I have to respectfully disagree with @Frank S. on the nature of Bigger Pockets.

It shows a personal nature to your interaction and your dreams and thoughts instead of a robotic developer that wants him to do something for them.No legal advice given.

The owner stated he is out of town due to the nature of his job, but house does have lockbox. 

Many text messages I receive for work may be of the urgent nature - simply ignoring them is not an option. 

I've been doing infill lot's in PG county Marland and the process I can tell you differs from county to county but I'll give you an outline of my process 1) It's not unusual to see lot's on the MLS for 100+ days, do not be alarmed there are not too many people operating in the sphere 2) Just like rehabs I typically start by looking at what I can potentially build on the lot and my ARV  ( I know my area pretty well, so I'm only buying lot's in specific zipcodes ) my typical target is 2500sqft above grade with an AVR for $500+ 3) My research starts with my surveyor, I provide him with the address, he comes back to give me thumb-up or down or any potential problems I may face, such as wetland, DDO zone  (Development District Overlay) e.t.c 4) After closing on the lot in my county I need to get NRI ( Natural Resource inventory) this plan provides documentation of the existing conditions on a site / TCP ( Tree Conservation Plan ) exemption, I get an exemption because I'm buying infill lot, this is typically handled by my surveyor and take about 30days 5) Next is my stormwater management: Again I'm getting an exemption because I'm disturbing less than 500sqft of land, handled by my surveyor 6) Once I have the 2 approvals listed above, I'm allowed to submit my building plans for approval, in my county turn around time for approval is about 3-4months Hope this helpsbelow is a link to my last new construction project, got a few more in the pipelinehttps://www.redfin.com/MD/Cheverly/2417-Parkway-20785/home/10547525

That's the nature of distressed properties such as forclosures, estate sales, etc. 

Network and they will naturally come your way.

And the illegal nature means no bank lending so few buyers. 

As long as YOU don't live in it, you should be good.A rebuild letter is a zoning verification letter that states that your subject property can be restored to its original condition and use in the event the property is destroyed by fire or any other form of natural disaster.   

In fact, if the communications are unsolicited, repeated, and commercial in nature (as you are running a business) you are at risk of being sued for TCPA violations, where the "sellers" you are harassing can bring private party action against you for between 500-1500 per incident.