Im just wanting to know about paint prepwork required on the outside of the house.
The existing paint is probbably late 70's at a guess and seems to be simialr in finish and look to Enamel paint that ive seen on doors.

The house has been rendered, the render has a few chunks missing but i know how to fix these.

I want to paint a texture coat on the house to bring it up to a more modern look, what do i have to do to prep the paint surface?