As a first time home buyer, you may not be aware of all the costs in buying a home.  This makes determining how much of a mortgage you can afford difficult.

Qualifying ratios
Generally, lenders will use a 32/42% Gross Debt Service (GDS)/Total Debt Service (TDS) ratio.  This means that 32% of your GROSS income (before taxes) can go to your housing costs, which include: mortgage payments, property taxes, strata fees (if applicable) and heating costs.  42% of your gross income can go towards your housing costs plus your other monthly debt payments.

What else you should consider 

Strata fees
When you are shopping for prospective properties, make sure to pay attention to the strata fee, as these can be up to $400-$500 a month in some developments.

Other debts
Lenders have specific formulas when calculating minimum payments on loans and lines of credit.  Be prepared for the possibility that you may have to pay down some debt or re-organize it.  Your mortgage broker can assist you here, especially since they have so many lender connections.

Credit Checks
Your mortgage broker will do your credit check.  Make sure you get this done early in the pre-approval process, just in case there are issues you may have to address.  If your credit score I unexpectedly low, you will need time to get it to the minimum level where a lender will consider it.

Budget
While your mortgage broker will tell you what you qualify for, every person has different expenses.  Review your bank statements for the last 3 months and determine how much you can realistically pay for housing costs.  If you live at home and don’t pay rent, each month put aside what you think you would pay in housing costs and see if that amount is sustainable with your lifestyle.