transforming a crawlspace into a basement: guidelines and exceptions
Space plays a significant role in our desire to purchase a house, often prompting us to start planning for a bigger one as soon as we move into our current one. However, despite years of growth, houses have been getting smaller in recent years. In 2015, the median size of a house was 2,519 square feet, but last year, it dropped to a mere 2,191 square feet.
According to a common rule of thumb, you need around 600 to 700 square feet per person living in a house. Therefore, for a family of four, the ideal size would be about 2,400-2,800 square feet. Size up your home, and you could potentially increase its value by 30%. But gaining additional square footage can be challenging, especially if you are short on space to expand. If you don't have enough outdoor area, are constrained by zoning laws, and your crawl space is limited to crawling only, you may wonder if digging down is a viable solution.
The idea of digging out a crawl space is simple: You remove the dirt and other debris from the floor, lowering it until you have a usable amount of headroom. However, it's not as straightforward as it sounds. Extending and reinforcing the foundation and footings through underpinning or buttressing are also necessary. Several factors contribute to the difficulty of deciding whether or not you can dig out your crawl space:
- Soil: The kind and condition of the soil your house was built on is crucial. Soils that are loose and sandy are more likely to collapse during the process.
- Age: Houses constructed before the 1950s typically have foundations made from non-reinforced concrete and thinner footings, increasing the difficulty of a dig-out.
- Foundation: The type of foundation is also important. Older foundations made from bricks are less stable, especially if the mortar is sandy. Monolithic concrete foundations are more suitable for dig-outs.
If you consult with a structural engineer and determine that it's feasible to dig out your crawl space and integrate that additional square footage into your house, you're still faced with another question: is it worth it?
Problems
Digging out your crawl space to create a livable space may have several adverse consequences:
- Expense: The total cost to dig out a crawl space and turn it into a finished basement can reach up to $200,000. Even if you manage to sell your home for an additional 30% due to the new basement, it might be challenging to realize a good return on investment.
- Safety: There's a risk that your home could collapse during the excavation process. Even with the utmost care, the foundation can weaken and shift, leading to a chain reaction of failure, resulting in no new basement and potentially no house.
- Insurance: Given the increased risk, it's recommended that you receive additional insurance for this project, particularly since structural instability could affect your neighbors as well. Be prepared for the potential financial consequences.
- Timeline: This is not a quick project. It may take weeks to dig out your crawl space, and you might have to leave your home during the process.
Final Thought
Do you have a crawl space that you try to avoid, dreaming of a finished basement or accessory dwelling unit? Only proceed with a dig out if you can answer "yes" to these questions:
- Are there no other options to add square footage to your home?
- Was your home built after 1950 or so?
- Has a licensed structural engineer inspected your property?
- Are you prepared for the monetary and potential liability costs?
If your answer is "no" to any of these questions, leave the shovel alone and stay away from your crawl space.
(Note: Here's a link directing to a related article if you want to read more about this topic.)
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Despite the challenges, you might consider turning your limited crawlspace into a more functional basement space. Transforming your home by digging out the crawlspace could potentially increase its value significantly. With proper planning and consultation with a structural engineer, you can assess whether this project is worth the investment and feasible for your home.
