When insulating a new house does the poly have to be caulked and taped at the top?
Unless you live in Canada, Alaska, or a similarly cold and moist climate, you neither need nor want interior poly, especially if the climate is rainy, if the house will ever be air conditioned, if you are using OSB or fiberboard (e.g. Celotex) sheathing, if you're applying stucco or adhered brick or stone right over the sheathing with no rainscreen gap, and ESPECIALLY if all of those are true. Just Say No.

For more info on this subject, see the following:

http://www.greenbuildingadvisor.com/blogs/dept/musings/when-sunshine-drives-moisture-walls

http://www.buildingscience.com/documents/reports/rr-0104-solar-driven-moisture-in-brick-veneer

http://www.greenbuildingadvisor.com/blogs/dept/musings/do-i-need-vapor-retarder

http://www.greenbuildingadvisor.com/blogs/dept/musings/vapor-retarders-and-vapor-barriers