My dad is a UK citizen and owns the house i live in in the US, if I am added to the deed to reduce the cost of h/o's insurance, what are the gift tax consequences?

[Carl]

Zero. There is no such thing as an actual "gift tax" that is imposed. The name of that IRS Form 709 -Gift Tax Return is misleading in that since. The 709 needs to be filed ONLY if the gift given in a tax year is more than $15K. The giver of the gift files it. It's informational only to the IRS. The recipient of the gift doesn't report anything to anyone.  However, the rules are a bit different where a foreign national is involved.

Receiving gifts from foreign citizens
Gift taxes only apply to the person making the gift, not the person receiving it. Foreign citizens generally don't have liability for U.S. gift tax and therefore don't need to report gifts for those purposes.

However, separate IRS regulations require recipients to report a foreign cash gift. IRS Form 3520 is required if you receive more than $100,000 from a nonresident alien or a foreign estate. In addition, gifts from foreign corporations or partnerships are subject to a lower threshold that is adjusted for inflation each year. For 2016, gifts of more than $15,671 trigger the filing requirement.

You won't owe any tax as a result of filing these documents. However, failing to file them can result in IRS penalties.

The gift tax isn't something that most Americans ever have to deal with. But if you make or receive a foreign cash gift, you'll need to keep the gift tax in mind and make sure you follow all the rules that govern this type of gift.

[jtax]

You should seek the advice of an estate planning attorney familiar with federal AND your state's laws. Both are important.

This is a very complicated area. I am not sure what @Carl suggests is correct.  This article says that non-resident non-citizens owning property in the US have only a $60k federal estate tax exemption.

https://mfin.com/m-intelligence-details/nonresident-alien-tax-trap-the-60k-estate-tax-exemption

in addition if you live in one of the six states that have an inheritance tax you (not your dad as the giver) may be subject to a state tax. (There may be exceptions for gifts from parents or gifts below a certain amount.)

https://taxfoundation.org/does-your-state-have-estate-or-inheritance-tax/

Note that in general inheritances (gifts given at death) and lifetime gifts are treated almost the same. Otherwise rich people could avoid estate taxes by giving away everything the day before they died. Most of the estate tax (federal and state) solve that by taxing lifetime gifts the same as gifts from a descendant.

Once again, this is too complicate to rely on advice from the internet. Please seek the advice from an estate planning attorney. 

[Carl]

Another thing to keep in mind too, is how your state deals with this. All we've covered thus far is the federal side. With 37 states that tax personal income, not all of them treat this situation the same way.  All the more reason to seek personalized professional help.