Offshore company VAT registration

Offshore company is beneficially owned by Saudi national who is non resident in UK. Residential flats are nearing completion and about to be let.
s there any down side to VAT registration, particularly as client does not wish to be seen to be trading. Rental income will be subject to UK tax.
Is there any benefit in splitting into a number of offshore companies (e.g. one for each flat?)
Ian Dudley