It's not a moat, it's a pond. A moat would
surround the building.
I like that the architect is incorporating a Faraday cage into the design, thats pretty clever.
Also there's this little bit of BS:
$1:
It also does not include the 17.5 per cent VAT demanded by the Treasury on all buildings in Britain and which the US has refused to pay.
Under international law an Embassy and the residences of key staff and the property of a head of state are the sovereign soil of the nation to which it belongs. Therefore, the Embassy is NOT in the UK and the US is correct in not having to pay any taxes to any level of government in the UK.
If the Brits wish to dispense with that diplomatic nicety I'm sure that Washington, DC will be pleased to send them a property tax bill and then the Queen can start paying taxes on her vast holdings in Kentucky and Wyoming.