Most of the best views in the High Country come with a slope. A steep lot can make a great homesite. It can also change the foundation, the driveway, the well and septic, and the budget more than any other part of the house.

We design and build custom homes on mountain lots in Boone, Blowing Rock, Todd, Seven Devils and across the High Country. Here’s what we look at on every steep lot, what it means for your home and your price, and what to check before you buy.

Walk it and survey it before anything is drawn

Every steep-lot project starts on the lot, not at a desk. We walk it with you to see where the house wants to sit, where the views are, how a driveway could climb, and where the water goes when it rains.

Then we survey the lot ourselves with GPS survey equipment and bring the terrain straight into our design software. That way the house is designed on the real ground, not on a flat sheet of paper, and the foundation, driveway and septic area are worked out before the floor plan is final.

Where the house sits decides the foundation

On a flat lot, the foundation is a simple choice. On a steep lot, it follows from where the house sits on the slope. Most of our mountain homes end up on one of three:

Crawl space. Works when the house sits across a gentler part of the lot.
Walkout basement. The back wall is buried in the hill and the downhill side opens to daylight, so the lower level can be real living space. If the grade works in your favor, a walkout is the best way to use that space.
Tall foundation. On a very steep lot, the foundation follows the hill down. Echo Pines, a cabin we built in Todd, sits on an 18-foot foundation that rises with the slope and puts the main floor up in the trees.

The foundation is one of the biggest swings in a mountain budget, which is why we settle it on the site walk, before design starts.

The driveway: grade, length and winter

A steep lot needs a driveway that a car, a concrete truck and a lumber delivery can all get up, and that you can still use after a snow. Grade, curves, a place to turn around, and where the driveway meets the road all get worked out up front. A short, simple driveway costs far less than a long one that switches back up the hill.

Septic and well on a mountain lot

Most High Country lots outside town limits need a septic system and a well.

Septic. The county has to approve the soil before a septic permit is issued, and the approved septic area often decides where the house can go. On a steep lot, there may be only one or two spots that work. Find out before you fall in love with a house site.
Well. Depth is hard to predict in the mountains. Our pricing typically includes a well budget for drilling up to 500 feet deep. If a well has to go deeper, the extra is priced by the foot.

Water, walls and engineering

Water runs downhill, and on a steep lot it runs toward the house if nobody plans for it. Grading, drains and how the yard is shaped around the house matter more on a slope than anywhere else. Where the ground drops off fast, retaining walls may be needed to hold it.

Our rule of thumb: if the ground falls more than about 10 feet across the footprint of the house, we bring in an engineer to design the foundation walls and footings. On some lots, a post-and-beam structure makes more sense than a tall foundation wall.

Getting crews and materials on site

A steep lot changes how the house gets built, not just how it looks. Concrete trucks, lumber deliveries and equipment need a way in and room to work, and some lots need extra site work just to make that possible. It’s part of what we look at on the first visit.

What a steep lot does to your budget

Homes typically start at $350 per square foot and up. At that price, a home often includes typical site work, septic and a well: clearing the home site, a driveway under 100 feet, drainage, and a well up to 500 feet deep.

A steep lot adds cost when it needs more than that: a longer or steeper driveway, retaining walls, a taller foundation, heavy rock, or a deeper well. For a broader look at what drives mountain building costs, see the hidden costs and perks of building a mountain home.

Because we price from finished drawings, those items are in your fixed price before construction starts, not surprises halfway through.

The most common mistake: buying the view first

The mistake we see most often is falling in love with the view without knowing what the foundation will cost.

We recently looked at a lot in Seven Devils for a client from Raleigh who had already bought it. The lot is so steep that the back of the house would stand on steel posts 40 to 50 feet tall to reach the ground. The foundation alone was going to cost more than $200,000, before a single wall of the house went up.

The view was worth a lot. It’s just much better to know that number before you buy the lot than after.

Before you buy a steep lot: a short checklist

Has the county approved the soil for a septic system, and where?
Where would the house sit, and what foundation would that take?
How long and how steep would the driveway be? Can a truck get up it in winter?
Are there neighborhood (HOA or architectural review) rules, or Blue Ridge Parkway view and setback rules? See building near the Blue Ridge Parkway.
Where does the water go in a hard rain?
Is there power at the road, and how far is it to the house site?

If you’re looking at a lot now, we’re glad to walk it with you before you buy.

Common questions

Can you build on a really steep lot?

Often, yes. Maple Hollow, our A-frame in Seven Devils, stands on tall posts down the slope, and Echo Pines sits on an 18-foot foundation. The question is usually what it will take, and we answer that on the site walk.

Does a steep lot always cost more?

Usually some, and sometimes a lot. If the ground falls more than about 10 feet across the house, expect an engineered foundation. But a steep lot with a short driveway and a good septic site can cost less to build on than a gentler lot with a long driveway and poor soil.

Should I buy the lot before talking to a builder?

If you can, talk to us first. A site walk before you buy can tell you where the house would go, what the foundation and driveway would take, and whether the septic will work.

Can you build from my own architect’s plans on a steep lot?

Yes. We’ll add the site plan if the set doesn’t have one, because on a slope it shapes everything else. Here’s how building from outside plans works.

Start with a site walk

Whether you own a lot already or you’re still looking, the first step is the same: walk it with us. Start a conversation or call (336) 990-9420. See how a build moves from start to finish on our process page, and more of our mountain work on our High Country page.

ExCo Custom Homes · 913 Main Street, North Wilkesboro, NC · NCGC #78996