VAT Disaggregation

A sole trader (decorator) is setting up a limited company to keep building projects seperate.

The limited company will have minority shareholdings of 5% each by the individuals two children.

If combined turnover is greater than the VAT registration limit is there a risk of being attacked?

Are the trades sufficiently commercially different?

Does the minority shareholdings help in this regard? (This is done to hopefully provide for the future generation on a future sale etc)