Can i fit my A1 designated durgo below the flood level?

[djcater]

I have recently had a single storey rear extension built. I have out in a downstairs toilet and sink. Mu main upstairs bathroom is vented through the roof. I want to use a durgo on the downstairs toiletand i bought a floplast af110. When i read the instructions it says it is A1 designated and can be fitted below flood level. Is this true? Will BCO accept this? What height can i fit this as it is big and ugly and i am not in a situation that i can box it in as my soil pipe is under the window and extending this will make it show in front of the window. does the pipe have to be dead vertivcal to the soil pipe? or can i direct it along to the wall then up?