better consult w/professionals - both architects & container building pros.

You would be better off to just do a proper addition . By the time you get the container in the right size and have all the work done to make it look like what you pictured plus get the interior up to code you will not have saved much, not to mention it might not even be allowed where you are.

there was a wonderful episode of Grand Designs that built a house from shipping containers. it was cost effective to do the whole house that way, but i'm guessing the necessary engineering wouldnt work out so well for just an addition. Well worth looking up if you are a Netflix subscriber or you might find the whole episode online somewhere.

There was no mention of cost saving in that episode in the EU this is a fairly common thing to do but in NA there are so many rules that it really is not cost effective

Better go somewhere they don't have any zoning! In areas heavily regulated like mine, and just about any other desired area, you will likely find "tiny" houses, "shipping container" houses, "recycled tire houses", etc. are a NO go period.

People assume they can built what they want, or that builders give them what the builder wants to build. In actuality, you generally get what has been mandated that you can have determined through local governments. The builder's limited options reside in building whatever pencils out within these parameters.

Just spoke with a friend in construction who finally got approvals after 1 1/2 years dealing with the city to be able to use hand milled lumbar from trees that were harvested specifically for a small accessory structure on his property. Since the wood didn't come from a lumbar manufacturer, it required an engineer to sign off on, numerous paperwork and approvals, etc. etc. etc. Only someone in the business, with the knowledge and $ to navigate the web of municipal rules/regs., would have preserved long enough to even accomplish it.

While you are considering options, you can get a quote for tempered glass in the estimated sizes you want, say, four pieces with size 4 feet by 8 feet, or 3 by 5, etc. Check with city hall to see if dual panes are required in your area.

Your photo is not of container construction. Rather, it's steel framed and masonry construction, with tempered or laminated glazing. Said differently, $$$$...

Have you looked at dwell's website? Many articles and examples there. Here is just one page ...

https://www.dwell.com/query/shipping%20container

A Rustic Shipping Container Home Built on a Budget

https://www.dwell.com/photo/6133573221695094784