I’m a builder and my wife is a realtor. My wife and I would like to buy a housewarming gift for a couple we’ve built a home for. I know tastes vary but would there be a special something we can do for them?
Thanks for the help.
Buy a fish tank and have them put it in their front window. It is supposed to bring money into the home.
Traditionally when Taiwanese move into a new house they want everything new. That means they will have to buy a lot of new appliances. Traditionally, when someone moved into a new house, they would have a banquet party and you would bring them money in a red envelope. These days people ask what new appliances you need and they would buy you some new appliance, refrigerator, washing machine, or something cheaper like a microwave, blender, toaster. Remember, they would like to replace everything with something new, even if they have it already.
You could also get them a picture for their wall or a mirror. Mirror might be better than a picture, lest you scare them with a picture that has a face in it. Faces in pictures sometimes give Taiwan people the creeps.
You might consider buying them a set of antique wooden windows or Japanese-era vases. The windows are relatively inexpensive - starting at about NT$6000 for a small less detailed pair. As for the pottery, I think the old beige hong lu jiu vessels (traditional wine bottles) give a room a nice rustic feel for a little more than a thousand each. Of course, you could always ignore my advice and buy them a rice cooker! 
I always send a bottle of wine or XO as a house warming gift, if I know the family drinks alcohol.
If they don’t drink I try to look something pretty and useless. Like a crystal art piece or a painting.
Is the family in the USA or Taiwan?
It’s a US family.
Thanks for all the suggestions -
shane