Say you normally have an asset allocation of like 90/10 stocks/bonds. What if you upped your normal investments to like 100/0 and then started paying off the house a ton. If done right that extra principal payment on the house could effectively become the equivalent of investing in a guaranteed ~2.5% (because of the loss of the interest tax deduction) investment which could effectively bring you back to 90/10 asset allocation. What other details are being overlooked here? I know there are some but can't quite put my finger on it.