To my understanding restoration is about returning something to, or at least close to, its former state. In a sense that is what I want to do to my house. However, I guess I do want to go beyond this in the sense that I want to restore what is there, or there is evidence of, but when things are not there I will create my intepretation of the style and feel (based on evidence from the period but not from my house). I will get it wrong, I may over "Victorianise" the decor, but I try not remove the original materials that exist.
I have noticed that Historic Scotland, and other bodies have a very strict view on restoration. In some cases old buildings are allowed to crumble and fall into ruins. They may not be "restored" to their former glory. While I understand the need not to create a pastiche, I often feel that potentially savable buildings could be more valuable for the community if they are restored with some compromises. In many cases buildings are A-listed and then left to crumble and not even preserved in their current state since the restrictions mean they are not going to be useful buildings and so no-one will invest in these.
I think we could be more lenient, but not stupid, about the how many historic buildings can be restored. However, we could also be more strict about our vast legacy of Victorian houses which we are permitted to destroy without seeking any permission. Doors are now plastic, stone is painted, lime only means a green fruit, portland cement destroys natural porous stone, mullions are removed, thin framed sash windows are replaced with riduculous fat framed upvc alternatives. I think the balance is wrong and maybe too much attention is paid to a few buildings and too little attention is given to our vast collection of period houses.