Architect supplying goods with service

An architect registered for GST as a service provider supplied construction goods (like TMT bars) along with their consultancy services. The advice given is to invoice these goods at the applicable 18% GST rate and include their HSN codes. Crucially, the architect's GST registration needs to be amended to reflect the supply of both goods and services, changing the 'nature of business' from solely 'supplier of service' to include goods.