Granny Flat Loan Calculator

Why Use Lime Mortgage Brokers' Granny Flat Loan Calculator

Discover Your Usable Equity: Find out how much equity you may be able to unlock from your existing home to help finance your granny flat project. Our calculator estimates your available equity based on your property’s value, current mortgage balance, and your lender’s maximum Loan-to-Value Ratio (LVR).
Plan Your Granny Flat Build with Confidence: Whether you’re building for family, creating additional rental income, or increasing your property’s value, understanding your available equity helps you make informed decisions before starting your project.
No Need to Refinance Your Entire Home Loan: This calculator is designed to estimate whether you could access equity without refinancing your entire mortgage. It’s a simple way to explore your options before speaking with a broker.
Quick, Accurate Estimates: Simply enter your property value, mortgage balance, estimated granny flat construction cost, interest rate, and loan term. In seconds, you’ll receive an estimate of your usable equity and potential borrowing capacity.
Understand Your Financing Options: See whether your available equity could cover the cost of your granny flat or if you may need additional financing. This gives you a clearer picture before approaching lenders.
Expert Advice When You’re Ready: Every homeowner’s situation is unique. Once you’ve calculated your estimated usable equity, our experienced mortgage brokers can explain your options, compare lenders, and help you choose the right finance solution.

How It Works:

Enter Your Property Details: Input your current property value and outstanding mortgage balance.
Add Your Granny Flat Project Costs: Enter your estimated granny flat construction cost along with the interest rate, loan term, and your lender’s maximum LVR.
Calculate Your Usable Equity: Our calculator estimates how much equity may be available to access based on your home’s value and existing mortgage.
Review Your Results: See whether your available equity may be enough to fund your granny flat project and gain a better understanding of your financing options.
Talk to a Mortgage Broker: Our team can verify your borrowing capacity, explain your results, and help you secure the right loan for your granny flat build.

Ready to Unlock Your Home Equity?

Take the first step towards financing your granny flat with confidence. Use Lime Mortgage Brokers’ Granny Flat Loan Calculator to estimate your usable equity and explore your borrowing potential. When you’re ready, our experienced mortgage brokers are here to help you turn your plans into reality with finance solutions tailored to your goals.

Property & Loan Details

Enter your current property and mortgage information

Current Property Value

Current Mortgage Balance

Granny Flat Build Cost

Interest Rate (p.a.)

6.25%

Loan Term (years)

30 yrs

Max LVR Lender Allows

80%

Accessible Equity
—
Available to draw

New Loan Total

—

After top-up

New LVR

—

Post-build

Monthly Repayment

—

Principal & interest

Total Interest

—

Over loan term

Existing Equity

—

Before build

Annual Repayment Breakdown

Year	Opening Balance	Principal Paid	Interest Paid	Closing Balance

Important: This calculator provides estimates for illustrative purposes only and does not constitute financial advice. Results assume principal & interest repayments, no fees or LMI, and a static interest rate over the full loan term. Usable equity is calculated as (Property Value × Max LVR) − Current Mortgage Balance. Actual borrowing capacity depends on your income, expenses, credit history, and lender criteria. Always consult a licensed mortgage broker or financial adviser before making borrowing decisions.

Apply for the finance that you need

Lime Mortgage Broker Reviews

      EXCELLENT  
   Based on 67 reviews 
    
 
 
 
   
 
 
       Posted on Google  
   
   Anabelle Williams 
 
 
 
 Trustindex verifies that the original source of the review is Google. Can’t thank Shawn and his team enough for helping us with our first mortgage 4 years ago and refinancing just recently! We really appreciate that he goes above and beyond to assist and his quick service turnaround time.  He is always so helpful and friendly when answering my many questions. He applies his strong expertise in a professional and effective way for you to understand. Can’t recommend him enough..Best in the biz!
  
 
      Posted on Google  
   
   Carmela Verzini 
 
 
 
 Trustindex verifies that the original source of the review is Google. Our experience with Lime Mortgage brokers has been absolutely fantastic, they have been so helpful with their assistance, advice and support. Thankyou Shawn for all your time, phone calls and always making sure that we receive the best opportunity to accomodate our needs, Lydia has also been so amazing with all the updates and explaining situations when we were unsure about something. I will always highly recommend Lime Mortgage Brokers to anyone in need, because we know that we can always rely on wonderful and caring support and advice. Thankyou Shawn, Thankyou Lydia, Best Wishes always Enzo and Carmela Verzini
  
 
      Posted on Google  
   
   Dean Innes 
 
 
 
 Trustindex verifies that the original source of the review is Google. Shawn was amazing when helping me find finance for my property. This was my first time dealing with banks and Shawn was always available to help. The team at Lime Mortgage Brokers were attentative, efficient and proffesional. Couldn't ask for much more! Highly recommend.
  
 
      Posted on Google  
   
   Ella Schooling 
 
 
 
 Trustindex verifies that the original source of the review is Google. Made the impossible ' possible for me and my family . Amazing team and so easy to deal with .  Thankyou shawn
  
 
      Posted on Google  
   
   andrew ward 
 
 
 
 Trustindex verifies that the original source of the review is Google. Shawn and Lydia from Lime Mortgage Brokers made the whole process easy from start to finish. They were proactive, knowledgeable, and really took the time to understand what we needed. Communication was excellent, and we felt supported every step of the way. We’re extremely happy with the outcome and wouldn’t hesitate to use them again or recommend them to others. Thanks again Andrew & Talie
  
 
      Posted on Google  
   
   Savanna Oats 
 
 
 
 Trustindex verifies that the original source of the review is Google. Excellent service, quick to respond and Shawn and Lydia are very genuine -  I felt that they had my best interests in mind when helping me refinance.
  
 
      Posted on Google  
   
   sean kirsten 
 
 
 
 Trustindex verifies that the original source of the review is Google. Shaun was very easy to deal with answered all questions and couldn’t be happier with the results highly recommend.
  
 
      Posted on Google  
   
   Isabelle Wheeler 
 
 
 
 Trustindex verifies that the original source of the review is Google. Lydia and Shawn were very helpful and approachable throughout the process of us refinancing. We were very happy with their service and would recommend their services to anyone seeking assistance in this financial field. Thanks Lydia and Shawn!
  
 
      Posted on Google  
   
   MG 
 
 
 
 Trustindex verifies that the original source of the review is Google. If you're looking for a mortgage broker in Perth, then I would strongly recommend Lime - Shawn and team go above and beyond the usual service to find an optimal solution.
  
 
      Posted on Google  
   
   Amy Collins 
 
 
 
 Trustindex verifies that the original source of the review is Google. I've been using Shawn for 15 years during my multiple house moving! Very patient, helpful and knowledgeable to ensure we find the best outcome. Highly recommend him!

Earn as much as $250 in vouchers of your choice when you refer a friend to Lime Mortgage Brokers