Should You Choose A Post And Pier Or Slab

Are you wondering if you should buy a home with a post and pier or a slab foundation? In this episode of Aloha O'ahu, we’re going to talk about the two most common house foundation types so you can choose the right one for you. We’ll look at the benefits of each and find out which option I prefer over the other.

The Post and 'Pier Foundation

There are two types of foundations commonly found on O'ahu. The first foundation style that is prevalent across the island is the post and pier design. Just like the name suggests, a post and pier foundation home is raised anywhere from three or more feet off the ground on posts. Those posts rest on the pier, and that pier then rests on a concrete block footing—sometimes known as a tofu block.

Over the years, building codes have changed. Older homes can be retrofitted so that they are anchored more securely than they used to be. You may ask, ‘Why would you want to build this way instead of just laying a concrete slab and putting a house on top of it?’ 

Building On Uneven Terrain

One reason that post and pier home building was and is still popular is that it can be more easily built on uneven ground. In order to lay concrete slab, the ground must be level. On some parts of the island—especially those with more rocky terrain or sloped areas—laying a slab is very difficult to do. This means the post and pier design makes more sense. 

A post and pier foundation allows you to have a home with different length posts underneath if you are on a slope. Even if your terrain is flat, post and pier homes are easier to build. Also, there are some benefits that you do not get with a concrete slab foundation. 

Making Repairs

When you build a home a few feet above the ground, a primary benefit is the ease of repairs on a post and pier home. On this type of home, electrical and plumbing run below the home where it can be easily reached from underneath. If you have a main pipe that's leaking underneath your house, the plumber can crawl in underneath, diagnose the problem, and repair it much more easily. 

For a home built on a concrete slab, plumbing and electrical repairs often require breaking into the foundation or the walls to make the repairs. This drives up the time to find the problems and increases the cost of repairs. Personally, I like the idea of having peace of mind knowing that on a post and pier home, someone can quickly and easily reach a problem area in an emergency.

Cool And Dry

Another great benefit is that post and pier homes are naturally cooler. We rely on the trade winds to assist in naturally cooling our homes with a post and pier home. The wind goes below the living areas, which also assists in cooling the home. The increased airflow also helps to reduce mold that can be of concern in our tropical environment. 

In our tropical climate here in O'ahu, we do have to worry about rain and potential flooding. A well-designed post and pier home definitely outperforms a slab home when there are heavy rains. While it will not prevent flooding in your home, it is much more difficult to flood when you are several feet off the ground. 

When Concrete Slabs Are better

While I've tried to lay out several benefits of the post and pier design, it may not always be the right answer. Depending on how the house is built, a post and pier home may not be able to handle some heavier wall types. Many post and pier homes are made with single-wall construction, so if you want a more traditional mainland-style home with double-wall construction, then a concrete slab might be right for you.

 There are definitely parts of the island where a concrete slab makes sense. When building posts and pier homes in the past, it was an economical way to build homes, and minimal concrete was needed. Now with current building codes, more concrete is required—which has greater economic and environmental costs. 

Choosing Your Home’s Foundation

If you're going to buy a home or you already live in a home that has a post and pier foundation, there are many perks to enjoy—including its classic feel. If you have any additional questions about different styles of homes here on O'ahu, please do not hesitate to reach out and ask.