Questions to Ask When Comparing Contractors

Three quotes land in your inbox. Prices differ, layouts differ, and the covering letters all sound confident. Making a sound contractor comparison is difficult unless you ask the same questions of everyone and write down the answers. This checklist gives you those questions, grouped by theme, with notes on what a good answer looks like and when to be wary. It suits engineering, fabrication, building services and general industrial work. Adapt it to your job and keep the answers on file.

How to use this checklist

1. Send the same brief and the same questions to every bidder. See how to write a clear engineering brief.
2. Ask for answers in writing so that you can compare them.
3. Score each answer (for example 0 to 3) and add comments.
4. Weigh the sections according to what matters for your project; price might be 30 per cent of the decision, safety and competence far more in some cases.
5. Follow up anything vague, and keep a note of conversations.

Section 1: Who are they?

• Who exactly will be the contracting entity? Check the legal name, company number and registered address at Companies House.
• How long have they traded, and have they changed names? A history of rebranding after financial trouble deserves a closer look.
• How many people work for the firm, and how many will work on our project? Match capacity to the job.
• Do they use subcontractors? For which parts, and will you tell us who they are? Subcontracting is normal, but you should know about it and how it will be managed.
• Who will be our single point of contact? And who covers when that person is absent?

Good answer: clear, verifiable details and an openness about subcontracting.
Red flag: evasiveness about company identity or who does the work.

Section 2: Experience and track record

• What similar projects have you completed in the last few years? Ask for scale, sector, and complexity.
• Can we speak to two or three recent clients? Then do it.
• Have you worked on sites like ours (live production, food-safe areas, restricted access)?
• Describe a project that went wrong and what you did about it. Honest firms have an answer.
• Have you ever failed to complete a contract, or had one terminated?

Good answer: specific examples, with names of referees who are willing to talk.
Red flag: only generic claims, or reluctance to supply references.

Section 3: Competence and qualifications

• What qualifications and registrations do the people doing the work hold? For electrical, gas, pressure, lifting or welding work, ask for evidence rather than assertions:.
• What management-system certifications do you hold (for example ISO 9001, ISO 14001, ISO 45001)? And how do they apply on a project like ours?
• How do you handle design responsibility? Who checks calculations, who signs off drawings, and do you carry professional indemnity insurance for design?
• How do you train and supervise less experienced staff?
• Do you hold accreditation from relevant trade bodies or prequalification schemes?

Good answer: named people, documented competence, clear responsibility.
Red flag: certificates that do not match the company name or the work in question.

Section 4: Health, safety and environment

• Can we see your health and safety policy and examples of risk assessments and method statements for similar work?
• What is your accident and incident record, and have you received any enforcement notices? Ask what they changed afterwards.
• How will you comply with the Construction (Design and Management) Regulations 2015 on this project, if they apply?.
• How do you induct staff and visitors, and manage permits to work (hot work, confined spaces, working at height)?
• What is your approach to waste, noise, dust and environmental protection?
• Who is the named competent person for health and safety on our job?

Good answer: proportionate, project-specific plans and examples.
Red flag: generic documents with another client’s name still in them, or dismissive attitudes to safety.

Section 5: Insurance and financial standing

• Please provide current certificates for employers’ liability, public liability, and (where applicable) professional indemnity, product liability and contract works. Check limits, dates and the named insured.
• Are there any exclusions relevant to this work?
• Will you be able to meet our minimum cover levels?
• Can you show recent accounts or provide a credit reference? For larger projects, assess financial stability.
• Do you offer any performance bond, parent company guarantee or retention arrangements?

Because the right limits depend on the project, discuss them with your own insurer or broker before inviting bids.

Good answer: certificates provided immediately, with limits at least equal to your requirement.
Red flag: “it’s being renewed” with no evidence.

Section 6: Scope, price and commercial terms

• What is included in the price and what is not? Ask for a line-by-line breakdown.
• What assumptions have you made? Site access, ground conditions, existing services, power supply and so on.
• How are variations priced and agreed? Day rates, mark-ups and approval process.
• Is the price fixed, provisional or time-and-materials? And what is the validity period of the quote?
• What are your payment terms and any deposit requirements? Prefer payments tied to milestones.
• Do you apply retention, and when is it released?
• What are the consequences for late completion?
• Which standard contract or terms do you propose?

Good answer: transparent, itemised pricing with clear exclusions.
Red flag: a single lump sum with no breakdown, or heavy up-front payment requests.

Section 7: Programme and resources

• What are your proposed start and completion dates, and key milestones?
• What lead times apply to major equipment or materials, and how have you verified them?
• What do you need from us, and by when? Access, decisions, information, services.
• How will you handle delays outside your control (weather, deliveries, access)?
• What labour will be on site and for how long?
• How do you propose to manage work in a live site with our own operations?

For help creating a realistic programme yourself, see how to prepare a project budget and timeline.

Good answer: a logical programme showing dependencies and risk allowances.
Red flag: an unrealistically short programme designed to win the contract.

Section 8: Quality, testing and documentation

• How will you check quality during the work? Inspection and test plans, hold points, witness testing.
• What documents will you hand over? As-built drawings, manuals, certificates, test results, risk assessments.
• How will you deal with defects and snagging?
• What training will you give our team?
• How will you keep our drawings and data confidential?

Good answer: a defined handover pack and quality plan.
Red flag: “we’ll sort the paperwork afterwards”.

Section 9: Warranty and aftercare

• What warranty do you offer, and what does it cover and exclude?
• How long is the defects liability period?
• What is your response time for faults after handover?
• Do you offer maintenance or service agreements, and are they separate from the project price?
• What happens to the warranty if someone else services the equipment?

Good answer: written warranty terms and named support routes.
Red flag: verbal promises only.

Putting it into a scorecard

Set the weights before you see the prices, so you are not tempted to reverse-engineer a preference. Where there is a pass/fail requirement, such as valid insurance or required qualifications, treat it as a gate rather than just another score. When two firms score closely, a short interview or site meeting often decides it. For the full selection process, read how to choose an engineering contractor.

Frequently asked questions

How many contractors should I compare?

Three to five is usually enough to give you a meaningful comparison without overwhelming you.

Should price be the main factor?

Price matters, but value depends on competence, safety, programme and aftercare. A low price on an incomplete scope is not cheap.

What if all quotes are higher than expected?

Review scope and assumptions, ask bidders to price options, and consider phasing the work. Don’t squeeze price by cutting safety or commissioning.

In-House vs Outsourced Engineering: Pros and Cons

Conclusion

A consistent set of questions turns a gut-feel decision into an evidence-based one. Ask about identity, experience, competence, safety, insurance, commercial terms, programme, quality and aftercare, score the answers against weights you set in advance, and follow up the vague ones. The few hours it takes will probably save much more than that across the life of the project.