Heavy Vehicles are vehicles whose weight exceeds 4.5 tons
The National Heavy Vehicle Regulator (NHVR) has classified the type of heavy vehicle modifications that require approval, either by an Approved Vehicle Examiner (AVE) or the NHVR. For minor modifications (that don't require approval) the NHVR cannot provide an exhaustive list, but general guidance is provided below on the limited type of modifications classified as minor.
Minor modification:
Minor modification includes the fitting of optional equipment or alterations to a vehicle within manufacturer’s specifications that do not cause the vehicle to be non-compliant with heavy vehicle standards. Should clarification be required on whether a modification requires approval the NHVR will make a determination.
Examples include; additional lighting, aerials, air conditioning, alarm systems, plastic shields for lamps and windscreens, and manufacturer’s wheel and tyre options (that do not affect the Gross Vehicle Mass (GVM) or Gross Combination Mass (GCM) rating of the vehicle). These modifications do not require approval provided the vehicle continues to be within manufacturer’s specifications and comply with the heavy vehicle standards.
Modifications under the Code of Practice - require approval by an AVE
This includes complex modifications that can affect the safety of a vehicle if not performed properly. The modifications included in the Code are based on accepted vehicle engineering practices and the requirements of the heavy vehicle standards. The Code also supplements the recommendations of the original vehicle manufacturer in relation to vehicle modification techniques or standards and provides guidelines where manufacturer’s specifications do not exist.
The Code applies the existing National Code of Practice Vehicle Standards – Heavy Vehicle Modifications.
Vehicles modified in accordance with the Code maintain the vehicle’s compliance with the heavy vehicle standards. These modifications require approval by an AVE who will issue a modification certificate and ensure a modification plate is affixed to the vehicle if the vehicle passes inspection. The vehicle may require a further inspection subject to particular jurisdiction registration laws.