It is an FHA loan best tier rates on the One-time close construction program are currently right around 4.25% for a 30 year fixed. This is higher then a purchase or refinance rate in a FHA loan by a decent amount but there is a lot more risk and a whole lot more moving costs on this type of loan than a purchase/refinance loan.
Just a any FHA loans the PMI is .60 a month and is on the loan for the life of the loan along with the 1.75 upfront that can be financed. BUT, you can always refinance if it makes sense at the time once you get the loan to value where a conventional loan would not require mortgage insurance.
This program, along with the VA program that allows for 0% down, are great for a segment of the population because it allows them to be able to get a custom construction loan with less then 10% or more down which most construction programs require. It will also allow for lower credit scores then most One-time close construction programs will allow as most bank portfolio products require very strong borrowers. It also important to note the the FHA/VA programs are 30 year fixed programs where most bank portfolio products are ARM's which is just fine for a lot of borrowers and makes sense, but some borrowers do like the security of the 30 year fixed.
It is not the place for a borrower with 780 credit score and 20% to put down. We put those borrowers into a different construction program or refer them to a referral partner that has a great program for them. But, it certainly allows a lot more folks to finance their custom construction which is great.