This means that you'll be able to search for NAICS codes directly (if that's your jam). We'll do the math; let's make better data on public procurement together.
Possible NAICS Codes
236220 – Commercial and Institutional Building Construction
238190 – Other Foundation, Structure, and Building Exterior Contractors
237990 – Other Heavy and Civil Engineering Construction
423810 – Construction and Mining (except Oil Well) Machinery and Equipment Merchant Wholesalers
237310 – Highway, Street, and Bridge Construction
212321 – Construction Sand and Gravel Mining