The Old Post Office, Main Street, Grendon Underwood, Aylesbury, HP18 0SP

UPRN:766031524Detached House4 bedsBuilt 1900-1929

FreeholdCouncil Tax: Band GEPC: E (54)

Data freshness:Listing· freshPlanning· 5mo agoEPC· 6mo agoRisk· 5mo agoConnectivity· 1mo agoSchools· 4mo agoAmenities· 2mo agoArea· Census 2021

The Old Post Office, Main Street, Grendon Underwood, Aylesbury, HP18 0SP

HP Score

/ 100

Mixed

Verdict

3 days ago

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

Evidence

20 of 21 sources

Sale Estimate

£687,000

£653k - £722kHigh

Estimate

£687k

Range

£653k – £722k

Rent Estimate (pcm)

£2,550

£2k - £3k

Monthly

£2,550

Yield

4.53%

Verdict

Derived from HomePortfolio scores

The Old Post Office earns an INVESTIGATE rating with HP Score 64/100. Investment score 56/100 reflects moderate fundamentals. Crime intensity is very low. Walkability is limited (21/100). 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 leasesHM Land Registry Price PaidPlanIt / council planning portalsOverture Maps PlacesOfsted / DfE GIAS

HP Score

64/ 100

Mixed

Investment Score

56/ 100

Moderate

Crime Score

11/ 100

Low

Walkability

21/ 100

Low

Transit & Bike

Transit 8Bike 19

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 edge0/15
claims [AVM +1.7% (HIGH), sold-comps -3.2%, £/sqft -3.1%] → measured edge +0.00pp 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 12 Oct 2026
- valuation_snapshotsestimate for 766031524· as of 12 Oct 2026
- property_comparablessold-evidence family (implied value + £/sqft): 7 comps, dispersion 9.8%· as of 28 Oct 2026
Rental economics0/40
gross yield 4.5%; range width penalty ×0.81
- valuation_snapshotsrent estimate 2550/mo (range 2300-2800)· as of 12 Oct 2026· verify before relying on this
Stress margin0/30
stressed cash flow -1,103/mo, -43% 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), 33 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 & liquidity14.6/15
199 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

£506,000£776,000

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£675,000

At the asking price

Monthly rent£2,550/mo

Evidenced range £2,300-£2,800

Interest rate5.4%

Loan to value75%

Cash required: £227,550
Net cash flow: -£513/mo
Cash on cash: -2.7%
Score at this price: 15

After a 8% void allowance, 15% management and 10% maintenance. Lender coverage (rent ÷ interest): 1.12 - 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 766031524Valuation edge · as of 12 Oct 2026
property_comparablessold-evidence family (implied value + £/sqft): 7 comps, dispersion 9.8%Valuation edge · as of 28 Oct 2026
valuation_snapshotsrent estimate 2550/mo (range 2300-2800)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 2550/mo (range 2300-2800)
Seller motivation could not be scored
context, not scored: 0 price cut(s), 33 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£687,000

Rent Estimate (pcm)£2,550

Gross Yield4.53%

1y Growth-

3y Growth+0.8%

5y Growth+1.4%

10y Growth+2.5%

Last Sold Price£407,000 (2005-12-21)

View Market Details

Risk Overview

Flood RiskUnknown
SubsidenceSignificant
RadonLow
MiningUnknown
LandslideSignificant
Air QualityLow
NoiseModerate

View Full Risk Report

Planning Activity

Recent Apps

2HP18 0SP

Approval Rate

-12mo

Development

low

PL/26/08252/KA
Repollarding by approximately 4m to previous pollard points of the established pollard framework of Willow
Pending
PL/26/08253/KA
Crown reduction by 1.5m of Oak
Pending
PL/26/07400/TP
Crown reduction by 2m to a common oak to keep the tree safe and healthy in its environment.
Pending

View Planning Timeline

Ownership

Corporate Ownership72.3%
Overseas OwnershipNo
Lease Term Remaining-
CovenantsRestrictive
Lease TypeFreehold
Last Ownership Change2005-12-21
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£35,937

Population Density68 /km²

Owner Occupied80%

Age Distribution

0-15 18%16-64 63%65+ 19%

View Area Profile

Schools Nearby

Grendon Underwood School
0.1 mi
Inspected as Grendon Underwood Combined School (URN 110278) on 1 Feb 2024
Marsh Gibbon CofE Primary School
2.5 mi
Area grades2025
Inspected after Ofsted withdrew the single overall grade.
Twyford C of E School
3.7 mi
Good
Quainton Church of England School
4.0 mi
Good

2 of 14 nearby schools with published figures were oversubscribed in 2026 - demand, not a catchment.

View All Schools

Comparables

View All

Grendon Cottage Main Street
-
£373k
-
Lammas Close Main Street
-
£450k
-
Lower End Main Street
-
£155k
-
The Hollies Main Street
-
£435k
-

Boundary data not available for this property

No registered title polygon, building footprint, or street match for this property yet.

Why: No HMLR INSPIRE / OSM footprint / OS Open USRN match for this UPRN

Source: HM Land Registry INSPIRE / OpenStreetMap / OS Open USRN