Anyone with experience with lot severance?

Hi RFDers,

I'm looking at purchasing a house on a 50x120 lot with the idea of severing and building two houses on it in the future. I know that getting permission to perform the severance from the city is one of the main things (the housing zone currently has a minimum frontage fo 50ft, still trying to work that out) but are there any other gotcha's that I need to look out for? Does anyone know how the capital gains tax will work in that scenario?

Any help is appreciated. Thanks

BTW I'm in Toronto