UK Timber Price Index

The data

Questions this page answers

What the terms mean

Index

A number showing how a price has moved relative to a chosen starting point, rather than the price itself. An index of 120 means the price is 20% above its base period.

Base period

The period the index is measured against, set equal to 100. Forest Research uses September 2021 = 100 for this series. The Office for National Statistics uses 2015 = 100 for its producer price indices, so the two indices are not directly comparable in level, only in how they move.

Cash terms and real terms

Cash terms, also called nominal, is the price as actually paid at the time. Real terms adjusts for general inflation so prices from different years can be compared.

Overbark

Measured including the bark. Timber volume can be quoted overbark or underbark, and the two give different figures for the same tree, so the basis is always stated.

Standing sales

Timber sold as living trees, for the buyer to fell and extract. The price is therefore lower than sawn timber, which has been felled, transported, milled and dried.

Producer price index

A measure of the prices producers receive for goods leaving the factory gate, before wholesale and retail margins. The ONS series on this page measure sawn and planed wood at that stage.

Methodology

This section states exactly how the figures above are produced, where they come from, what they exclude, and what happens when one of them changes.

What is this index, and who calculates it?

iWood Timber Merchants does not calculate any index on this page. Every figure published here is taken directly from a United Kingdom official statistics publisher and presented unchanged. The only transformations applied are rounding to the publisher’s own stated precision and conversion of period labels to ISO dates.

What is deliberately not done to this data

• Nothing is rebased. Each series keeps the base period its publisher declared, even though that means the series are not directly comparable in level. Rebasing them to agree would produce numbers that disagree with the publishers’ own.
• Nothing is merged or averaged. No single index is computed across publishers, and no view offers one. Each publisher’s series stands on its own line, labelled with its publisher.
• Nothing is interpolated, smoothed or forward-filled. A period with no published value is shown as having no published value.
• Nothing is forecast. There is no trend line, no projection and no extrapolation beyond the last observation anywhere on this page. An index that predicts stops being a record.
• No iWood prices appear. These are market-wide official statistics.

How is the data checked before publication?

Every update passes ten validation gates before it can be published. Any single failure stops the build and writes nothing, leaving the previous release live. There is no override flag and no warning tier: a rule that proves wrong is changed deliberately, in a reviewed commit, rather than bypassed.

1. Every series carries a complete provenance block.
2. Observations are strictly ordered with no duplicate periods.
3. No gap is inconsistent with the series’ declared cadence.
4. The base period is present and equals 100.
5. Index and price series move consistently, which catches column misalignment.
6. Values fall inside a declared plausible envelope, and no single value is out of line with its neighbours.
7. No binary asset from a source file survives ingest.
8. The latest period is neither in the future nor implausibly stale.
9. Every numeric field carries a unit and a geography.
10. The set of series is unchanged unless a change has been declared.

What happens when a figure is corrected?

Published figures are never silently altered. A correction is published as a new release carrying a dated revision notice stating what changed, for which periods, and why. Where the correction comes from the upstream publisher it is recorded as an upstream revision and attributed to them, rather than absorbed as if it had always been so. Every correction ever made is listed under revision history.

When is this page updated?

Each source publishes on its own calendar and this page is rebuilt when one of them does. The next scheduled release is 19 August 2026, from Office for National Statistics.

• Coniferous Standing Sales Price Index (Forest Research), semi-annual , next November 2026
• Producer price index: output of wood, sawn and planed, home sales (Office for National Statistics), monthly , next 19 August 2026
• Producer price index: imports of wood, sawn and planed, from the EU (Office for National Statistics), monthly , next 19 August 2026
• Producer price index: imports of wood, sawn and planed, from outside the EU (Office for National Statistics), monthly , next 19 August 2026

Can I reuse this data?

Yes. The underlying statistics are published under the Open Government Licence v3.0, which permits commercial and non-commercial reuse with attribution. The CSV and JSON downloads are free and ungated, and both carry the attribution and licence wording in their headers so a file that travels separately from this page still carries its provenance.

Government logos, crests and the Royal Arms are excluded from that licence. The source spreadsheet embeds a publisher logo; it is never read during ingest and never appears here.

Revision history

Published figures are never silently altered. When a figure changes, the change is published here with its date, the periods it affects, and whether it came from the upstream publisher or from a correction made to this presentation.

Have any figures been revised?

How would I know if a figure I cited has changed?

Cite a release anchor rather than the page alone: each release below has its own permanent address, and the release you cited records the figures it published. Any subsequent correction to those figures appears in this section with the periods it affected, so the two can be compared directly.

Release history

Each release is a dated publication event with a permanent address on this page. A release records what it added and the figures it led with; it is written once and not rewritten when later figures arrive.