To obtain CMHC Mortgage Loan Insurance, mortgage brokers pay an insurance premium. Typically, your broker (lender) will pass these costs on to you the borrower. Your broker (lender) will give you the exact price when you apply for a mortgage.
The CMHC Mortgage Loan Insurance premium is calculated as a percentage of the mortgage loan and is based on the amount of your down payment. The higher the percentage of the total house price/value that you borrow, the higher percentage you will pay in insurance premiums.
Remember: if you choose to avoid the insurance premium, you will typically pay much higher interest rates and additional administrative fees. Which means, for the vast majority of borrowers, the cost of CMHC Mortgage Loan Insurance is more than fully offset by the savings achieved.
A 10% premium refund and extended amortization period without surcharge may be available when CMHC Mortgage Loan Insurance is used to finance an Energy-Efficient Homes.

Information obtained from the CMHC website