00:00:00+00:00)Connectivity· 1mo agoConnectivity: ageing, refreshed 1mo ago (2026-10-03T06:43:10.905825+00:00)Schools· 1mo agoSchools: ageing, refreshed 1mo ago (2026-10-06T08:24:30.427161+00:00)Amenities· 2mo agoAmenities: ageing, refreshed 2mo ago (2026-09-23T00:00:00+00:00)Area· Census 2021Area: static reference data (Census 2021); authoritative and does not refresh
Flat 1D, Block 1 Portman Mansions, Chiltern Street, London, W1U 5AJ

HP Score

Mixed
Verdict
3 days ago
  • Verdict: INVESTIGATE, on a scale of Buy, Investigate, Avoid.

    Mixed signals - investigate

Evidence
20 of 21 sources
Sale Estimate
£1,539,000
£1.39M - £1.69MMedium
Estimate
£1.54M
Range
£1.39M – £1.69M
Rent Estimate (pcm)
£4,750
£4k - £5k
Monthly
£4,750
Yield
3.70%

Verdict

Derived from HomePortfolio scores

Flat 1D earns an INVESTIGATE rating with HP Score 68/100. Investment score 79/100 reflects strong fundamentals. Crime intensity is elevated. Walkability is excellent (100/100). Flood risk is not assessed: check the Environment Agency long-term flood map before offering. Tenure is leasehold. Every figure here comes from the live HomePortfolio API; anything it does not publish is left out.

Key SourcesEPC RegisterPortal listingsOfcom Connected NationsOfcom mobile coverageMarket estimates (third-party AVM)HM Land Registry sales matched to addressDefra strategic noise mapping, England Round 4 (Contains Defra data © Crown copyright and database right 2023-2024, Open Government Licence v3.0)Walk ScoreONS Census 2021Police.ukHM Land Registry company ownershipHM Land Registry covenantsHM Land Registry leasesHM Land Registry Price PaidPlanIt / council planning portalsOverture Maps PlacesOfsted / DfE GIAS
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HP Score
68/ 100
Mixed
Investment Score
79/ 100
High
Crime Score
100/ 100
Elevated
Walkability
100/ 100
Excellent
Transit & Bike
Transit 100Bike 71
Walk Score, out of 100

Valuation & Market

Sale Estimate£1,539,000
Rent Estimate (pcm)£4,750
Gross Yield3.70%
1y Growth-
3y Growth-6.2%
5y Growth-2.6%
10y Growth-1.3%
Last Sold Price£850,000 (2009-08-11)
View Market Details

Risk Overview

  • Flood RiskUnknown
  • SubsidenceSignificant
  • RadonLow
  • MiningUnknown
  • LandslideLow
  • Air QualityLow
  • NoiseModerate
View Full Risk Report

Planning Activity

Recent Apps
1W1U 5AJ
Approval Rate
-12mo
Development
low
  • 26/07416/LBC
    Amalgamation of Flats 3 and 4 to form one single dwelling including associated internal reconfiguration and refurbishments, alterations to access arrangements and improvements to the existing terrace and private amenity spaces. Together with the removal and alteration of modern partitions, roof replacement, rebuilding of the roof terrace, new plant and addition of a new staircase, structural works, new window openings, and other associated works. (Linked with 26/07415/FULL)
    Pending
  • 26/07415/FULL
    Amalgamation of Flats 3 and 4 (Use Class C3) to form one single dwelling (Use Class C3) including associated internal reconfiguration and refurbishments, alterations to access arrangements and improvements to the existing terrace and private amenity spaces, new plant and other associated works. (Linked with 26/07416/LBC)
    Pending
  • 26/07390/LBC
    Installation of a non-illuminated fascia sign measuring 0.29m x 0.79m and two vinyl signs applied to inside face of the glazed shopfront each measuring 0.22m x 0.84m. (Linked with 26/06970/ADV)
    Pending
View Planning Timeline

Ownership

  • Corporate Ownership15.2%
  • Overseas OwnershipNo
  • Lease Term Remaining999+ yrs
  • CovenantsRestrictive
  • Lease TypeLeasehold
  • Last Ownership Change2009-08-11
  • SourceLand Registry
View Ownership Details

Connectivity

Broadband (Standard)
18 Mbps
Mobile 4G/5G Coverage
EEThreeO2Vodafone
EV Charger
-
PTAL Rating
-
View Connectivity Map

Area Profile

Median EarningsLocal authority£45,172
Population Density14,432 /km²
Owner Occupied36%
Age Distribution
0-15 10%16-64 76%65+ 14%
View Area Profile

Schools Nearby

  • Francis Holland School
    0.2 mi
    Inspected by ISI
  • The St Marylebone CofE School
    0.2 mi
    Area grades2025

    Inspected after Ofsted withdrew the single overall grade.

  • ICS London
    0.3 mi
    Inspected by ISI
  • Royal Academy of Music
    0.3 mi
    -

4 of 6 nearby schools with published figures were oversubscribed in 2026 - demand, not a catchment.

View All Schools

Comparables

View All
  • Portman Mansions Chiltern Street
    -
    £1.57M
    -
  • Portman Mansions Chiltern Street
    -
    £1.43M
    -
  • Portman Mansions Chiltern Street
    -
    £1.15M
    -
  • Portman Mansions Chiltern Street
    -
    £985k
    -