Yep, new plumbing, new wiring, modern kitchen ... but original footprint, wood siding and hardwoods — Give and take with the new and old. 

First is environmental, condition and ownership of the pumps, canopy and any other equipment.

Very helpfulRe: 15% it can be a good rule of thumb, but understand that every project may break that rule due to specific issues (title, environmental, local government, design, etc.) but yes your permits, arch, legal shouldn't be blowing up your budget at 25% off the bat.

They will let you know exactly what is needed to do.Where I live, adding a bedroom is not hard to get approval for, since you aren't really adding sq ft to the footprint of the property. 

You could make an offer with a due diligence period to give you a chance to get inspections, and check for any environmental issues (cars leaking fuel, oil, etc... could be an issue). 

I have the first 2 years free(dad works there) and planning to major in environmental science.

In short, you should focus on major electrical, plumbing, foundational, structural, or environmental factors only if you want your best bet of negotiating down the price.

Any objections based on the economic environmental or the individuals portfolio makeup or risk tolerance I tell them I’m not a financial planner, financial advisor, or wealth manager,; I’m a real estate specialist.

There is lots of environmentally concerned buyers.

With industrial or properties involving hazardous materials (gas stations, medical offices) is the risk of environmental contamination usually covered by insurance (which the tenant would be paying for)?