Sustainability is a strategic priority. With a growing number of regulations on the horizon, pressure from stakeholders, and rising internal ambitions, companies are expected to act, and fast. But building a full in-house sustainability team takes time, budget, and clarity. Integrating ESG across a business is complex work. Even companies with clear ambitions can struggle to prioritize the right capabilities at the right time. It often requires temporary expertise to build internal capacity or accelerate progress.

That’s where interim sustainability managers come in.

They’re the boots-on-the-ground experts who can step in quickly, bring structure and momentum, and help you move from ambition to action. Whether you need to shape your sustainability strategy, prepare for your next sustainability report, or guide internal change.

In this guide, we’ll walk through what interim sustainability managers do, when to bring one on board, and how to get the most out of working with one.

What Is an Interim Sustainability Consultant?

As sustainability climbs the business agenda, many companies are looking for hands-on expertise without the delay or cost of a lengthy hiring process. That’s where interim sustainability consultants come in.

Sustainability or ESG spans climate action, resource efficiency, social impact, and governance. It’s about aligning business with long-term resilience and responsibility. Clients, investors, regulators, and employees are all raising their expectations.

A sustainability consultant helps organizations translate ambition into action. They define priorities, shape strategy, set KPIs, and ensure progress is backed by data. Many also strengthen internal systems, prepare ESG reports, or build internal awareness through training and workshops.

An interim sustainability consultant brings that expertise exactly when it’s needed. They step in temporarily to fill a capability gap, lead a critical project, or build momentum when internal capacity is stretched.

These professionals typically work on a short-term or project basis, either part-time or full-time. Many combine in-house ESG experience with a consulting mindset, which means they can hit the ground running, adapt quickly, and deliver real impact from day one.

What Do Interim Sustainability Consultants Do?

An interim sustainability consultant helps businesses turn ESG commitments into action quickly and effectively.

They bring targeted expertise to fill short-term gaps or deliver specific outcomes. Common responsibilities include

• Developing or refining ESG strategy: Aligning sustainability goals with business priorities.
• Preparing ESG reports: Supporting CSRD, GRI, or other frameworks with solid data and storytelling.
• Conducting gap analyses: Identifying where the company stands and what needs to change.
• Setting KPIs: Helping teams choose meaningful, measurable indicators of impact.
• Launching sustainability initiatives: from climate transition plans to circularity pilots.

These consultants often step in during busy periods (e.g., reporting season), complex transitions (e.g., mergers or supply chain shifts), or when new expertise is required (e.g., biodiversity or life cycle assessments).

They don’t just give advice; they roll up their sleeves, embed themselves into your team, and get things done.

Why Should You Hire an Interim Sustainability Consultant?

Sustainability teams are often stretched thin, especially as expectations grow from regulators, investors, and customers. An interim sustainability consultant can give you the boost you need, exactly when you need it.

Here’s why it might be a smart move:

• Quick, Flexible Support

Hiring full-time staff takes time. Interim consultants can step in within days to lead a project, cover someone’s leave, or move things forward while you’re still hiring.

• Access to Specialist Expertise

Most in-house sustainability roles are broad. But what if you suddenly need to tackle CSRD readiness, run a biodiversity assessment, or calculate Scope 3 emissions? Interim consultants bring deep expertise on niche topics, fast.

• Cost-Effective

Compared to big consultancies, interim consultants are leaner and often more transparent. You pay for the work, not the overheads. And because they’re experienced, they usually deliver value faster with less hand-holding.

• Local and Industry Know-How

Need to comply with local regulations in a new market? Or speak the language of your industry? Many interim consultants have cross-sector experience or local insights that internal teams may lack.

• Fresh Eyes, No Baggage

An external consultant brings objectivity. They can spot blind spots, challenge assumptions, and help you avoid reinventing the wheel.

When Should You Consider Hiring an Interim Sustainability Consultant?

Not every moment calls for external support, but when the pressure is on, an interim sustainability consultant can be a lifesaver. Here are the most common moments when bringing one in makes real business sense:

1. You’re Racing Against a Deadline

CDP questionnaire due in 6 months? B Corp reassessment looming? Supply chain data overdue? Interim consultants can help you meet time-sensitive ESG demands without burning out your team.

2. You’re Understaffed

Maybe your sustainability lead just left, went on maternity leave, or you simply don’t have the internal capacity to handle everything at once. Interim consultants fill the gap without long-term commitments.

3. You’re Dealing With Complex Regulations

From EU regulations like EUDR to region-specific compliance needs, many sustainability regulations require specialist know-how. Interim consultants bring that legal fluency to your project.

4. You’re Launching Something New

Whether it’s a climate strategy, a responsible sourcing framework, or an ESG training program, big launches may need extra hands. A consultant can help design, roll out, and optimize your efforts.

5. You Need a Deep Dive

Sometimes you need to zoom in: a supply chain risk scan, a materiality assessment, or a biodiversity impact review. Interim consultants bring targeted experience for these one-off (but essential) projects.

How to Hire an Interim Sustainability Consultant

Hiring the right interim sustainability consultant doesn’t need to be complicated, but it does require a bit of preparation. Here’s how to make sure you find the right fit and get value from day one:

1. Define What You Actually Need

Before jumping into a search, get clear on the scope. Are you looking for reporting support, regulatory guidance, stakeholder engagement, or all of the above?

Clarify:

• What problem needs solving
• What skills are required
• The expected deliverables and timeline
• Whether the role is part-time or full-time

Having this mapped out will make it much easier to identify the right person.

2. Use the Right Channels

You can find consultants through platforms like Dazzle (sustainability-specific), Leafr, or general freelancer marketplaces. For high-quality matches, platforms like The Overview Effect help you connect with vetted experts who understand both the field and your industry.

You can also lean on your professional network; word of mouth still goes a long way.

3. Check Credentials and Fit

Experience and cultural fit matter, so it’s best to look for someone who has:

• Relevant sector experience
• Familiarity with your reporting standards (EUDR, CSRD, etc.)
• Strong communication skills
• The ability to work independently and adapt quickly

Ask for case studies, not just CVs. A good interim consultant should be able to show how they’ve delivered impact in similar settings.

4. Set Clear Agreements

Agree upfront on scope, deliverables, timelines, and budget. Define how you’ll work together (e.g., weekly check-ins, shared docs). This keeps everyone aligned and avoids surprises.

Tips for Working Successfully with an Interim Sustainability Consultant

Bringing in an interim consultant can be about getting tasks off your plate, but it is also about unlocking momentum.

Here’s how to make the most of the partnership:

1. Start with a Clear Scope

Even if the work evolves over time, make sure you both start on the same page. What does success look like? What’s in (and out of) scope? Clear expectations upfront = fewer surprises later.

2. Keep Communication Flowing

Set up regular check-ins, even if things are going well. A 15-minute weekly call can help flag issues early, keep priorities aligned, and build trust.

3. Treat Them Like Part of the Team

Give them access to the right people, tools, and context. The more they understand your business, the better their work will land. Bonus: they’ll be more likely to transfer knowledge as they go.

4. Focus on Practical Outcomes

Avoid getting stuck in strategy loops. Prioritise action over planning, whether it’s developing a dashboard, finalising a report, or equipping your team through training.

5. Plan for the Handover

Every interim role ends, so its important to think ahead about who will own the work next, and make time for documentation, training, or internal debriefs. The goal isn’t only to deliver a project, it’s also to leave your team stronger, and more equipped.

Typical Process: How Interim Sustainability Consultants Work

Every business is different, but most interim consultants follow a structured process to help you move from ESG ambition to action. Here’s what that usually looks like:

1. Establishing a Baseline

The first step is understanding where you’re starting from. The consultant will review your existing sustainability activities, reporting practices, and available data to assess your current sustainability efforts. This helps identify strengths, gaps, and the maturity of your ESG efforts.

2. Aligning Goals and Strategy

Once the baseline is clear, you’ll work together to define where you want to go. That could include setting climate targets, improving supplier policies, or aligning with reporting frameworks like GRI or CSRD. The consultant helps translate those goals into a practical roadmap.

3. Setting KPIs and Building Systems

With the direction set, it’s time to track progress. Your consultant will help define meaningful KPIs, map out how to collect the right data, and improve internal processes so reporting and decision-making become easier over time.

4. Delivering Reporting or Projects

This is where things get real. Depending on your priorities, the consultant might help prepare your ESG report, build an internal dashboard, conduct a gap analysis, or train internal teams. They stay focused on delivering tangible, usable outcomes.

5. Continuous Improvement & Handover

Good sustainability work is never one-and-done. Interim consultants often wrap up with recommendations for continuous improvement and, if needed, help with handover or onboarding a permanent hire to carry the work forward.

Conclusion

Sustainability work is evolving fast, and businesses need to be dynamic in order to move with it. But you don’t always have time to hire, train, and scale an internal team before the next ESG deadline hits. That’s where interim sustainability consultants offer real value. They bring expertise, momentum, and flexibility. Whether you need someone to lead a project, close a skills gap, or help your team navigate new regulations, interim support enables you to move faster without compromising quality.

The key is knowing when to bring someone in, how to choose the right fit, and how to make the most of the time you have together. Do that well, and you’ll not only meet your sustainability goals, but you’ll build the internal capability to keep growing long after the contract ends.