i · Will not
Widen the property type to reach a number.
A flat is compared to flats. If the cohort is thin, the methodology widens geography before it ever widens type — and discloses the stage it stopped at.
Methodology
Every claim has a name and a source.
The value is not in any single dataset — anyone can look up a sold price. It is in the intersections: what the registered sale record can say once it is matched to a property's structural attributes, corrected by the house-price index, and joined to its official geography. An estimate that leans on one source produces a guess. A methodology that integrates fourteen produces intelligence.
Same market, two methods
Why an algorithm's guess isn't evidence.
How algorithms guess
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Lagging data
Most portal estimates rebase against an index that updates monthly or quarterly — a model of last cycle's market, applied to this week's question.
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Anchored to the asking price
Many valuation models are trained on, or nudged toward, what the property is listed at — which is the seller's opening position, not evidence of what it's worth.
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Blind to non-arm's-length sales
Family transfers, corporate-to-corporate sales and repossessions get averaged in alongside genuine market transactions, quietly skewing the number.
The SettleIQ standard
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HM Land Registry, directly
Every figure traces to a registered, completed transaction — the price that was actually paid, not the price that was asked.
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Strict £/sq ft standardisation
Floor area is cross-checked against the EPC register and verified three ways before it's allowed to carry a number — not estimated from a floorplan thumbnail.
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Distress & renovation signals flagged
Sales carrying the signature of a recent full renovation, a structural defect, or a probate sale are flagged and excluded from the standard cohort — not blended in as ordinary market evidence.
From raw registers to a number
The filtration waterfall.
Four stages, always in this order. Nothing reaches the tactical bracket without surviving all four.
- 01
Data ingestion
HM Land Registry Price Paid Data and thirteen other public registers are pulled in raw — nothing pre-filtered, nothing pre-modelled.
- 02
Anomaly filtration
Family transfers, gifted transactions, and sales carrying the signature of a recent full renovation, a structural defect, or a probate sale are flagged and stripped out before anything is averaged.
- 03
Square footage standardisation
Every surviving sale's floor area is cross-referenced against the EPC register, so price-per-square-foot is compared on a verified basis, not a listing agent's estimate.
- 04
The tactical bracket
The cohort's standardised £/sq ft sets the Glass Box Anchor. Four leverage signals then position the Open, Aim and Walk prices around it.
The rule that does the work
The Identity Lock
Identical is not a vague word here. The methodology locks five dimensions before a single transaction is allowed into your cohort. A two-bed leasehold flat is matched only against other two-bed leasehold flats in the same age and floor band.
- Property typeFlat, terrace, semi, detached. Never blended to reach a larger sample.
- TenureFreehold and leasehold are different legal assets and are never compared to each other.
- Age bandA pre-1929 conversion and a 2015 block have different cost bases and different buyers.
- Floor bandBedroom count and floor-area band together, so a 480 sq ft two-bed is not read against a 900 sq ft one.
- Plot sizeFor houses only. Two identical semis on different plots are not the same asset.
When evidence is thin
The geography cascade.
The search starts at the tightest geography available — the subject's own postcode sector — and widens only if it must. Each folio discloses the stage it stopped at, because a cohort assembled from three miles away is a different quality of evidence from one assembled from three streets away, and you are entitled to know which you were given.
- Stage 1Postcode sector
- Stage 2Local authority district
- Stage 3Adjacent districts
- Stage 4Borough / wider authority
- ThresholdBelow 8 transactions after Stage 4, no bracket is produced.
The evidence base
Fourteen datasets, in the order the methodology consumes them.
Identity first, then price, then time, then geography, then liability, then amenity. The numbering below is the processing order, not a ranking.
- §01 VOACouncil Tax Valuation List Valuation Office Agency
The property spine. Establishes that the address exists as a distinct dwelling and fixes its band.
Verify - §02 EPCEnergy Performance of Buildings Register MHCLG
Property attributes and the floor area used by the anchor — cross-checked three ways before it is allowed to carry a number.
Verify - §03 HMLRPrice Paid Data HM Land Registry · 1995 — present
Every registered transaction behind the cohort. Named, dated, and verifiable at landregistry.data.gov.uk.
Verify - §04 UKHPIUK House Price Index ONS / HM Land Registry
Time-adjusts historical sales to today at local-authority-month resolution. A 2023 sale is not a 2026 comparable until it is corrected.
Verify - §05 NSPLNational Statistics Postcode Lookup ONS
Official geography. Defines the postcode sector the identity lock searches first, and the cascade it widens into only if it must.
Verify - §06 NaFRANational Flood Risk Assessment Environment Agency · NaFRA 2025
Flood exposure from rivers, sea and surface water. Feeds the insurance-risk severity scale and the conveyancing question list.
Verify - §07 RadonRadon Potential Classification BGS / UKHSA
Whether the address sits in an affected area and at what class — a remediation cost that is never in the listing.
Verify - §08 PlanningPlanning Data (conservation areas, Article 4) MHCLG
Whether permitted-development rights have been withdrawn. Determines what a buyer can and cannot change after completion.
Verify - §09 NHLENational Heritage List for England Historic England
Listed status on the building or its immediate context, with the consent regime that follows from it.
Verify - §10 IMDIndices of Multiple Deprivation MHCLG · 2019 + 2025
Living environment, income, crime and barriers domains at LSOA level — read as directional context, never as a verdict on a street.
Verify - §11 GIASGet Information About Schools + Ofsted DfE / Ofsted
Catchment-relevant school records and current inspection grades, distance-ranked from the address.
Verify - §12 NaPTANNational Public Transport Access Nodes DfT
Every stop, station and interchange within walking range — the transport claim in the listing, checked.
Verify - §13 OfcomConnected Nations Ofcom
Verified fixed-line and mobile availability at the premises. Advertised speed is a marketing figure; this is the record.
Verify - §14 OSMOpenStreetMap OpenStreetMap contributors
Amenity proximity and the physical context around the plot — what is actually next door.
Verify
The constraints
Three things this methodology will not do.
Each of these makes the product harder to build and occasionally makes it return nothing at all. Each is also the reason a folio can be argued from in a room with a professional negotiator.
ii · Will not
Rest an anchor on an unverified floor area.
The listing’s square footage is a claim. A 5% measurement error on a £647/sq ft flat is roughly £24,000 — several times the width of the offer bracket.
iii · Will not
Name a number it cannot defend.
Below ten registered transactions after the full cascade, the methodology returns a sparse-cohort outcome and a recommendation to pause. Silence is sometimes the honest output.