21 Grantchester Road, Cambridge, CB3 9ED

UPRN:200004209254Detached House6 bedsBuilt 1967-1975

FreeholdCouncil Tax: Band GEPC: D (64)

Data freshness:Ownership· freshEPC· 6mo agoRisk· 5mo agoCrime· freshConnectivity· 1mo agoSchools· 1mo agoAmenities· 2mo agoArea· Census 2021Council Tax· 1mo ago

21 Grantchester Road, Cambridge, CB3 9ED

HP Score

/ 100

Mixed

Verdict

3 days ago

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

Evidence

19 of 21 sources

Sale Estimate

£1,852,000

£1.76M - £1.95MHigh

Estimate

£1.85M

Range

£1.76M – £1.95M

Rent Estimate (pcm)

£6,350

£6k - £7k

Monthly

£6,350

Yield

4.23%

Verdict

Derived from HomePortfolio scores

21 Grantchester Road earns an INVESTIGATE rating with HP Score 68/100. Investment score 59/100 reflects moderate fundamentals. Crime intensity is low. Walkability is limited (46/100). 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 company ownershipHM Land Registry covenantsHM Land Registry Price PaidPlanIt / council planning portalsOverture Maps PlacesOfsted / DfE GIAS

HP Score

68/ 100

Mixed

Investment Score

59/ 100

Moderate

Crime Score

31/ 100

Moderate

Walkability

46/ 100

Mixed

Transit & Bike

Transit 33Bike 85

Walk Score, out of 100

Opportunity

Why this could be an opportunity

Low confidence1 independent sourceListing checked 9 Nov 2026

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

Valuation edge2.5/15
claims [AVM +2.8% (HIGH), sold-comps +5.8%, £/sqft +5.8%] → measured edge +0.50pp of the ask; on later-registered sales an AVM discount carried no edge and a sold-evidence gap at most +0.5pp
Market estimate used (HIGH confidence) · snapshot 9 Nov 2026
- valuation_snapshotsestimate for 200004209254· as of 9 Nov 2026
- property_comparablessold-evidence family (implied value + £/sqft): 10 comps, dispersion 16%· as of 10 Nov 2026
Rental economics0/40
gross yield 4.2%; range width penalty ×0.74
- valuation_snapshotsrent estimate 6350/mo (range 5650-7100)· as of 9 Nov 2026· verify before relying on this
Stress margin0/30
stressed cash flow -3,056/mo, -48% 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 9 Nov 2026
Seller motivationNot scored
context, not scored: 0 price cut(s), 69 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 9 Nov 2026
Risk & liquidity14.6/15
91 sales/12mo in area; valuation range width 10%
- 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

£1,350,000£1,980,000

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£1,800,000

At the asking price

Monthly rent£6,350/mo

Evidenced range £5,650-£7,100

Interest rate5.4%

Loan to value75%

Cash required: £671,050
Net cash flow: -£1,679/mo
Cash on cash: -3.0%
Score at this price: 17

After a 8% void allowance, 15% management and 10% maintenance. Lender coverage (rent ÷ interest): 1.05 - 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 200004209254Valuation edge · as of 9 Nov 2026
property_comparablessold-evidence family (implied value + £/sqft): 10 comps, dispersion 16%Valuation edge · as of 10 Nov 2026
valuation_snapshotsrent estimate 6350/mo (range 5650-7100)Rental economics · as of 9 Nov 2026 · verify before relying on this
underwriting_assumptionscosts not disclosed by the advertStress margin · as of 9 Nov 2026
portal_listingsprice_changes + first_published_dateSeller motivation · as of 9 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 6350/mo (range 5650-7100)
Seller motivation could not be scored
context, not scored: 0 price cut(s), 69 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. Treat the gap to the estimate as unproven - compare recent sold prices on the street yourself before pricing an offer around it.
On later completions, homes listed below their estimate sold at the same share of the asking price as the rest.
3. 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£1,852,000

Rent Estimate (pcm)£6,350

Gross Yield4.23%

1y Growth-37.6%

3y Growth+3.5%

5y Growth-0.6%

10y Growth+0.4%

Last Sold Price£650,000 (2006-05-26)

View Market Details

Risk Overview

Flood RiskUnknown
SubsidenceLow
RadonLow
MiningLow
LandslideLow
Air QualityLow
NoiseLow

View Full Risk Report

Planning Activity

Recent Apps

6CB3 9ED

Approval Rate

50%12mo

Development

low

26/04168/HFUL
Two storey front and two storey rear extensions
Pending
26/04150/LBC
Replacement of all existing glazing to modern windows on the two upper floors including the attic including glazed doors to the ground floor of the front elevation of the complex changing from single glazing to double glazing using Fineo glass.
Pending
26/04155/LBC
Repair and conservation of the Piper Window and associated leadwork on the west elevation of the Grade II* listed main building at Robinson College. Works include localised repairs to the lead roof and fascia, renewal of deteriorated perimeter sealant, conservation of the stained-glass panels, and redecoration of external mullions and sills. All repairs will be undertaken on a like-for-like basis, replacing only defective elements. The proposals are intended to address deterioration, improve weatherproofing, and secure the long-term preservation of the stained glass and associated historic fabric, with no change to the building's appearance, character, or significance.
Pending

View Planning Timeline