How Much Slope for Walk-Out?

Karen asks: We are considering buying a property that’s labeled as “gently rolling”. Do we need a builder to look at it in order to tell us if a walk-out basement is possible? How much slope is required?

Steve Bliss, of, responds: Assuming an 8 ft. foundation wall, and assuming your foundation projects one foot above grade at the front of the house, you need approximately a 7 ft. change in elevation from the front of the house to the back for a walkout.

Much more slope than that would be expensive to build on and might require expensive retaining walls. A little less slope (4-6 ft.) is fine as the house can be raised in front, or the grades adjusted a bit in the finished grading. In general, walk-outs are a little more expensive to build in cold climates as deep footings are required on the walk-out section of the basement.

Caption here

CLICK TO ENLARGE                        With a walk-out basement, the footing must be stepped down to remain below the frost line along the side and lower walls.

As to whether you have enough slope at your desired house site, you might want to have a builder or house designer take a look. There are often constraints as to exactly where on the lot you can build a house. These include setbacks, septic location, drainage issues, road access, etc. On smaller lots, there are only one or two practical places to site a house, so you would need establish at least a preliminary house site before addressing the walk-out issue.

See also Building On A Slope



Please enter correct number before posting – to prove you're a person. * Time limit is exhausted. Please reload CAPTCHA.

Home | About Us | Contact Us | Privacy Policy
© 2017 BuildingAdvisor ®; All rights reserved.