Has anyone renovated an early 1990s commercial building ?

[Malynda Sala]

I just looked at a 6000 sf commercial building, built in 1990, on a small town Main St

The 1st floor is a store, then on the 2nd and 3rd floor are three apartments with space for a 4th

The building is gorgeous but in original condition, It defiantly needs a new heating system and some plumbing work, The electric was on but I'm assuming that needs updating as well

I'm planing on having some estimates and an inspection but fear the renovation would be to costly for the project to be viable, it would probably cost more to renovate than the asking price 

If I bought it, I'd use the 1st floor for my established business, rent at least 2 apartments and live the other 

My main concern in plumbing and heating, Has anyone done an oil to gas conversion in a building like this? If so, what was the ballpark price? What's the cost difference adding separate heat compared to one zone for the whole building, gas is at the curb

What are the other issues I should look out? 

Has anyone completed a project like this?  I'd love to see your posts or hear your thoughts about it, it's an amazing building but sadly, it may need too much work for me

Thanks!