I would imagine the drawdown date of 1st December was in effect how long your original mortgage offer from NIB was. I can understand you not wanting to pay mortgage & rent together but in effect every payment you make you are getting closer to owing your own home so it's not a real disaster. If you have agreed a fixed rate mortgage be aware that if you do not drawdown within the terms of the agreed loan you may leave yourself open to an increase in your interest rates if your contract with NIB was prior to the last number of interest rate rises, that itself could add quiet an increase to your monthly payments (major money over the lenght of your mortgage)!