The move - which has seen it snap up Ian Penrose Architects and Covell Matthews Architects - takes the total number of practices bought since SMC was floated in May to five.
The Penrose deal - worth £2 million - will see the SMC group expand into the South West, and the £2.1 million Covell Matthews takeover will bring it into Cambridgeshire.
These acquisitions form a major part of chief executive Stewart McColl's plans to aggressively grow SMC Group into a practice with national coverage.
He has also stated in the past that he is determined to take the group into every major architectural sector.
McColl said of the two deals: 'We are delighted to welcome Ian Penrose Architects and Covell Matthews to the stable of SMC companies.
'Both acquisitions will be earnings enhancing and we expect them to generate value for our shareholders.
'They also increase our geographic footprint, which has particular relevance to education projects, specifically related to the Building Schools for the Future programme on which a local presence is deemed advantageous,' he added.