Authorised materials
It is a precise term. The precision is the point.
This page explains what it means before it explains the detail.
01
An authorised material is one that has been specified by HERU as suitable for operation within a HERU unit, to be retained by the building that generated it and placed into the unit in accordance with the prescribed operating method.
Authorisation is a decision made in advance by HERU — not a judgement made at the unit by whoever happens to be standing next to it.
02
A system that accepts anything cannot make promises about anything. Defining the inputs is what allows the outputs, the operating conditions and the performance of the unit to be specified and relied upon.
It also makes the intention explicit. The building retains these materials in order to recover useful heat from them. That intention is deliberate, documented and consistent.
03
Authorised materials and the prescribed operating method work as a pair. Specifying what may go into the unit means little without also specifying how the unit is operated.
HERU specifies both. The unit is installed, commissioned, operated and maintained to that specification, by people trained on it — in the same way as any other item of building plant.
04
Most of what a building generates is intentionally not appropriate for a HERU unit—and is not intended to be. Suitability depends on the behaviour of a material under the prescribed operating method, and on whether recovering value from it on-site makes sense at all.
Being clear about what HERU is not designed to do is as important as being clear about what it is.
Everyday examples
HERU has been designed to operate only with specifically authorised materials that have been validated for use in accordance with HERU’s prescribed operating method.
The full examples are set out in a separate document. They are illustrative rather than exhaustive, and the authorised materials schedule will continue to evolve as engineering validation progresses.
HERU has not been designed to operate with every material generated within a building. Materials are authorised only where they fall within HERU’s validated operating envelope and prescribed operating method.
Engineering principle
HERU authorises materials through engineering validation—not simply by the name, composition or category of a material.
Every authorised material has been assessed to ensure it can be safely and reliably used within HERU’s prescribed operating method while maintaining system performance, emissions compliance and long-term integrity.
The examples above are intended to explain the types of materials authorised for HERU and do not constitute the complete engineering specification.
Engineering standards
The complete authorised materials schedule forms part of HERU’s prescribed operating method. The examples shown on this page are provided to explain the types of materials currently authorised for HERU.
HERU has not been designed to accept everything. It has been engineered to operate safely, predictably and efficiently with specifically authorised materials intentionally retained by the holder for a further prescribed purpose.
That engineering discipline is fundamental to the performance, safety and integrity of every HERU system.
