mmmm, without seeing it. it looks like effloresence (or else crap brick matching (possibly the latter)) to the lower bay sections.

The only dodgy looking areas are the lower bays and rear block section.

1. you could prep and paint the entire building - waaaaayyy cheaper than rendering.

2. You could pebble/spar/render these three areas and save a bundle of cash.

3. Render/pebble/dash the rear block section and paint the remainder

4. Render the whole thing

Your choice.

HTH? Silver