For the purchase of a primary residence, the typical down payment requirement would be 20% of the purchase price. Generally speaking, the conforming loan balance should not exceed $417,000. Rates and programs are similar for vacation and second homes, as long as they are not income generating or investment properties. A lot of other factors may come into play. That said, if the buyer has excellent credit, they may qualify for a lower down payment, as little as 5%, with PMI (private mortgage insurance).
There are specialty programs for primary residences that require less money down. FHA has a minimum down payment requirement of 3.5%, but carries and up front and monthly mortgage insurance. VA loans are eligble for 100% financing. USDA also has a 100% financing option. Both these programs have an up front funding fee at closing, but no monthly mortgage insurance.
As always, for your specific needs, please contact a mortgage professional to review your options.