farmhouse renovation options

I am in the process or designing an extension to my parents farmhouse.

The house was built in 1912 with the only significant alteration being the addition of a front corridor approximately 10 years ago. During this process rising damp was treated and the house was insulated internally. This will need to be revisited but I want to tackle the big issues first. The house currently has a stove in the living room and in the kitchen.

I need to add attic and ceiling insulation to the existing house. The existing windows are single glazed timber sash windows. Is triple glazed worth the cost or would I go with high spec double glazed. Does anyone know a good custom joiner?

I think solar panels will be fine for water heating and could be supplemented by a boiler. There are only ever 3-4 people there so there is not extensive water usage.
I would prefer not to need an oil boiler but is it the most realistic option. What would I need to incorporate to remove dependence on the grid?

If anyone can point me in the right direction, it'll be much appreciated.

Calahonda52

This is a little disjointed and its not clear what direction you need pointing in.

Lets start with some basics:
Please describe, exactly, the wall and roof construction of the original 1912 house as it is now.
So starting on the inside
skim on Xmm insulated plaster board....

How exactly was rising damp treated?

Whats the reasoned, ecological and economic, argument for this statement?
I think solar panels will be fine for water heating and could be supplemented by a boiler.