Hello. My family and I are contemplating returning to live in the UK after living in BC for 10 years. We own a house here and obviously plan to sell up when we leave, pay off the remaining mortgage and hopefully be left with a good profit. While living here we also built a house in our hometown in uk and have it rented for now with the intention of moving into it when we return. My question is would the sale proceeds of our canada house be subject to capital gains tax. Although we own two properties they are in different countries and our house in canada is our only home here? It's all very confusing. Any help would be much appreciated thanks.

Your BC house normally counts as your principal residence for the time that you live in it. There will be no capital gains tax to pay on it. If possible, try to sell it before you leave Canada otherwise the paperwork gets complicated and the buyer will have to withhold a fair chunck for the sale price until the paperwork formalities are completed.

When you leave Canada any excess of the fair market value of your UK house over the cost to build it will be subject to capital gains tax in Canada.