A number you can trust.
Trained on tens of millions of data points across hundreds of thousands of UK properties. Offrly's AI reads every listing , including photos , so your valuation reflects what the home actually is.
Paste the full Rightmove listing URL. We'll pull the property details and have our AI assess condition from the listing photos.
How to model an improvement's value uplift
Wondering what an extra bedroom, a loft conversion, an extension or a refurbishment would add to your home? Run the valuation above, then use the Scenario Explorer on the result card.
- Run a free valuation. Postcode + a few details. About 30 seconds. No mandatory signup.
- Open the Scenario Explorer. On the result card — sliders for bedrooms, bathrooms, floor area, garden size and interior condition.
- Move the slider for your improvement. Loft conversion or extension that adds a bedroom: bedroom slider +1 and floor-area slider +20–30 m². Refurbishment: condition slider up one or two tiers. Extra bathroom: bathroom slider +1.
- Click Recalculate. Offrly re-prices the same property against the same live UK comparable set. The £ delta is your modelled uplift for that change on that specific home.
- Compare scenarios. Reset to original between runs. Pair the modelled uplift against a builder or quantity-surveyor cost estimate before committing.
Frequently asked questions
Is Offrly's property valuation free?
Yes. No mandatory signup, no email, no card. Offrly is a free public tool — the valuation, comparables, sold-history table and Scenario Explorer are all free end to end.
How does the Scenario Explorer work?
Once your valuation lands, the result card shows sliders for bedrooms, bathrooms, floor area, garden size and interior condition. Each Recalculate re-prices the same property against the same live UK comparable set with the perturbed inputs — the delta is the modelled uplift for that change on that specific home. Sliders are clamped within ±2 bedrooms, ±2 bathrooms, ±25% floor area, ±2 garden tiers and ±2 condition tiers from the original valuation.
Can I see how much an extra bedroom or extension would add to my house?
Yes — that's exactly what the Scenario Explorer is for. Run a free valuation (about 30 seconds), then drag the bedroom slider up by one for an extra bedroom, or the floor-area slider up by 20–30 m² to model a loft conversion or extension. Click Recalculate; the modelled new price appears with the £ delta against your original valuation.
How accurate is the modelled Scenario Explorer uplift?
The Scenario Explorer uses the same regression-based pricing on photo-aware, micro-neighbourhood-aware comparables that produced the original valuation — just with the perturbed inputs. It is an indicative market estimate of how the change would price against today's live UK comparable set, not a guarantee. Build cost, condition of the rest of the house and post-completion buyer-panel reactions are not modelled.
What inputs does an Offrly valuation need?
A UK postcode plus a few property details — bedrooms, bathrooms, property type, tenure, garden size and interior condition. Optionally a Rightmove URL, in which case Offrly extracts most of the details and reads the property's photos for garden and condition. About 30 seconds end to end.
Can a free online valuation replace a RICS survey?
No. A RICS survey is a regulated, physical inspection of a specific property by a qualified surveyor. Offrly produces an indicative market estimate, not a regulated valuation. For mortgage, insurance, probate, tax or legal purposes, use a RICS-qualified surveyor.
What does the Scenario Explorer NOT model?
It models how today's live UK comparables price your home with the perturbed inputs. It does not model build cost, planning risk, the timing impact of a renovation, the condition of the rest of the house when you add an extension, or post-completion buyer-panel reactions to specific finishes. Pair the modelled uplift with a builder or quantity-surveyor cost estimate before committing.
How often is the comparable data refreshed?
Every valuation pulls live UK comparable listings at the moment you ask — nothing is cached from last week. The Scenario Explorer reuses the comparable set from your most recent valuation so the modelled uplifts are calibrated to the same data.