What material will be above a large opening

[john2k]

I live in a new-build and on the ground-floor the end of the property is completely open leading to an open extension making the floor space downstairs much bigger. The extension has glass roof making it look like a conservatory but it has brickwork all around. I've attached a few pics. The roof of the extension leans on the back of the house that is open and a good amount of the back of the house is inside the room and plastered. I want to mount something on that wall but wanted to know what kind of material will be behind there?

I am assuming there must be some sort of RSJ going right across to hold up the first floor. So I dont want to end up drilling into an RSJ. So question is will the RSJ be right at the bottom and assuming I go up certain amount will I miss the RSJ? Also, when you look at the back of the house from after the roof it's all brickwork, but the bit inside the room is all plastered so not sure if behind the plastering is bricks or not.

Any suggestions would be great. Thanks

In the pic below towards the top left you can see a bit of the plastered section I am referring to. This goes and touches the inside of the sloped roof and from the other side it's brickwork.

 

[tomfe]

Yes there will be some form of steel work above the opening.
You might be lucky and they clad the beam with wood but as it looks like a new build apartment I doubt it.

What are you wanting to hang?

 

[john2k]

Yes there will be some form of steel work above the opening.
You might be lucky and they clad the beam with wood but as it looks like a new build apartment I doubt it.

What are you wanting to hang?

An indoor part of a split air-con system. From the bottom how high would the steel work go before bricks are support on it for the top floor?

 

[tomfe]

I would imagine you'd be safe 300mm up.
But you can just try a drilling a hole and see what it hits.