lightweight large pattern (non-hatches)

Hello everyone,

As a landscape architect, I've to work with large site and repetitive pattern i.e pavers. As I've to create always my own pavers pattern most of the time, this mean there is no "hatch patterns" that works for me. So, when I've big surface to complete with my repetitive pattern, the file is getting huge and laggy (and it is normal with so many polylines). 

I wonder if there are solutions to lightweight these kind of operation. Like, to group, or merge, or anything that could actually reduce the size of the file.

Best regards,

David

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