I think there is a danger if you are too submissive to the school.
I spend several years being sweet to dd's junior school: by the end of it, I realised that they were making her crawl up the stairs on her hands and knees to get to her maths lessons because they thought it too much effort to simply change the timetable so her set was the one taught in one of the downstairs rooms. When she was unable to carry on doing this, she got not maths lessons at all. They also refused to let her use the disabled toilet because they thought it would be better to keep it clean for visitors.
Basically, I had spent so much time being submissive and understanding that they thought that I would never challenge anything.
Of course the school is under no obligation to suddenly magic a new building from thin air. But what they are legally obliged to do is to "make reasonable adjustments", that is to be imaginative about the way they work around the problem.
If your dd cannot access this room is there some other way she could access at least part of the curriculum? Some of it is not practical, so she could do this in the school's inclusion room, or wherever else it made sense for her to work. Or is there some other tech subject she could take instead? They may not be able to do what you would most like, but they don't have the option of sending her home; that is definitely illegal.
I blew a fuse when I opened my dd's school report and found that her teacher thought that she might have done better in maths if she had been able to access the lessons. On investigation it transpired that she had spent a whole term's maths lessons sitting alone in a classroom with worksheets and no tuition- while in adjoining classrooms maths lessons were being given to the lower sets, but her top set was upstairs. In her case, reasonable adjustment could easily have been made by letting the sets switch classrooms.
If you google Disability Discrimination education supplement, you should come upon a handy file which gives examples of reasonable adjustment in an educational setting.