How Offrly Works

An honest, outcome-oriented view of what Offrly produces, where it's reliable, what it does not factor in, and how we measure accuracy in public.

The short version

Offrly is a free UK property analyst with two tools — AI-graded property search and instant sale or rental valuation. Both run in about 30 seconds, free, with no signup. The estimate is indicative market guidance — not a regulated valuation, not financial / tax / legal advice.

Below: what we produce, what's in the estimate, what's not, where it's reliable, where it isn't, and how we publish accuracy.

What you get from a valuation

• A point estimate of sale price (or monthly rent if you switch to the rent channel).
• A price range that reflects the spread of comparable evidence.
• A confidence score that drops when there's thin comparable evidence in the area.
• The live comparables the model used, so you can sanity-check the answer yourself.
• A per-property-type signal — flats are matched against flats, leasehold against leasehold, bungalows against bungalows.

What you don't get: a regulated valuation, a building-condition survey, a financial-advice or tax answer.

What you get from a property search

• A natural-language brief — describe what you want in plain English.
• Live UK listings pulled at query time (sale or rent).
• Each listing graded 0–100 for how well it matches your brief.
• Reasoning tags that explain each score so you can see why a listing scored.
• An iteration loop: tell the AI what you want more or less of and the shortlist re-ranks.

What you don't get: a viewing booking, a mortgage decision, an offer process. Offrly is intelligence; the transaction layer is whoever is selling or letting the home.

What's IN the estimate

• Comparable evidence. Live UK listings nearby, pulled at query time. Nothing cached from last month.
• Photo signals. The AI reads each comparable's listing photos for garden quality, internal condition, layout, finish — the same signals a seasoned property analyst would weigh during a viewing.
• Hyperlocal pricing. Prices are resolved closer to the street than to the broad postcode area. Two homes on the same road, one immaculate and one tired, get materially different numbers.
• Tenure differentiation. Leasehold, share-of-freehold and freehold homes are matched against tenure-equivalent comparables. We don't borrow freehold prices to value a leasehold flat.
• Property-type differentiation. Bungalows are valued against bungalows; detached homes against detached. Each segment trades on its own demand profile.

What's NOT in the estimate (and matters separately)

These items genuinely affect what a UK home is worth on the open market — but they don't reliably show up in listing photos or comparable sale prices, so the AI does not see them. Treat them as buyer-side due diligence items, not failures of the estimate:

• Lease length (years remaining on the lease). Material below 80 years; can impair mortgage availability below 70. The number is in the seller's pack — your solicitor will pull it.
• Ground rent terms, especially escalation clauses (10-year doubling, RPI-linked, fixed-step).
• Service charge and sinking-fund contributions, plus any pending major-works estimates.
• Cladding / EWS1 status in higher-risk buildings — affects mortgage availability and price.
• Specific structural / planning issues — subsidence, restrictive covenants, planning enforcement, party-wall disputes, drainage / off-grid utility concerns.
• Listed-building obligations and conservation-area planning constraints that affect what you can do with the property.
• Boundary disputes, easements, and any access-right restrictions.

The right tools for those: the seller's pack, a RICS-qualified surveyor, and your solicitor. Use Offrly's estimate as a fast, free first-pass market answer; use those professionals to close the loop.

Where Offrly is most reliable

• Standard freehold homes (detached, semi-detached, terraced) in well-populated areas with active recent comparable activity.
• Standard leasehold flats where the lease is a normal term (typically 99/125/250 years, low ground rent, ordinary service charge) — though we still recommend verifying lease finance separately.
• Postcodes with enough live comparables to populate the model with real signal.
• Photo-rich listings — when comparables include lots of photos, the AI has more to work with.

Where Offrly is less reliable

• Unusual stock. Listed buildings, converted commercial, mixed-use, exceptionally-large estates.
• Very short leases (typically under 70–80 years remaining). The market prices these on lease-extension premium calculations the model does not have access to.
• Brand-new schemes with no prior resale history. The model leans on similar-spec resales nearby, which is a less direct signal.
• Very rural / unique properties with few comparable listings within scraping range.
• Photo-poor listings — where there's little to read, the AI's added value over a postcode-average tool shrinks.

When confidence is low, the model says so via the confidence score and the wider price range. Use the figure loosely in that case.

Coverage

Offrly covers the United Kingdom only — England, Scotland, Wales and Northern Ireland — subject to live comparable listings being available in the area. We do not cover Ireland, the Channel Islands, the Isle of Man or any non-UK market.

For sold-price intelligence on location pages, England and Wales coverage comes from HM Land Registry Price Paid Data under Open Government Licence v3.0. Scotland and Northern Ireland have separate registers; we use city-level summaries for those.

How we measure accuracy in public

We publish an honest, transparent accuracy report. Every Offrly sale valuation is logged with its postcode and predicted price. When HM Land Registry publishes its monthly sold-price data, an admin reviews candidate matches and confirms which Offrly predictions ended up being a real later sale. Only confirmed pairs feed the published metrics. The figures there — hit-rate within ±10%, MdAPE, MAE, per-property-type breakdowns — are the only accuracy claim Offrly makes.

This is a prediction-vs-outcome report, not a synthetic back-test. Each figure traces back to a real Offrly prediction made strictly before the eventual sold date. Predictions never see future sold prices.

Rentals are not in the accuracy report — there is no public sold-rent register equivalent for rentals to pair predictions against.

What Offrly does not do

• It is not a regulated valuation. For mortgage, insurance, probate, tax-binding or court purposes, you need a RICS-qualified surveyor.
• It is not financial, tax or legal advice. For those questions, see the relevant qualified professional.
• It is not a long-term price forecast. Offrly produces a current-market estimate based on current comparable evidence; market conditions change.
• It is not a substitute for a building survey — Offrly cannot see structural defects, damp, subsidence, roof condition or anything else a surveyor would catch in person.
• It is not a substitute for due diligence — read the seller's pack, ask your solicitor about lease finance and search results, and view the property.

Feedback

If you think an Offrly estimate is materially off, let us know via the contact form. Off-by-a-lot examples — with the address or postcode and the headline reason — are the most useful kind of feedback.