Try to avoid what pro carpenters call a "growing pattern syndrome." This can occur when you are cutting a number of studs or other pieces to length, then always use the most recently cut piece to mark the next piece. The catch is that after two or three generations of cuts, the length can begin to grow longer. If, for example, each stud is off by 1/16 in., after you cut four studs, you will be off 1/4 in. For accuracy, it is better to use one master pattern and use it for every cut.
A 15-year loan is usually made at a lower interest rate. Equity is built faster because early payments pay more principal. In a 30-year loan, more interest is paid off than principal for the first 23 years, meaning larger tax deductions. As inflation and costs of living increase, mortgage payments become a smaller part of overall expenses.