"Preservation" - works aimed at stabilising the current condition of a building without making fundamental improvement changes to same.
"Restoration" - works aimed at taking a building back to a previously known condition generally at a recognised period in time. Could imply removal or reversal of later alterations and additions.
Agree / disagree ?
This makes some sense ken but I should ask if when preserving a building and it has some bad rot in places, can you repair, replace or otherwise restore a single or multiple pieces while still preserving the whole?
