I have been a licensed General Building contractor for many years as well as being an architectural designer.

BP always blocks my comments if I give out my website in the forum since it goes to my architecture site.

These typically run 20-25% of hard costs and include costs such as engineering, architecture and debt service.

However, like @Brian Ploszay noted, knowing which walls are structural and which are not may require an architectural analysis, architects engineers or competent contractors should be able to provide this for a decent price. 

I've got line items broken out very well, for example -"Frame house per architectural plans $xx,xxx""Drywall interior $xx,xxx""Plumb in 17 new fixtures $xx,xxx""Portapotty for 6 months $xx,xxx"What doesn't need to be on the scope of work is that we're using 850ea 2x4x8 studs, 10 boxes of nails, 52ea 90 degree pipe fittings, etc... that level of detail is too distracting, byzantine, and just not helpful.  

.) $150,0003) Roof Deck (300sf @50sf) $15,000Site ImprovementsHardscape $25,000Landscape $35,000Total Construction Costs $972,000Pre-Construction Costs Architectural Fees (10% excl landscape) $93,700Structural Engineering $12,500Title 24 $500Reimbursable Expenses $1,500Local Permits and Fees $15,000Total Soft Costs $125,700Total Estimated Project $1.1m

Tear off, fix rotten sheathing (maybe extra cost), install architectural shingles.

With a background in architecture, urban planning & design, I have always been personally invested in neighborhoods and development, but have never purchased a property.

I recently finished college, I majored in architecture.

Do you have any architectural plans and engineering that have been done on the building yet?