Raising Door Frames to a standard door height in a 1 bedroom house

[Kristy Buchanan]

Hello everyone, 

I don't know if this is the correct section to ask this question. Please let me know if I need to post it somewhere else. 

I recently had my property raised and the flooring re-done. Unfortunately the door frames within the property were all trimmed at different heights when they leveled the floor. Does anyone know how much it would be (roughly) to widen and heighten 4 door frames and widen to a standard door frame? 

I have tall tenants that have to duck to get into 4 different rooms. 

I need a rough estimate of what the fix would be to speak with the contractor about what they are trying to charge me for their poor quality of work.