We had few cases where retirement couples have bought such rural village properties and have renovated them. They've spent few years enjoying relaxing life at the country side. But in reality not everything is as they saw it on "A Place in the Sun". When you buy a property overseas, you need to get familiar with the local legislation, concerning renovation, building etc.
A bad example for missing a planning permission
In the above case, the couple listened to neighbour's advise that they don't need any building or planning permissions when they built within the same spot where the old ruined barn was. Basically they have demolished the old barn and 'have built' it from scratch within the borders of the old one. No matter how right this may sound, it is in fact wrong. You will need to obtain a planning permission for any constructions works. Renovation in many cases may also require planning permission.
How does this affect the buyer of a rural house
The first thing to check when you buy rural house is to ask the seller whether there have been any new construction works in the plot or in the house. If there are any, ask for the planning permission documents. If the seller unable provide such, this probably means that the construction works are illegal.
Implications of illegal construction are as bad as you probably think. The construction has to be demolished either by the owner at their own expense or will be enforced by the Directorate of National Construction Control and the expenses for the demolition will be accounted on the owner.
Rural plot problems
Obviously the rural house is located in a plot within the borders of a village. Because of the 1945 nationalisation of all private properties in Bulgaria many rural plots were split, joined and then again split for the purpose of the collective agricultural unions (TKZS). After 1989 the land was returned to the heirs of the initial land owners. This caused many problems with the land plot borders as they have peculiar shapes and curves. When a foreigner buys a rural house, one of the things that also has to be check is the land plot. Make sure your solicitor checks if the seller is the only current owner of the plot and whether there is no some reserved property right left over the property (e.g. agreement for personal care and financial support). If there is some encumbrance on the plot, you either have to solve this issue or just give up buying this village house.