The listed company - run by Stewart McColl - can now claim to employ a total of 416 architects, following a series of five takeovers which were announced to the stock market today (25 September).
At the time of the last AJ100 (AJ 04.05.06), BDP, the perennial number one, employed just 281 qualified architects.
And, amazingly, SMC has also become the largest firm in Scotland, from a position yesterday where it employed no-one north of the border.
The hugely acquisitive firm has bought Edinburgh- and Glasgow-based Parr Architects, formerly the Parr Partnership, which on its own sat at 72 in this year's AJ100.
In addition, McColl's company has also snapped up the Hugh Martin Partnership, Davis Duncan Architects and Jenkins and Marr, all in Scotland.
The firm has also strengthened its position in the Midlands by buying Birmingham's Hickton Madeley Architects.
Despite the extraordinary achievement of five take-overs in one morning, McColl insists that his hunger for acquisitions is not sated.
'This is only the beginning,' McColl told the AJ. 'Providing we continue to satisfy shareholders and we don't make a stupid mistake, then this will definitely continue.
'We expect to have a turnover for 2006 of £34.7 million, with a £7m profit,' he went on. 'And you can expect more takeovers within the year.
'But the nature of what we do is to have a light-touch approach. We are buying businesses that are well run. We do not need to interfere with them,' he added.