Property price reporting frequently cites contradictory figures in the same week, and the contradictions follow from what each index measures.
Asking prices
What sellers list properties at.
Which is the earliest available signal and reflects hope rather than transaction.
The gap between asking and achieved prices widens in falling markets.
Mortgage approval data
Prices from lenders at the point of approval.
Which is earlier than completion and covers only mortgaged purchases.
Cash purchases are excluded, and these are a substantial share in some markets.
Land registry data
Completed transactions with actual prices.
Which is the most complete and the most delayed, lagging by months.
It is the definitive record and arrives after the period it describes.
Mix adjustment
Average prices change when the composition of what sells changes.
Which means an average can rise without any individual property gaining value.
Mix-adjusted indices correct for this and are the more meaningful measure.
Repeat sales methods
Tracking the same properties over time.
Which removes composition effects entirely.
It excludes new build and properties that have not sold twice.
Regional variation
National figures aggregate markets moving in different directions.
Which makes them nearly useless for anyone's actual decision.
Local data at postcode or district level is what matters and is published.
Transaction volumes
Frequently more informative about market conditions than prices.
Which fall sharply before prices adjust, since sellers withdraw rather than reduce.
Volume data is published alongside price indices and is rarely reported.
Reading coverage
Check which index, what it measures, what period it covers and whether it is mix-adjusted.
Most apparent contradictions dissolve once those questions are answered.
New build premiums
New properties frequently sell above comparable existing stock.
Which affects indices that include them.
The premium tends to erode on resale, which surprises buyers.
Rental data
Measured separately and driven by different factors from sale prices.
Which can move in opposite directions to prices.
Yields — rent relative to price — indicate how the two relate.
Affordability measures
Price relative to income is the measure that matters for access.
Which is published and is more informative than price levels alone.
Deposit requirements are a separate barrier that price-to-income ratios do not capture.
Transaction costs
Taxes, fees and moving costs are substantial and are excluded from price indices.
Which matters for anyone actually transacting.
Changes to transaction taxes produce visible distortions in monthly transaction data.
Interest rate effects
Borrowing costs affect what buyers can pay far more than headline prices suggest.
Which is why price and affordability can diverge sharply.
Seasonality
Housing markets have pronounced seasonal patterns in both prices and volumes.
Which is why indices are published in both adjusted and unadjusted form.
Comparing an unadjusted monthly figure to the previous month conflates seasonality with trend.
Sample composition
Lender-based indices cover that lender's business rather than the whole market.
Which introduces composition effects if the lender's customer profile differs from average.
Methodology notes state the coverage explicitly.
Revisions
Transaction-based indices revise as more completions are registered.
Which means recent months are provisional.
Revisions have occasionally reversed the direction of a reported monthly change.
Forecasts
Published by lenders, agents and research firms with obvious commercial interests.
Which does not make them wrong and is relevant context.
Their historical accuracy is checkable and is generally unimpressive.
What to actually use
Local transaction data for your area, volumes alongside prices, and affordability relative to local incomes.
Why coverage is confusing
Several indices publish in the same month measuring different things over different periods with different methods.
Which guarantees apparent contradiction.
Reporting rarely names which index it is citing, let alone what that index measures.
The one figure worth following
Completed transaction prices for your local area, alongside transaction volumes.
Which is published by land registration bodies and is the definitive record, albeit delayed.
A closing observation
Property is the largest financial commitment most people make and is reported using indices that disagree with each other by construction.
Local completed transaction data answers the question anyone actually has, arrives late, and is free.
Everything published faster than that is an estimate of it.
Leasehold and tenure
Tenure differences affect value and are inconsistently captured in indices.
Which matters particularly for flats where lease length materially affects price.
Short leases can reduce value substantially and complicate mortgage availability.
Condition and improvement
Indices do not adjust for property condition or for improvements made.
Which means a repeat sale reflects both market movement and any work done.
This is a known limitation of repeat sales methods and is documented in methodology notes.
A final note
Housing coverage manages to be simultaneously constant and uninformative, largely because indices measuring different things over different periods are reported interchangeably.
Local completed transaction data, alongside volumes, answers what people actually want to know.
It arrives months late, and it is the only figure in the whole discussion that records what somebody actually paid.