Home Building Cost Estimator

"Hi Carl,

I went through the building cost estimator and have a few questions.

The final price you get including "contractor markup". If I was to be my own General Contractor would I take %25 off the total or just remove the contractor markup to get a more accurate estimate?

My second question is I noticed an unfinished walk-up attic on my house spec was about a $60,000 premium (Total 1,067 sq ft).
Does this make sense? It seems I have been in many houses that have large walkup attics and they are in cheaper homes sold in my area.


Hi Dan,

The "Cost to Build" calculator is not intuitive. It is a great tool to “play around with” when you are in the very, very early stages of planning a home. It is NOT a substitute for getting out there” with sets of plans and getting bids and estimates.

Even touring new construction open houses that are similar in design to a home you would like to build and then deducting 25% from the builder’s selling price, is more accurate than the calculator…providing of course, that the builder is not selling the house at a distressed price due to the economy.
Read my “Cost to Build a House” on http://www.byoh.com/.

To determine the amount of savings you may achieve by acting as your own General Contractor, review some of the estimates that I performed on houses on my “Cost to Build a House by State” page and you’ll see that I deduct the General Contractor’s Markup, equipment rental, and a lesser amount for Homeowner’s (Builder’s Risk”) Insurance to come up with the estimated savings you are looking for.

As for the calculator showing the attic at a $60,000 premium for 1,067 sq ft, the calc is merely “assuming’ the worst case scenario and adding a steep roof, ceiling and wall framing, and floor joists of sufficient size to carry a load, as well as permanent (built to code) stairs.
In reality, building a house with a steep enough roof to accommodate a usable attic actually covers the major cost of building an attic

Carl Heldmann, byoh.com