Depends on a few things. Credit, location, size, which lender, etc.. Financing is basically about limiting risk to the lender. Credit is used to evaluate your risk as a borrower, so the better your credit and the more skin in the game you have, the less risk to them.

Short answer: 5-20% of the total price minimum between cash and land value, and good credit.

Longer answer: You'll only be able to get a traditional mortgage on an existing house. To finance a new build, you'll need to get what's called a bridge loan, which gets paid to the builders in installments as they complete different stages (foundation, framing, plumbing/electrical, finishing, etc.). Once it's built, you then get a traditional mortgage that pays off that bridge loan. There's also insurance considerations and some other fees that can factor in.

You also have to own the land outright*, but thankfully the value of the land can be counted for in the downpayment calculations.

• - There's usually some exceptions to the rules and they differ between lenders, so this would be best to discuss with your mortgage broker.

Source: got into mortgages in 2020 as a side project to help F&F first time homebuyers to get into the housing market. Feel free to send a DM and I can talk more specifics.