Loft Project

I'm looking to build a loft in my daughter's bedroom. This loft will span wall-to-wall (~11.5 ft) and support a full-size bed and a small reading area. I'd like to build it without any visible support. Anyone have any suggestions? Eventually, I may mirror this loft on the other side of one wall for my son's room. Should I be installing 4x4 posts inside the end walls (one exterior and one interior)? I've attached a rough draft of the sketch.

saj41 Welcome to the forum, nice 3D sketch and thanks for sharing
Do you have photos, of the room, and inside the roof space that you can also share?
Cheers
Chris

Here's a pic of what I'm working with. My sons room is on the other side of the left wall, and like I said, I may eventually mirror the loft on his side. Basically running the loft above the window. Thanks for any advice!

Thanks for the reply
That is a structural change that may require Building approvals?
Do you have the original plans?
BTW, more info is required.ie
Roof Materials eg tiles/CB?,
Walls, eg, Brick/Stud Framing?
etc
Also, you will need to provide some photos from inside your daughters roof,etc,
Cheers

Structural change - perhaps, I'll be checking with the county to be sure.
Original plans - If you mean for the house, I do not have those.
Roof - Pretty much what you see there with composite shingle, no attic space
Walls - stud framing with wood siding

Sorry, but I'm not sure I know what you mean by "photos from inside your daughters roof, etc."

Thanks!

Where are you building?
Check with your local Councils Building department, they should have your Plan/Structural s
Is the Internal roof Structure a Truss Roof or Timber roof frame

Timber roof - central beam supporting the pitched beams you see in the pic.

Timber roof - central beam supporting the pitched beams you see in the pic.

This is a great idea, and a great use of space. You will need to consult an engineer to see how best to build the structure without any visible supports.