Why do you think owning a house is very important? Yes, there are several reasons why one would love to have an own house. The first is to get rid of the conditions that are forced by the house owners on the tenants. Though you pay huge rents it is obvious that you are not allowed to customize the house according to you basic needs. Though you do not do major changes and are willing to stay in the rented house for a very long time, there are always restrictions that you should abide by for living in the rented house. This sort of inconvenience would always trigger the thought of owning a house.
But, this inconvenience should not make you desperate to own a house of any type. Plan for the duplex homes which you think would be most appealing even after a decade and could help you be proud for owning such a house. Well, the loan would take a similar amount of time to be cleared and hence choosing a builder who would design the house for future compatibility is more important. Also, by looking at your house design, the banks would sanction the loan amount, the better design the higher the loan amount.
Since you would get the support from the banks you could also choose the best design that to compromise on certain aspects and thereby repent at a later stage that you could have taken that extra mile to own a lovely house than to compromise on certain aspects of the construction. When you own a duplex house you hardly have to rely on your children in your old age. So, for anyone it would be a life time achievement to have an own house and it would be good if that house to stay in is a duplex house.