Changing a wall with diagonal bracing to allow a window to be installed

[lachlang]

I am building in a new area under my high set home and want to change a couple of walls so that there is a fair size window in each. Currently there is diagonal bracing between 75mm RHS posts which on the plans is giving 13.5kN of bracing. I have asked several people to design a panel that can be bolted to the columns which will give the same amount of bracing, unfortunately the structural engineer I asked to do the design got the plans and photos than wanted to reinforce the slab and remove other wall sheeting to move the bracing to a different wall. This all started to sound expensive so I asked for a prefabricated panel that could be bolted/welded in-between the columns which would give the same amount of bracing, thus no change to the houses structural design. He is since not returning my calls or emails.

I have a degree in electrical engineering so I understand the risks and principles but I do not think I need to go back to the whole design if the bracing between two posts is replaced like for like.

I am looking for a structural designer who can offer a design either in timber or steel for a wall panel approx 3000w x 2400h with a 1800x1200 window, window size can be reduced if required. The wall will be clad in 200mm weathertek and the inside sheeted in plaster board.

Any assistance or advice on this would be much appreciated and I am willing to pay for a signed off design.

Regards
Lachlan

[r3nov8or]

I think you need to engage another engineer/s and see what they say (without putting anything into their heads) and if they come up with the same/similar solution as the first guy, that's that.

[lachlang]

Thanks for your response, can I ask if you are basing your comment on a understanding of structural engineering or is your comment of a general nature. I do not understand the need to look at the structure of the slab when the bracing is currently correct between 2 posts as originally designed and the only changes is to the shape of the bracing between the 2 posts.

As an electrical designer if I was asked to size a new sub-main cable from copper to aluminium I do not need to redo a complete site calculation if the original design was correct, it would be a case of selecting a new aluminium cable that matched the capacity of the original copper cable.

Happy to have a structural engineer prove my theory wrong.

Regards
Lachlan

[r3nov8or]

My response was general in nature. I was simply suggesting you get a second opinion, or more, if need be.

[cherub65]

Problem is your not replacing "like for like" by removing the simple diagonal bracing, which I'm guessing goes from pretty much from top to bottom of the RSH? will mean a completely different approach.
Thus moving bracing to another wall is probably the easiest and cheapest option, what did he mean by slab reinforcement?
Hard for anyone here to offer any sort of advice let alone structural with out a plan or photos, as you can appreciate bracing is one of the most important building elements in a structure such as yours.