Barn conversion - technical start

[John_1919]

I am considering applying for PP to convert a 1980's vintage barn [steel frame, single skin concrete block walls, corrugated roof] to self contained domestic use.
Making a technical start which has the minimum of external visual impact to keep the PP alive and then just keeping it as a long term investment.
For an existing building of this type, what sort of minimally visually intrusive works are likely to be accepted as a technical start ?

 

[freddiemercurystwin]

Underground drainage or foundations, in anycase both ought to have building regs inspection thus creating a paper trail, worth keeping planning up to speed with things as they're the ones who'll need to be satisfied.