For the architect

Planting on the balcony. Plants on the balcony and roof terrace: build planters or buy loose pots? If large planters are built, how should they be waterproofed? The household has little time for cleaning - should a balcony be built at all?

Exterior walls without stains from rain water - what solution?

Overflow drain pipes on the roof terrace, outdoor area upstairs, balcony: not sure the household will be diligent enough to clean the drain pipes, leaves may clog them - what solution?