Total Rehab Time For a 900sqft House

[Adam Oldham]

I was curious if there is any general consensus on how long a 900 sqft single story ranch should take to completely rehab. In my mind I have always budgeted 2-3 months but this time and time again seems to be overzealous and tends to be much longer. I have done several flips but all of them tend to take longer than I expect. I am not sure if it is a contractor issue or just that projects like this take this long. 

To give more details about the house it was a full renovation, we had the house gutted all way down to the studs on interior/exterior, at one point you could see through the house. We opened up the living room/kitchen with headers, installed a new roof, siding, flooring, trim, doors, tile shower and floors, paint, installed new subfloor etc. 

With these details in mind how long would you budget to complete a renovation project of this size? Additionally our bid to complete this project was approximately 85-90k for the full renovation and we provided a large portion of the materials(e.g. framing, siding, roofing, finished fixtures etc). Knowing this do you think the rehab cost was reasonable?