35 Grass Warren, Tewin, Welwyn, AL6 0JL

UPRN:100080757995Semi-Detached House3 bedsBuilt 1950-1966

FreeholdCouncil Tax: Band DEPC: D (63)

Data freshness:Listing· freshPlanning· 4mo agoOwnership· freshEPC· 1mo agoRisk· 5mo agoCrime· freshConnectivity· 1mo agoSchools· 1mo agoAmenities· 2mo agoArea· Census 2021Council Tax· 1mo ago

HP Score

/ 100

Mixed

Verdict

today

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

Evidence

17 of 21 sources

Sale Estimate

£677,000

£609k - £745kMedium

Estimate

£677k

Range

£609k – £745k

Rent Estimate (pcm)

£2,450

£2k - £3k

Monthly

£2,450

Yield

5.11%

Verdict

Derived from HomePortfolio scores

35 Grass Warren earns an INVESTIGATE rating with HP Score 65/100. Investment score 50/100 reflects moderate fundamentals. Crime intensity is low. Walkability is limited (38/100). 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)Defra 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

65/ 100

Mixed

Investment Score

50/ 100

Moderate

Crime Score

28/ 100

Moderate

Walkability

38/ 100

Mixed

Transit & Bike

Transit 5Bike 23

Walk Score, out of 100

Opportunity

Why this could be an opportunity

Low confidence0 independent sourcesLead to verifyListing checked 11 Nov 2026

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

Check before relying on this score: the estimate sits 15% above the ask. It ranks after every home whose inputs are verified.

Valuation edge0/15
claims [AVM +15.1% (MEDIUM)] → 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 (MEDIUM confidence) · snapshot 10 Nov 2026
- valuation_snapshotsestimate for 100080757995· as of 10 Nov 2026
Rental economics0.7/40
gross yield 5.1%; range width penalty ×0.79; the estimate this rent rides on sits 15% above the ask - check the rent describes the advertised home
- valuation_snapshotsrent estimate 2450/mo (range 2200-2700)· as of 10 Nov 2026· verify before relying on this
- valuation_snapshotssale estimate 15% above the ask on the same snapshot - verify the rent describes this home· as of 10 Nov 2026· verify before relying on this
Stress margin0/30
stressed cash flow -755/mo, -31% 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 11 Nov 2026
Seller motivationNot scored
context, not scored: 0 price cut(s), 70 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 11 Nov 2026
Risk & liquidity12.8/15
98 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

£431,000£661,000

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£575,000

At the asking price

Monthly rent£2,450/mo

Evidenced range £2,200-£2,700

Interest rate5.4%

Loan to value75%

Cash required: £192,550
Net cash flow: -£244/mo
Cash on cash: -1.5%
Score at this price: 14

After a 8% void allowance, 15% management and 10% maintenance. Lender coverage (rent ÷ interest): 1.26 - clears 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 100080757995Valuation edge · as of 10 Nov 2026
valuation_snapshotsrent estimate 2450/mo (range 2200-2700)Rental economics · as of 10 Nov 2026 · verify before relying on this
valuation_snapshotssale estimate 15% above the ask on the same snapshot - verify the rent describes this homeRental economics · as of 10 Nov 2026 · verify before relying on this
underwriting_assumptionscosts not disclosed by the advertStress margin · as of 11 Nov 2026
portal_listingsprice_changes + first_published_dateSeller motivation · as of 11 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 2450/mo (range 2200-2700)
Rental economics needs verification before you rely on it
sale estimate 15% above the ask on the same snapshot - verify the rent describes this home

Plan

Before you offer

1. Get two written rental appraisals from local lettings agents.
The market estimate this rent rides on sits far above the asking price, so the rent may describe a different home.
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£677,000

Rent Estimate (pcm)£2,450

Gross Yield5.11%

1y Growth-

3y Growth-1.8%

5y Growth+0.4%

10y Growth+1.4%

Last Sold Price-

View Market Details

Risk Overview

Flood RiskUnknown
SubsidenceModerate
RadonLow
MiningModerate
LandslideLow
Air QualityLow
NoiseLow

View Full Risk Report

Planning Activity

Recent Apps

0AL6 0JL

Approval Rate

-12mo

Development

low

3/26/1453/PIP
Permission in principle for erection of 1 x detached dwelling
Pending
3/26/1378/TDCMIN
Technical details consent for construction of 3 x detached dwellings with associated works and creation of new access from Archers Green Lane following permission in principle 3/25/1999/PIP
Pending
3/26/1245/HH
Construction of orangery
Pending

View Planning Timeline

Ownership

Corporate Ownership71.1%
Overseas OwnershipNo
Lease Term Remaining-
CovenantsRestrictive
Lease TypeFreehold
Last Ownership Change-
SourceLand Registry

View Ownership Details

Connectivity

Broadband (Standard)

5 Mbps

Mobile 4G/5G Coverage

EEThreeO2Vodafone

EV Charger

PTAL Rating

View Connectivity Map

Area Profile

Median EarningsLocal authority£44,154

Population Density-

Owner Occupied76%

Age Distribution

0-15 17%16-64 60%65+ 23%

View Area Profile

Schools Nearby

Tewin Cowper Church of England Voluntary Aided Primary School
0.2 mi
Area grades2024
Inspected after Ofsted withdrew the single overall grade.
Springmead Primary School
0.8 mi
Good
The Holy Family Catholic Primary School
1.0 mi
Inspected as The Holy Family Catholic Primary School (URN 117481) on 15 Oct 2024
Waterside Academy
1.0 mi
Report card2026
Ofsted no longer awards a single overall grade.

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

View All Schools

Comparables

View All

30 Grass Warren
-
£525k
-
31 Grass Warren
-
£595k
-
29 Grass Warren
-
£708k
-
37 Grass Warren
-
£355k
-

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