Most of the times it is noticed that the married couple would be busy with their targets in the work location and would be very tired by the time they come back home. Also, it is very important for them to survive in their jobs and hence would be busy all the times. On top of all this struggle if they have to buy a new home for their living, then it would be even more hectic. So, if you think you could afford constructing a house for them then do check the designs of the duplex homes that would best fit for their stay. Since, you are done with your life and should be supporting your children it is good enough you plan for a small duplex house in which the newly married couple could start their life.
Of course, you should give them an option of even selling it when they are in need of some funds. Well, if they consult you on what is required by them then it is well and good. Though they do not consult you, it should not be a concern as you are gifting them the house and once gifted it is their property and they could do anything with it. But, if you want them not to sell it for any of their needs, then you should make this property as the outstanding property of rest all that you own. This is possible only when you consult the experts who have done excellent designing of the house that they have constructed so far.
While most of the designs look attractive and impressive, it is very rarely that the building would look outstanding after having completed the construction. Hence, it is quite important that you rely on those experts who would never deviate from the design they do for your building and still confine to the budget that is first agreed up on by both of you.