KEY POINTS
- Compare proposals against the same written scope.
- Ask for evidence relevant to the work, rather than general credentials alone.
- Agree how changes, test findings and aftercare will be managed.
The most useful contractor comparison connects the quotation to the people, work methods and records needed for your project. Give each bidder the same drawings and site information, then use these twelve questions to identify omissions and resolve differences.
1. Who is responsible for engineering decisions?
Ask who prepares, checks and approves the design and who supports site changes. Where regulated engineering work is involved, verify the relevant licence and permitted scope through the Council of Engineers. Confirm whether the responsible engineer is an employee or an appointed consultant.
2. Which requirements form the design basis?
Request the applicable standards, editions, utility requirements and client specifications. A named standard is useful only when its relevance to the equipment or installation is clear. For example, IEC 61439-1 addresses low-voltage switchgear and controlgear assemblies; it is not a substitute for the complete installation design.
3. What comparable work can the team demonstrate?
Look for experience with similar equipment, site restrictions and responsibilities. Ask what the contractor actually did on each reference project. A role in one work package should not be confused with responsibility for the whole facility.
4. Who coordinates utility and owner approvals?
Identify the applicant, document owner and technical contact. If supply capacity must change, confirm the required application and inspection steps before agreeing an energisation date.
5. What design records are included?
List the drawings, calculations, equipment schedules and revisions required. Agree which are issued for review, construction and final handover, and whether editable copies are needed.
6. How will shutdown work be planned?
Ask for the proposed approach to isolation, affected loads, work sequence, authorisation and return to service. Agree review points and fallback arrangements with the operations team.
7. How is temporary supply scoped?
If required, define supported loads, connection arrangements, equipment responsibilities and the changeover plan. Do not assume a generator quotation includes every connection or operational task.
8. What tests demonstrate acceptance?
Agree the applicable tests, acceptance criteria, witness points and report format. Records should identify the equipment, results, instruments and responsible people. Test selection must fit the installation; one generic list is not appropriate for every job.
9. How does the team work within site safety procedures?
Review the proposed risk assessment, work permits, competence requirements and arrangements for isolation and access. Confirm how subcontractors and equipment vendors are included.
10. Who owns inspection and maintenance records?
For factory work, confirm the applicable obligations under the electrical-safety regulation, the inspecting party and the records the operator will retain. State statutory certification separately if it is required in the contract.
11. How are prices and variations documented?
Compare inclusions, exclusions, provisional items, taxes and payment milestones. Agree a written process for changes to scope, price and programme. A lump-sum offer can be valid when its scope is clear; the format alone does not establish value.
12. What happens after handover?
Confirm the arrangements for defects, warranty queries, maintenance and additional work. Ask which response commitments are included and which require a separate service agreement.
Turn the answers into a comparison
Record each bidder’s evidence, unresolved questions and exclusions against the same scope. Compare the cost of a complete, coordinated package instead of filling gaps with assumptions. ETES’s service overview and project references can support an initial scope discussion.
Common questions
Must the engineer be a permanent employee?
Clarify the appointment, authority and availability of the responsible engineer. Employment status alone does not demonstrate the quality or completeness of the engineering work.
What is a reasonable maintenance price?
Compare the equipment, visit frequency, tasks, consumables, exclusions and response arrangements. A fixed percentage of the original installation cost is not enough to establish a suitable maintenance price.
How much time should selection take?
Allow time for the site review, technical clarifications and proposal comparison. Set the period around the scope and information available, rather than a universal number of weeks.
ETES services for this work
References & further reading
Primary publications used in this guide. Confirm the requirements and editions applicable to your project.
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