Accuracy

How accurate is it?

The estimate is a starting range, not a survey or a matched sale price. Address-level LPS records are not currently loaded. The current result uses official Derry City and Strabane market data, a modelled property-type baseline and the details you supply, so it is labelled low confidence.

What can affect the estimate

• Condition, extensions, gardens, parking, views, and unusual layouts.
• Recent upgrades that are not visible in the official valuation data.
• Thin data for rare property types or new builds.
• Buyer demand changing faster than quarterly HPI data.

The current engine applies a transparent 1.064 market calibration after its HPI, local-area, and property-detail calculations. This produces estimates 5% below the previous engine following local homeowner feedback, while retaining a modest current-market adjustment above the underlying model. The calibration remains subject to review as more verified comparisons are collected.

Why we show a range

Every estimate includes a point figure and a range. Low confidence means the property has not been matched to an address-level record. It does not mean a measured chance of achieving the price. Check floor space, condition and comparable homes with a local agent before setting an asking price.

Disclaimer

This is an estimate, not a formal RICS valuation. Do not use it for legal, mortgage, tax, or investment decisions.