He said: "At the beginning, the Scottish parliament was perceived to be a low-level target, but that is now under review."
Changes could also be ordered to other buildings on the drawing board and those already underway, including the Welsh assembly, GCHQ in Cheltenham and the Greater London Assembly HQ.
Alan Mack, Bovis Lend Lease's project manager at the Scottish parliament, said there would be an impact, as security is an issue people will take more seriously now.
He said rules would continue to change in the light of recent atrocities and some security areas on the Scottish parliament building might need to be reinforced.
The events in New York have led to a surge in calls to engineers, as clients seek advice on how to improve building security.
Building security is suddenly on the agenda
Steve Tanno, facades director
Buro Happold facades director Steve Tanno said the New York attack had worried clients. He said: "It has suddenly appeared on the agenda, particularly for commercial projects. For jobs we did a year or two ago, clients are now coming back to us to talk about it."
It is standard procedure for the government to review security of its buildings after terrorist attacks.
The attack on the Murrah Federal Building in Oklahoma City in 1995 led to new regulations to reduce the risk of flying glass, which accounts for 90% of bomb injuries.
John Haddon, director at Arup Security Consultants, said clients in London were seeking advice.
