21 Lyme Avenue, Northchurch, Berkhamsted, HP4 3SG

UPRN:100080677136Semi-Detached House4 bedsBuilt 1930-1949

FreeholdCouncil Tax: Band DEPC: E (49)

Data freshness:Listing· freshEPC· 6mo agoRisk· 5mo agoConnectivity· 1mo agoSchools· 1mo agoAmenities· 2mo agoArea· Census 2021

21 Lyme Avenue, Northchurch, Berkhamsted, HP4 3SG

HP Score

/ 100

Mixed

Verdict

5 days ago

Verdict: INVESTIGATE, on a scale of Buy, Investigate, Avoid.
Mixed signals - investigate

Evidence

18 of 21 sources

Sale Estimate

£613,000

£552k - £675kMedium

Estimate

£613k

Range

£552k – £675k

Rent Estimate (pcm)

£1,850

£2k - £2k

Monthly

£1,850

Yield

2.79%

Verdict

Derived from HomePortfolio scores

21 Lyme Avenue earns an INVESTIGATE rating with HP Score 68/100. Investment score 53/100 reflects moderate fundamentals. Crime intensity is very low. Walkability is limited (31/100). Flood risk is not assessed: check the Environment Agency long-term flood map before offering. Tenure is freehold. 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 covenantsHM Land Registry Price PaidPlanIt / council planning portalsOverture Maps PlacesOfsted / DfE GIAS

HP Score

68/ 100

Mixed

Investment Score

53/ 100

Moderate

Crime Score

14/ 100

Low

Walkability

31/ 100

Mixed

Transit & Bike

Transit 9Bike 21

Walk Score, out of 100

Opportunity

Why this could be an opportunity

Low confidence0 independent sourcesListing checked 2 Nov 2026

This rests largely on a single source. Treat the score as a prompt to investigate, not a conclusion.

Valuation edge-0.6/15
claims [AVM -29.7% (MEDIUM), sold-comps -40.0%, £/sqft -39.9%] → measured edge -0.12pp of the ask; on later-registered sales an AVM discount carried no edge and a sold-evidence gap at most +0.5pp; asking more than 10% above the estimate (measured -0.33pp)
Market estimate used (MEDIUM confidence) · snapshot 12 Oct 2026
- valuation_snapshotsestimate for 100080677136· as of 12 Oct 2026
- property_comparablessold-evidence family (implied value + £/sqft): 12 comps, dispersion 16.9%· as of 28 Oct 2026
Rental economics0/40
gross yield 2.8%; range width penalty ×0.71
- valuation_snapshotsrent estimate 1850/mo (range 1650-2100)· as of 12 Oct 2026· verify before relying on this
Stress margin0/30
stressed cash flow -2,124/mo, -115% of rent (6.75% on a 75% loan; no service charge or ground rent disclosed); fails the stress - earns nothing
- underwriting_assumptionscosts not disclosed by the advert· as of 2 Nov 2026
Seller motivationNot scored
context, not scored: 0 price cut(s), 29 days on market; homes with a cut sold 0.2-0.3pp further below the cut ask, which is not an edge
- portal_listingsprice_changes + first_published_date· as of 2 Nov 2026
Risk & liquidity12.8/15
242 sales/12mo in area; valuation range width 20%
- property_intelligencetransactions_12mo

4 of 4 components scored. Ranks on gross yield, the stress margin, risk and disclosed facts. A pricing claim earns only its measured edge: today 0 for the market estimate and at most +0.5pp for sold evidence. The score itself is not yet checked against the outcomes of homes it scored.

Economics

What happens to your money

Price sensitivity

£596,000£914,000

The same scorer re-run at hypothetical asking prices, holding rent, comps and listing history constant. Not a prediction of what the seller would accept.

Your assumptions

Purchase price£795,000

At the asking price

Monthly rent£1,850/mo

Evidenced range £1,650-£2,100

Interest rate5.4%

Loan to value75%

Cash required: £269,550
Net cash flow: -£1,402/mo
Cash on cash: -6.2%
Score at this price: 12

After a 8% void allowance, 15% management and 10% maintenance. Lender coverage (rent ÷ interest): 0.69 - below the usual 1.25 test. These are your assumptions, not evidence: only the pre-filled rent and price come from the record.

Evidence

Where every number comes from

valuation_snapshotsestimate for 100080677136Valuation edge · as of 12 Oct 2026
property_comparablessold-evidence family (implied value + £/sqft): 12 comps, dispersion 16.9%Valuation edge · as of 28 Oct 2026
valuation_snapshotsrent estimate 1850/mo (range 1650-2100)Rental economics · as of 12 Oct 2026 · verify before relying on this
underwriting_assumptionscosts not disclosed by the advertStress margin · as of 2 Nov 2026
portal_listingsprice_changes + first_published_dateSeller motivation · as of 2 Nov 2026

Risks

What could kill this deal

Score confidence is low
largely a single source - treat the number as a prompt, not a conclusion
Rental economics needs verification before you rely on it
rent estimate 1850/mo (range 1650-2100)
Seller motivation could not be scored
context, not scored: 0 price cut(s), 29 days on market; homes with a cut sold 0.2-0.3pp further below the cut ask, which is not an edge

Property risk deep-dive →

Plan

Before you offer

1. Get two written rental appraisals from local lettings agents.
The rent estimate rests on area-level evidence, not lettings on this street.
2. Commission a full structural survey, not a basic condition report.
The score prices market evidence, not the fabric of the building.

Every step above was generated from a specific gap or flag in the evidence - no generic advice, no invented tasks.

Valuation & Market

Sale Estimate£613,000

Rent Estimate (pcm)£1,850

Gross Yield2.79%

1y Growth-

3y Growth+2.1%

5y Growth+1.6%

10y Growth+2.6%

Last Sold Price£430,000 (2019-01-29)

View Market Details

Risk Overview

Flood RiskUnknown
SubsidenceModerate
RadonModerate
MiningSignificant
LandslideLow
Air QualityLow
NoiseLow

View Full Risk Report

Planning Activity

Recent Apps

1HP4 3SG

Approval Rate

100%12mo

Development

low

26/02423/FHA
Single storey rear extension, first floor side extension and loft conversion with front and rear dormers
Pending
26/02415/ROC
Variation of Condition 3 (Approved Plans) attached to planning permission 26/01793/FHA
Pending
26/02387/TEL
The proposed upgrade of an existing telecommunications base station comprising the removal of the existing 18 metre high tree mast and installation of a 23 metre high monopole with 6 no. antennas and 1 no. GPS module, and ancillary development thereto.
Pending

View Planning Timeline