The Ministry of Business, Innovation and Employment (MBIE) is going ahead with a restructure which splits its building watchdog into two parts.
The role of chief architect has been replaced by a principal advisor position in the overhaul.
Architects Institute president Christina van Bohemen said the ministry would still have a chief engineer and a chief scientist, and she could not understand why it would downgrade the chief architect's position.
She questioned how the change fitted with the Canterbury Earthquakes Royal Commission recommendation that there be close collaboration between engineers and architects to make buildings safer.
"There's a lack of understanding of the breadth of architectural involvement in the making of buildings," Ms van Bohemen said.
"As the Grenfell [Tower] fire discussion makes evident, it's a really complex process."
She said regulators had to have a "really keen understanding" of how architects were involved all the way along and needed to work closely with engineers from the word go.
A ministry email yesterday confirmed the restructure, which adds 22 new jobs.
In the split, what remains of the Building System Performance branch will focus on policy, and its more hands-on functions will be put in a different part of the ministry.
The branch's general manager, Anna Butler, said the aim was to to ensure the branch was focused on the right activities and had the right supporting structure.
Building Minister Nick Smith said the structure was up to the ministry, not him, but he expected it to lead to improvements in policy-making, technical skills and the resources to deal with product and system complaints.