Historically oak was the timber of choice for construction until the second half of the 18th century, when it became very expensive.
Consequently the pine forests of the Baltic were sourced for an alternative supply and this is the very durable timber found in most historic buildings that date from 1750-1900.
Modern softwood has a high degree of sapwood, which lacks natural durability and when damp will be attacked by many forms of pathogens from beetle to dry rot.
When repairing historic buildings it is therefore important to select timbers that contain the minimum amount of sapwood.
There has been recent development of acetylated softwood whereby the cellulose is modified by binding it with the major component of vinegar. This greatly enhances the durability of the sapwood and also makes the timber more dimensionally stable.