Short answer: A sustainability consultant should take a defined job off your plate. They may interpret a customer request, build a greenhouse gas (GHG) emissions baseline, prepare a report or rating submission, build a strategy, or run the work as a part-time team. You are most likely to need one when the request is new, the answer requires judgment, the deadline is real, or nobody inside your company owns the work. Pricing may be based on time, a fixed project, or ongoing support. Keslio publishes a starting fee or typical range for each company service, shown below.
The title may say sustainability consultant or ESG consultant, short for environmental, social, and governance work. Ignore the label for a moment. Start with the job sitting on your desk, the person who needs the answer, and the date they need it.
What does a sustainability consultant do?
A good consultant turns an unclear ask into a defined piece of work. They work out what the answer must contain, which data matters, which method to use, who needs to provide input, and what you should receive at the end. The work usually falls into a few concrete jobs.
- Build an emissions baseline. This means gathering company data and calculating direct emissions, purchased-energy emissions, and the relevant parts of the value chain, usually called Scope 1, Scope 2, and Scope 3. The result should include the method, assumptions, and evidence behind the number. See Keslio's GHG Emissions Calculations service. If you only need a first screening estimate, start with the free GHG emissions calculator.
- Answer a customer or platform request. A consultant reads the exact wording, identifies what is actually required, gathers the data and proof, and prepares the response in the format the customer or platform expects. Keslio's Supplier Request Support is built for this job.
- Prepare a sustainability report. The work can include choosing the right framework, planning the data collection, checking claims against evidence, writing the report, and preparing it for publication. See Reporting and Communications.
- Support a rating, certification, or disclosure. This can mean preparing an EcoVadis assessment, a CDP response, a certification application, or another evidence-based submission. The consultant should map the requirements, organise the proof, support follow-up questions, and show you where the gaps are. See Ratings and Certifications.
- Build a sustainability strategy. A useful strategy sets priorities, targets, owners, and dates that fit the business. It should help your team decide what to do, not just describe ambitions. See Keslio's Sustainability Strategy service.
- Act as your part-time sustainability team. If requests, reporting, ratings, and data work keep returning but do not justify a full internal team, ongoing support gives someone clear ownership. See the Fractional Sustainability Team.
You can compare these jobs on Keslio's sustainability services page. The useful question is not whether a consultant can do sustainability work in general. It is whether they can deliver the specific answer, report, calculation, submission, or operating support you need.
Do I need a sustainability consultant?
You probably need help when the work is unfamiliar and someone outside your company will rely on the answer. That could be a customer, investor, platform, board, or auditor. The case for help gets stronger when the request is unclear, the data sits across several teams, the method involves judgment, or the deadline leaves little room to learn by trial and error.
You may not need a consultant when the task is narrow, the method is already settled, your data owners know what to provide, and your team has completed the same process before. Software can help when the main problem is recurring data collection and calculation. It cannot decide what an unclear request means or defend a judgment for you.
For the full decision, read when carbon accounting software helps and when a consultant helps. The short version is simple: use tools for a repeatable process; use experienced judgment when the process still has to be defined.
How much does a sustainability consultant cost?
First check what the price is buying. Sustainability work can be sold as a fixed project, a day rate, or a retainer or fractional arrangement. A time-based fee buys access to a person's time. A fixed project buys an agreed output and scope. A retainer buys recurring capacity over time.
Those prices are not directly comparable. One may cover advice only. Another may include data collection, calculations, interviews, writing, design, revisions, and handover. Before comparing quotes, make sure the outputs and exclusions match.
Keslio publishes the following fees for company services. The fee is confirmed before work starts, once we understand the job.
| Service | Published fee | What the fee is anchored to |
|---|---|---|
| Fractional Sustainability Team | Starting at $3000 per month | Ongoing senior capacity for strategy, GHG data, reporting, ratings, and customer requests. |
| Sustainability Strategy | Starting at $8000 | A practical strategy with priorities, targets, owners, policies, and a roadmap. |
| GHG Emissions Calculations | Starting at $3000 | A documented Scope 1, Scope 2, and relevant Scope 3 baseline with evidence. |
| Supplier Request Support | Typical range $3k-$8k | A response to a customer or platform request, from one emissions number to a fuller submission. |
| Reporting and Communications | Starting at $8000 | A report matched to the right framework, with evidence-backed claims and a finished output. |
| Ratings and Certifications | Starting at $8000 | Preparation, evidence, submission support, follow-up, and a clear view of the gaps. |
The final fee can move with company size, the number of sites or products involved, the amount of Scope 3 work, the state of the data, the reporting framework, the rating or platform, the deadline, and how much evidence still needs to be built. See the current service detail and what moves each fee on Keslio's pricing page.
Ask for the commercial terms in plain words. Is the fee fixed? What is included? What is excluded? What would trigger a change? What will you receive if the work takes less or more time than expected? A clear proposal should answer those questions before you commit.
What should a sustainability consultant deliver?
The deliverable should help you answer the request and repeat the work later. A polished presentation is not enough if the calculation, evidence, and decisions disappear when the consultant leaves.
- A written scope. It should name the question, reporting boundary, output, audience, responsibilities, timing, and exclusions.
- A clear data request. You should know what the consultant needs, who owns it inside your company, and which gaps may require an estimate or follow-up.
- A documented method. For technical work, this should identify the standard, calculation approach, emission factors, assumptions, exclusions, and review steps. For a company emissions inventory, the GHG Protocol Corporate Standard is one method you may see named.
- Working files you can use. You should receive the calculation file, evidence list, response workbook, policy set, or other working material needed to understand and refresh the output.
- The final answer in the required format. That may be a customer response, emissions inventory, methodology note, report, rating submission, strategy, policy, or management update.
- A review and handover. The consultant should explain the main judgments, unresolved gaps, next deadline, and what your team needs to maintain.
Check what the output is worth to the person receiving it. A consultant can prepare calculations, methods, evidence, and a support letter. That is not automatically independent assurance. If the request mentions verification, an auditor, limited assurance, or an independent provider, read the difference between a consultant letter and independent assurance before agreeing the scope.
How do I choose a sustainability consultant?
Use the first call to test how clearly the consultant understands your job. You should leave with a sharper problem, not more jargon.
- Who will do the work? Ask who gathers the data, builds the analysis, writes the output, reviews it, and joins your meetings.
- Have you done this exact kind of job? A strategy, first emissions baseline, customer response, report, rating, and assurance preparation need different experience.
- What will I receive? Ask for the file names or output types, not a broad promise of support.
- Which method and factors will you use? Ask how the consultant chooses standards, emission factors, boundaries, estimates, and exclusions, and how those choices will be documented.
- What do you need from my team? Ask which people and records are required, how missing data will be handled, and what could delay the work.
- Will the output answer the request in front of me? Share the exact wording when you can. Nobody should guarantee customer, platform, auditor, or rating acceptance, but they should explain how the output maps to the requirement.
- What is outside the scope? Confirm whether design, submission, follow-up questions, assurance, translation, software, travel, and annual refreshes are included or separate.
- How can the fee change? Ask whether the work is fixed-fee or time-based, what assumptions sit behind the quote, and how changes will be agreed.
Be careful if the answer depends on a vague transformation programme, a guaranteed rating, or a claim that the same template works for every company. You are buying judgment and a usable output. The consultant should be able to explain both in plain words.
What should the first 30 days look like?
The exact timeline depends on your deadline and the state of the data, but the sequence should be easy to see.
- Start with the exact ask. Share the request, intended outcome, audience, deadline, and what has already been done.
- Agree the scope and fee. The consultant should define the output, method, responsibilities, exclusions, review points, and commercial terms before the work expands.
- Gather the data and evidence. Your team gets one clear request list. Gaps and assumptions are recorded as they appear.
- Review a working output. You should see the calculation, response, report structure, strategy, or evidence pack early enough to correct the direction.
- Finish with a usable handover. You receive the final output, the supporting files, a record of key decisions, and a clear next step for the next request or reporting cycle.
If you have a sustainability request, report, rating, emissions baseline, or strategy sitting on your desk, tell Keslio what you need. We will review the job, explain what the work involves, and confirm the fee before anything starts.
