I just want to clarify that my point on the repayments being interest-only during construction was intended to convey the fact that you will not be playing a flat percentage of your scheduled principal+interest repayment based on the percentage of the loan you have drawn (which is what I suspect the OP was thinking).
This will make it a little easier to juggle the rent+loan repayment issue as the build progresses - of course once you take the rent out of the picture after moving into your new home then the financial pressure will ease, it's just the bit towards the end of the build where things can get a little tight and only having interest-only repayments on the loan during construction makes it that little bit easier to get through.
eg.
We have drawn 90% of our loan so our "normal" repayments would be 90% of ~$2300, which equals ~$2070.
However as we are only on interest-only repayments (which is standard practice for a construction loan for what I can gather) our repayments are ~$1700. Paying a bit less on interest-only repayments will help ease the pressure a little and every little bit helps when you are paying $2.5-$3k per month in total on rent and your loan.