On the long term a simple structure with 1 simple gable roof (no dormers) will have less chances of roof leakage, leading to less rot issues, interior water damage, etc...

However, there were no sign of leakage anywhere.

The reason you want an entity is to put the property into a box that's sealed all around, with no leakage to your other assets.  

TI on the inside is generally about 35 a foot for new builds.So it might look something like this.National tenants 3-top:Land: Own it zero costConstruction Exterior: 125 a foot X 10,000 foot = 1,250,000Construction Interior: 35 a foot X 10,0000 ( Starbucks can be 50 a foot sometimes) = 350,000Rents say conservatively 25 a foot national tenants X 10,000 = 250,000 NOIThere will be base rent plus cam reimbursements and then backing down of some cap on cam with leakage and market vacancy. 

The bottom floor of the duplex has been completely gutted due to prior leakage from the top floor.  

If it is a tract home chances that copper plumbing are contractor quality and it can be pierced by a gravel, rock or a nail causing water leakage.

As far as install goes, it's not particularly difficult but improper installation can cause issues with moisture and air conditioning leakage. 

Sometimes in CCR's they will have tenant lease language that pushes lots of costs onto that particular parcel owner ( example maintaining a detention pond) and if your tenant has some caps then the landlord can be eating that cost ( CAM leakage ) which can reduce expected NOI.

(4 bedroom cape, interior redone) The furnace most likely froze, as it was not winterized properly and there's some plumbing leakage.

Some water leakage happened and black mold appeared.