The new law was introduced in June and requires a stricter design review by building officials.
Previously, qualified architects could sign the approval documents for a building regulation application but now engineers are required to sign under the new law.
The law comes in the wake of a scandal involving a Japanese architect who falsified quake resistance data to reduce costs.
There was previously no specific professional license for structural engineers in Japan – they first qualify as ‘first class registered Architects’ and then study further to specialise as structural engineers.
"The law affects all consultants who design buildings in Japan. There are very few foreign firms who have staff qualified to sign documents so most collaborate with a local firm," said Arup Europe chairman Philip Dilley.
"From what I understand the new law means that a "qualified" engineer must be involved in all projects – this will probably affect the smaller ones more since the larger complex projects would always have an engineer in any event."