If that is the case, don’t replace the door. You can buy sticky type insulation foam to better insulate the door. But a proper wooden door, you keep.
In terms of the placo and the pipes, well you will never know. It is a gamble but not an expensive one. Even if there are pipes I sure you will have enough space to deal with it. You might need a plumber, but it is cheaper than a new door.
If you find the space then you can put up a curtain to block the drafts.
You can get a beautiful new timber door made to measure but as @anon44939055 says it will be expensive. Somewhere in the region of 800 - 2000 euros depending on the level of detail you require, plus a few hours to fit it and make good.
Draughts cost money in wasted heating, if you don’t have the budget to get it replaced then I would try to bodge some draught exclusion around the frame. It’s only a temporary fix though imo.
@James - have you still got a photo anywhere of the St Genes door - now that was a door! am feeling a ‘Great French doors’ thread coming on…!
Can’t find one 
Find a carpenter who can replace the door frame to fit your original door. I have had bespoke doors and windows made for my house and they really were not that much more expensive than buying doors off the shelf and having them fitted. The only way to know what is hiding behind the placo is to have a look.
For many reasons I will be rebuilding my timber shutters with new timber this summer on the existing brackets. Whilst I prefer oiled timber we will be painting them.
The brackets will be sandblasted and hammerite’d or primered.
I’d like to do a ‘proper job’ and not spend every summer re-painting. We are in Lot-et-Garonne so we get both wet and scorching sun.
So my questions are;
a) should I be using hardwoods or can I use a soft wood?
b) how many coats of primer, undercoat, topcoats? (I’d prefer to do overkill the first time to avoid having to sand and re-do the painting frequently)
c) what brands of paint are recommended or to be avoided based on your experiences?
Thanks in advance,
Ray
Just a query, any plasters in France ? Or is it common practice too Placo, Placo, Placo every available surface & hide the problem???
Hardwood is nice, & if treated correctly from the beginning will last much much longer, although softwood if exterior graded, will be just as good if treated in the same manner.
We must try & define Painting as obviously we imagine if it’s a soft wood: Knot, Prime and Fill, Minimum 2 udercoats, then top coat too finish.
As previously mentioned you can complete this job all in Oil based Paints but the Final too oat is the tricky one !! It will have too be Micro Pourous paint too allow the timber too breath, i.e. Allow moisture in and out naturally. The biggest problem I see here is that people do spend a lot of time preparing their existing shutters rite back too bare timber all nice and smooth and apply numourous coats of the top coat, no primer, no undercoat, this completely seals the timber and looks brilliant for one summer.
Your seriously would be better off if available here too use Sadolin Oil based they do a huge range of colours I’m sure admin will tell you it can be shipped out if not in any shelfs here but it’s brilliant fantastic product along with Sikkens slightly more expensive again. But excellent products that I have personally used for almost 40 years.
Hope this helps but go for the Sadolin, & when the sun bleaches the colour out of them which it will in time at least you won’t have a massive amount of preparation too recoat them generally just a dust off wipe down and apply another coat, these products penetrate the timber bit seal it which allows the timber too breath naturally, whether it’s a Hardwood or Softwood.
Not totally sure of the question you are asking ?
Yes, people placo to much. Awful stuff. Some do it well and and some don’t.
There are a lot of ‘easy’ skimming plasters (enduit) available in France which allows people to do it themselves.
I use 90% of the time Beton cellulaire and then skim it. Proper wall. Or beton celluaire then placo it. Depends how I feel on the day.
Depends what your wall is made of and what finish you want - all my external walls and most of my internal walls are stone so some of them are plastered, some ‘plastered’ with stuff like very smooth papier-maché, some just pointed and sealed with breathable anti-dust stuff, some have a marine placo lining eg my utility room and larder etc so it really boils down to what you want the final layer to look like. Not one of my walls is vertical so even if I liked wallpaper, which I don’t, I wouldn’t be able to put any up without placo as a base because plastering with a view to subsequent papering isn’t a very realistic option on walls like that.
Aon I quite agree with you. I have fitted high performance UPVC to my 200 year old house. Reason low maintenance, high performance, perfect weather seal and Im leaving the house to my grandchildren. The City and Guilds Little Englander doesn’t know what he is talking about in terms of owning and living in France. Completely out of his depth and cant stand it when everyone doesn’t immediately obey his shouted orders.