To buy a house in Canada u have to prove the bank if u r getting mortgage on house that this money transfer from UK from your account through legal ways into Canadian bank,
FOR MORTGAGE on house banks will ask u all bank transaction receipts plus both account information, also the money u bringing u claiming if it's your money, they want letter from that bank too might be, for how long that money was in that UK bank etc.
Keep all receipts and tax papers from UK they might also ask for it. If u want mortgage on house in Canada. All this because of money laundering act in force in Canada, it called in legal language FIntrack. They want to make sure that this money is not from fraud or from. Illegal earned etc. My recommendation is to transfer through Govt. Bank to any Canadian bank, u might get less exchange rate but it's better. GOOD LUCK.