Under Templeton's plans, the two Marble Arch properties, 29 Connaught Square and 5 Archery Mews - which cost an extra £800,000 and backs onto the larger Connaught Square property - will be knocked into one massive home.
The plans are due to be scrutinised by a Westminster City Council planning committee on 3 May, and councillors will pay particular attention to a number of objections from neighbours of the Grade II-listed Connaught Square building.
The objections include concerns over intrusive CCTV cameras and the installation of solar panels and a planned roof terrace.
Despite the concerns - which were leaked to 'right of centre' political blogger Iain Dale (www.iaindale.blogspot.com) - it seems likely that the Blairs will get their home, after the council said: 'It is not considered that the scheme will have a significant impact on residential amenity.'
Major structural works aside, the renovation also includes the removal of numerous oak cupboards, shelves and wardrobes and the stripping of velvet wallpaper hung by the house's previous owner, Basic Instinct 2 director Michael Caton-Jones.
The Blairs have, however, decided that the house's cantilevered stone staircase will remain.
The renovation is scheduled to be completed by the end of June, when Tony and Cherie are expected to leave Number 10 to make way for PM-in-waiting Gordon Brown.