Ottawa Real Estate Investors Organization

Question: For the intermediate landlord/property investor--how does one go from an "intermediate" property owner- say 10-20 doors to a more senior level? I've been refinancing my existing properties to secure a down payment on a new property but I find I can only do a purchase every 18 to 24 months at that rate. Some of the recent presenters seem to be purchasing every 3-5 months. How do they get their down payments?