The answer is YES. Travelers, visitors want to see those buildings and take pictures of those buildings. That perhaps is the main reason they visited a place. They are not going to visit and take pictures of concrete or glass monstrosities.
I'm neither an architect nor a historian, but I'd rather see a sensitively restored heritage building than watch it crumble and eventually have to be demolished. So long as repurposing it doesn't destroy its essence. However I've heard restoration can cost more than rebuilding?
They are not only sustainable , but the only way to re-use them in a contemporary way. Heritage buildings should be considered something that we can continue to be able to relate in our everyday life. Musealized architecture is dead architecture.
In Italy there are many abandoned small towns and villages, particularly in the South. Sometimes we reuse old houses as units of a bigger “hotel of charme”, respectful of the place. We restore old houses and gather together as rooms of one ***** hotel or small apartments tourists and visitors can rent. Sometimes is the only way we have to prevent depopulation. I think a better solution could be renting them to young professionals attracted by slow life. In such case restoring would need public financing.
There are some wonderful examples of repurposing in Australia, even though it is a place that has a relatively brief history of a "European" type of built environment.
One of my favourites is an old flour mill in the New South Wales town of Junee. It's been converted into a Licorice factory. They even include educational tours of the flour mill to interpret its previous economic use.
There is so much research going on in the areas of energy efficiency of traditional buildings and adaptation of traditional buildings. Claiming that traditional (mass masonry for example) structures are 'old and cold' and can not be efficient is no longer acceptable. I personally think adaptive re-use of heritage buildings is already culturally, and environmentally sustainable and the economic will follow as reserach continues and new materials and methods come to light.
In tropical climates adaptive reuse of heritage buildings may incur costs that are much higher than associated benefits. Particularly so for commercial reuse. Especially when in most cases, the ventilation and insulation needs to be customized/upgrade or a total overhaul to prevent/mitigate 'sick building syndrome'. Thereby resulting in a building that is less energy efficient than a custom-built building for a similar use and of the same size.
Article Sick-building syndrome in a tropical city
Article Energy savings versus costs of implementation for demand sid...