Last week, I submitted all the information to obtain a building permit for my workshop that will be built behind our garage. The building was to be 18′ x 32′ and would be located 14 feet behind the garage. I had to submit a detailed description of the building, as well as several drawings. I submitted much larger versions of these drawings that I have already shown you.
I also presented this plan of the building…
I also had to submit a plan showing our property with the existing structures and where the new building would be located. So I submitted this…
I thought I had it all covered, but when I checked my permit status yesterday, it said it was on hold because I hadn’t filed a foundation plan. There was also this note: “New foundation over 500 square feet will require an engineer-stamped design.” And my shop was planned for 576 square feet. Ugh.
So there’s good news and bad news. The bad news is that there’s no way I’m going to spend money on an engineered foundation for a shop that’s being built by a local shed company. So I have to downsize my shop to get it as close to 500 square feet as possible without going over. My shop will now be 18′ x 27′. I’ll lose five feet of width in the building, which is a real bummer, but I’m okay with that. The shop will still be about 86 square feet larger than my studio and garage, so that’s a very nice size. I’m okay with that, especially if I can avoid the expense and hassle of having to have an engineered foundation.
The good news is this. The only thing that was keeping me from feeling confident about being able to act as my own contractor on the kitchen addition was the foundation. I kept hearing the term “engineered foundation” and I had no idea what it was. I spent several days trying to google and research to find information and answers but I couldn’t find anything helpful. I tried looking on my city’s permits and inspections website and couldn’t find any information. I couldn’t find any answers to my questions. What is an engineered foundation? Do I need an engineered foundation? If I do, where can I go to get it? I had so many questions but couldn’t find answers.
And yesterday, on a completely different and unrelated project, the information I was looking for arrived in my email inbox directly from a building plans examiner in my city. Ha! Perfect! Here’s what I learned…
What is an engineered foundation?
In simple terms, an engineer-designed foundation takes into account many factors such as the foundation of the existing building (if any), the condition of the existing building’s foundation, the type of soil on which the building or addition will be built, etc.
This is probably not the case in all jurisdictions, but my understanding is that in my city the city does not have to inspect the engineered foundations because the engineer is the one who signs off on the engineered foundations and they are filed with the city. But again, each county or city may have different requirements.
When is an engineered foundation necessary?
To find out whether or not you need an engineered foundation, you’ll need to check with your local building permit and inspection office. But to give you a general idea of when it may or may not be necessary, I’ll share the specific requirements for Waco, Texas.
Existing pier and beam house:
If you are building an addition on a pier and beam home, and the addition will also be pier and beam, there is no need to design the foundation for the addition as long as the existing foundation has not failed.
Existing slab foundation:
This is the same as the current requirements for piers and beams. As long as the addition has a slab foundation and the existing slab has not failed, the addition will not require an engineered foundation.
Conditions:
- An engineered foundation is required if the addition will have a different type of foundation than the existing structure. If a home has a pier and beam foundation, but the addition will have a slab foundation, an engineered foundation is required. Or if a home has a slab foundation, but the addition will have a pier and beam foundation, an engineered foundation is required. An engineered foundation is also required on an addition if the existing foundation has failed.
- New foundations must be designed for stores, storage buildings, and residential additions of 500 square feet or more.
Those are the specific guidelines for Waco, Texas, as of summer 2024. And if you’re not in Waco, those guidelines can give you a general idea or starting point as to whether or not you need an engineered foundation for your addition or accessory building. But of course, you’ll want to get the specific permits from your own inspection office.
Now that I have this information, I really feel like I could be my own contractor. I feel more empowered with this information and better prepared to make a decision. I’m still not sure whether or not I will opt for an engineered foundation for my kitchen addition, but at least now I know what the city requires. And if I do choose a pier and beam foundation for the kitchen addition, no engineered foundation is required since (1) the existing house has a pier and beam foundation, (2) the existing foundation is in excellent condition and does not have any points of failure, and (3) the kitchen addition is less than 500 square feet.
Addicted 2 Decorating is a place where I share my DIY and decorating experience while remodeling and decorating the 1948 home my husband Matt and I purchased in 2013. Matt has multiple sclerosis and is unable to do physical labor, so I do most of the work around the house alone. You can learn more about me here.
