​Been offered a 1/3 stake in a company I’d build from scratch and run solo – is this fair or am I giving away too much?

Hey everyone, I’d love some advice on a business partnership offer I received.

Background: I’ve been working in IT for years (earning €2,800/month net) and have been slowly building experience in electrical installations on the side through a sole trader business, working with my brother, father and a few friends. Currently doing about one project per month (~5 days of work), building my client base and reputation. I also have €50,000 in savings ready to invest in starting a proper company.

The offer: Two friends of mine (they’re brothers) run a successful construction company with ~50 employees and several related businesses in the sector. After I completed a project for them, they approached me with a proposal to open an electrical installation company together, with plans to expand into full MEP (mechanical, electrical, plumbing). The ownership structure they proposed is 1/3 each – so they together hold 2/3 and I hold 1/3. I would run the entire company operationally, while they would provide administrative support (finance, HR) through their existing company, funded via interest-free loans that would need to be repaid.

My concerns:

They are two people sharing 2/3, meaning they always vote as a block and I’m always outvoted – despite running everything.

The financial risk for them is relatively low (interest-free loans, existing infrastructure), while I would be leaving or reducing my IT career.

Without me, this company simply cannot exist – I bring the license, the expertise, the operational work and my own capital.

I could realistically start this company on my own using my savings.

My counter-proposal idea: I’m open to having them as partners because we’re close friends and I want to work alongside their construction projects long-term. But I feel a fair structure would be 60-65% for me and 35-40% for them together. They bring the network and administrative support; I bring everything else including my own capital.

Alternative I’m considering: Open the company myself (100% ownership) and instead sign a long-term subcontracting agreement with their construction firm, making me their preferred electrical/MEP contractor without any shared ownership.

My questions:

– Is a 60-65% / 35-40% split reasonable given this situation?

– How would you approach the counter-proposal conversation without damaging the friendship?

– Is the subcontracting agreement alternative actually smarter long-term?

– What are the biggest red flags I should watch for in the partnership agreement if I do go ahead?

Thanks in advance, I really appreciate any perspective from people who’ve been through something similar.