Own a 1.5 acre lot and 24k industrial building - devel. advice!

[Rob Stiefel]

My family and I own a 1.5 acre vacant lot - it has a high voltage wire setback requirement - but front of the lot is .7 acres of buildable space + parking can infringe on the powerline setback. Across a minor road, sits a 24k industrial building that is built on entire lot (grandfathered). Both sit on a major industrial highway ~16k cars per day & 18k living within 3 miles. 

Can anyone share a proforma to model NPV of just selling the vacant lot to a nationwide car wash ($1.5-$2M) - vs construction costs to build out for a QSR or something similar ? 

For the industrial building, we may tear down part of building and search for a medical office use or pharmacy chain, etc. 

My experience is in single family, so just looking for a little guidance! I am a young investor. 

Thanks !!