David Hamilton and his fiancee Lyna Pen are in their 20s but hope to be mortgage-free within 10 years.
The Auckland couple bought their first home two years ago in Te Atatu for $432,000 after scraping together a 10 per cent deposit.
They took a 30-year mortgage but have been chipping away at the principal ever since.
Mr Hamilton, 28, is an electrical company engineer and Miss Pen, 25, is a pharmacist.
The couple earn nearly $130,000 combined. With no children, they have been able to put money aside since buying their house and have made several $10,000 lump-sum payments against the principal.