Summary
The UK House Price Index helps buyers adjust older comparable sales to current market conditions. It should be used carefully because it is based on completed sales and can lag the market.
Definition
The UK House Price Index measures changes in residential property values using completed transaction data from across the UK. It includes cash and mortgage transactions and publishes data at national, regional and local levels depending on the geography. A buyer can use it to time adjust a comparable by scaling the old sale price from the sale month to the valuation month. For example, if the relevant local index rose by 2 percent between the comparable sale month and today, multiply the comparable price by 1.02 before applying other adjustments. It is a helpful anchor, but it should not replace local comparable evidence, especially in thin or fast moving markets.