Wood Calorific Value

When choosing wood for burning there are three factors which have an effect on the calorific value (CV) or the amount of available heat per unit of fuel:

  1. Species Choice
  2. Wood Density
  3. Moisture Content

Species Choice

The general differences are that hardwoods (deciduous, broad-leaved tree species) tend to be denser, and softwoods (evergreen, coniferous species) tend to contain more resins. There is little variation of CV between species when tested at the same moisture content.


A scheme to help protect against threats to tree health from imported firewood came into force on 1 January 2017.

The Statutory Notification Scheme for importing solid wood fuel (firewood) requires importers bringing certain types of firewood into England and Scotland from outside the UK to provide prior notice of its arrival to the Forestry Commission. At least three days’ prior notification is required if the shipment is coming by sea, road or rail, and four hours’ notice if it is arriving by air.

The regulation covers solid wood fuel (firewood) in the form of logs, billets, twigs, faggots and similar forms. All relevant consignments, irrespective of size or weight, must be notified.

The scheme enables the Forestry Commission to gather information about the firewood importing trade, and to carry out risk-based and random inspections of a selection of imports, mainly at importers’ premises. This will help to ensure that the firewood or its associated wooden packaging, such as pallets and crates, meets British plant health landing requirements.

Please make sure your supplier complies with this regulation. We do not want even more diseases coming into the country, threatening our trees and wildlife!

 All wood fuel supplied by Box End Firewood is sourced locally, legally and from sustainable woodlands.