Before the war, he worked with wood processing, but after the start of Russia's war against Ukraine, he changed his saddle.
Hemmabunker, or the "life capsule" as he himself calls his creation, consists of five millimeter thick metal sheets joined together with bolts.
Not suitable for a direct hit
The entire construction is installed in an apartment or in an office by being attached to a load-bearing wall.
Serhij says he had the strength of the metal structure tested and says it can carry around 40 tons.
- It will last if the whole house collapses, says Serhij to SVT.
But he emphasizes at the same time that his life capsule would not survive a direct hit by a Russian grenade.
Two meters high
The protective capsule is two meters high and one meter wide, and has ventilation holes.
But it is a luxury few people in war-torn Ukraine can afford.
Serhij says that he charges 1,790 dollars, corresponding to roughly 18,000 Swedish kronor, for a single bunker.
- So far I haven't sold very many, but that's just the beginning.
Serhij defends the price by saying that he has high material and labor costs.
What do you say to those who might think you're just trying to make money off the war?
- I have already received such comments from some "light heads".
But I only make a very small profit from this and that profit goes towards developing my business.