Building a property portfolio through refinancing can be a viable strategy to leverage your existing properties to acquire new ones. Here's a step-by-step guide on how to do it:

1. Assess your current properties: Start by evaluating your existing properties in the portfolio. Look for properties that have appreciated in value and have built up equity over time. Equity is the difference between the property's market value and the remaining mortgage balance.
2. Conduct a property valuation: Get an updated property valuation for each of your properties. This will help you determine the current market value and the amount of equity you have in each property.
3. Review your financial goals: Revisit your financial goals to ensure that building a property portfolio through refinancing aligns with your objectives. Determine how many new properties you want to acquire and the type of properties you're looking to invest in.
4. Speak to a mortgage broker or lender: Engage with a mortgage broker or lender to discuss your refinancing options. They will assess your financial situation, creditworthiness, and the equity available in your current properties to determine how much you can borrow.
5. Decide on the properties to refinance: Based on your goals and the lender's assessment, choose the properties that have enough equity to be refinanced and use the released funds as a down payment for new properties.
6. Research potential new properties: Look for properties that fit your investment criteria. Analyze their potential for rental income, appreciation, and overall profitability. Location, market trends, and property type are essential factors to consider.
7. Calculate costs and expenses: Consider all the costs associated with refinancing, such as closing costs, loan origination fees, and any potential prepayment penalties on your existing mortgages. Additionally, factor in the expenses related to purchasing and managing the new properties.
8. Apply for refinancing and new mortgages: Once you've identified the properties you want to refinance and the new properties you want to purchase, apply for the refinancing and new mortgages. Work closely with your mortgage broker or lender to complete the necessary paperwork and meet all requirements.
9. Complete the refinancing process: After approval, complete the refinancing process for your existing properties. The lender will pay off the existing mortgage, and you'll receive the funds representing the released equity.
10. Acquire new properties: With the funds from the refinanced properties, use them as a down payment to purchase the new properties.
11. Manage your portfolio: Once you've acquired new properties, continue to manage your portfolio effectively. Ensure you have a solid property management plan in place to maximize rental income and property value.
12. Monitor and review regularly: Regularly review the performance of your portfolio and make adjustments as necessary. Stay informed about the real estate market, economic trends, and changes in rental demand.

Remember that refinancing involves taking on additional debt, so it's crucial to carefully assess your financial capabilities and risk tolerance. Additionally, seek advice from real estate professionals to ensure that refinancing aligns with your long-term investment strategy.