Verification of bidder eligibility

Verification of bidder eligibility

Gütesicherung Kanalbau RAL-GZ 961 is a system, introduced by clients and contractors, for verifying the qualifications of executing companies and tendering and construction monitoring bodies. Clients and awarding bodies use this system to verify the technical performance capability of bidders in the competitive tendering procedure and to ensure systematic quality assurance in the execution of services.


In complying with the requirements of the Quality and Test Specifications RAL-GZ 961, bidders demonstrate their particular technical qualifications (specialist knowledge, technical performance capability and reliability in terms of technical fulfilment of the contract) as required by clients, particularly for the awarding of contracts for construction services within the meaning of section 6a no. 3 of the German Construction Contract Procedures (VOB/A)

Advice on verifying bidder eligibility in the regulations

Many standards, worksheets, bulletins and information leaflets set out requirements on the eligibility of companies for the assembly and maintenance of drains and sewers. These documents also contain advice on the awarding of contracts to eligible bidders within the meaning of the VOB.


The requirements concern the specialist knowledge, performance capability and reliability of the bidders. Verification of compliance with these requirements in the individual case entails considerable expense for the bidders and clients concerned. The technical regulations and corresponding information sheets therefore contain advice on verifying the qualifications of bidders with reference to Gütesicherung Kanalbau RAL-GZ 961. Experience has shown that taking this advice on board is very helpful for reducing the cost for all stakeholders while at the same time improving the equal treatment of bidders.


Advice on verifying bidder eligibility can, for instance, be found in:

European DIN standards:

DIN EN 1610

DIN EN 12889


DWA worksheets / bulletins:

DWA-A 125

DWA-A 139

DWA-A 142

ATV-M 149-5

DWA-M 197


Other regulations:

Arbeitshilfen Abwasser [sewer work guidelines]

EKVO Hessen