Hi and welcome to Just Answer!If your son will not may you back - that will be a gift from you to your son and his wife.
Gift is an income, but not a taxable income for the recipient. Please see IRS publication 525 page 34 left column for reference - http://www.irs.gov/pub/irs-pdf/p525.pdf
So - there is no tax liability for your son and his wife.
The donor (the person who makes a gift) - if he/she is US citizen or US resident - will need to file a gift tax return and might be liable for gift taxes.
The donor may be required to file a gift tax return if the value of the gift is above $13,000 per person per year. There will not be any gift taxes unless the lifetime limit of $5,000,000 is reached.Let me know if you need any help or clarification.
Do i need to do a gift tax return each year till the value of the home isw reached, the vaule is going to be about $180.000.00
You do need to file a gift tax return each year in which the value of the gift is above $13,000 per person per year. If $180.000 gift will be in one year - you need to file a gift tax return in this year.
If i need to file is that at the end of the year? will i have to pay gift tax.
There will not be any gift taxes unless the lifetime limit of $5,000,000 is reached.Here is the form - www.irs.gov/pub/irs-pdf/f709.pdfAccording to instructions - www.irs.gov/pub/irs-pdf/i709.pdf - see page 3the gift tax return is due by Apr 15 following year.