Difficult Building Sites - Mountain Home Building Site

Hi Carl, I would just like to get your input/insight on the best approach to building on a steep slope. My wife and I bought a 5 acre property on a side of a hill in Colorado.

My guess is that the elevation from the bottom to the top of the hill is about 100-150 feet and the slope varies between 20-30%.

I think I'm going to need a grading plan or topography survey of the plot.

Another potential issue is the amount and size of boulders on the property.

We might have to hire someone to blast/dynamite the area where the foundation will be built. Any advice you could give us would be greatly appreciated, Neil

Hi Neil,

Since you didn’t give me the actual lot dimensions I am going to assume (you know what that spells) that the lot is almost square. That would make each side dimension approximately 468 ft.

Unless I calculated wrong that would mean about a .25 ft drop per running foot.
So, a house with a foundation 30 feet deep would have an approximate difference of 8 feet from the front wall to the back wall. That’s not too bad

You also need to be concerned with sewer/septic availability and their location.

Did you investigate this before you bought the land? I hope so.

If there is sewer, is below your planned building site or above it. If it’s above, you will need a lift station and they only pump just so high.

If a septic system will be needed, did you check with the local municipality as to system requirements, including the location on your lot? A 20-30% grade would probably require an alternate system.

Lots of things to investigate before you can even “locate” or position the house on the lot.

I would consult with a local architect familiar with mountain building, and who knows and can refer you to a local engineer.

An engineer would be the logical person to consult with as to the boulders and location of the house.

Without knowing the size of your boulders, I could not begin to guess what you need to do. Can they be moved? Can you build around them?

You may or may not need a topography survey. For those of you who might be interested, a topographical survey (Topo) is a survey that shows contours, natural and man-made features, and elevation gradients.

You have your work cut out for you, but as usual, most of it is investigation and planning.

Be sure you provide a rugged temporary driveway (see Paving Mountain Driveways)  to your building site. I learned that the hard way.

I have done two mountain houses. They both were challenges, but well worth it.

Good luck,
Carl Heldmann, byoh.com