Rent Splitting Question

[Keilan Clark]

I am about to rent out one of my houses which happens to have a guest house on the property. The future tenant has requested to sign two different lease agreements, one for the guest house, and the other for the main house. Splitting the total rent by half for each, so he is able to write off the guest house to his business.  

Is this legal or any tax implications on my end? I live in Canada but can't seem to find anything on this. 

Any help would be greatly appreciated.