The Hillside Lot Field Guide: What to Know Before You Build on a Slope

A lot of the best views in the Valley come with a slope attached. Hillside building lots are some of our favorite jobs, and they're also the ones where a little planning up front makes the biggest difference. Here's what we walk through with people who are thinking about building on one.

Rock changes everything

On a flat lot in town, most of what we move is dirt. On a hillside, a lot of it is rock. Some of it breaks up with a bucket. Some of it needs a hammer, and some of it needs blasting.

You usually can't tell which one you have until you start digging, and that's the biggest reason hillside work is harder to price than flat work. When we come out for an estimate, we'll walk the lot and look at what's showing on the surface. We'll tell you what we expect to run into and be straight with you about what we can't know until we're in it.

Access to a hillside lot comes first

Before anything gets built, the equipment has to reach the spot. On a lot of hillside parcels, that means cutting an access road or a driveway first. It's often the first real piece of work on the property.

Think about where your driveway will eventually go. If the access we cut can become your driveway later, you save yourself from doing that work twice.

The pad is the foundation of the whole project

Your house sits on a building pad: a flat, level, compacted area cut into the slope. Where it goes and how big it is affect your views, your driveway grade, how much rock gets moved, and what happens to the material that comes out.

This is a good conversation to have with your builder or designer before the plans are final. Small changes to where the house sits can make a real difference in the dirt and rock work.

Water runs downhill, fast

It doesn't rain often here, but monsoon storms can send a lot of water down a slope in a short time. Once a pad is cut, that water needs somewhere to go besides your foundation, your driveway or your neighbor's lot. Grading for drainage is part of hillside work from day one, not something to fix after the first storm.

Dust and loose soil

Cutting into a hillside exposes soil that hasn't been disturbed in a long time. Keeping the dust down during the work matters to you and to the neighbors. Some ground also needs stabilizing before it can carry a building. We'll look at both before we start.

Check the local rules early

Many cities and counties have extra requirements for building on slopes. Rules differ from place to place across Maricopa, Pinal and Yavapai counties, so check with your city or county early in the planning process. Finding a slope requirement after the plans are drawn is the expensive way to learn about it.

J-King Excavation has been excavating around the Valley for over 40 years, and hillside building lots are one of our specialties: mountainsides, rock work, access, building pads, grading and drainage.

If you're looking at a hillside lot, we're happy to come take a look. Estimates are free. Call us at 623-231-5697 or visit j-kingexcavating.com.