Structuring Your Remodel: Basement Renovations
/An unfinished (or poorly finished) basement can be as good as a blank slate for you to add livable space and make your home your own. When we bought our house in 2013, the basement was effectively finished, but far from comfortable or livable. We took the opportunity to tear down some walls, insulate the exterior, and revise the floor plan to work better for our vision and our family. In this time when home prices keep us in place, perhaps the next expansion you need is already right below you!
A few of the challenges I’ve seen in basements include posts and beams in the way of your ideal floor plan, as well as low headroom, and egress limitations.
Posts & Beams
When older homes were originally constructed, basement living space may not have been a consideration. We can often see that in the efficiency of the floor structure above and a higher frequency of columns. As with any other structure, to remove a structural element, something else must be put back. Posts in the basement can often be traded out for a longer beam and new posts. The trade-off tends to be head room. The longer the beam is, the deeper it wants to be to resist the load and be stiff enough that you don’t feel it upstairs.
Low Head Room Solutions
When the home is originally constructed without a living space in the basement, the head room available down there is not always enough. National, state and local codes have minimum head height requirements for living spaces – typically between 7 and 7.5 feet. The head height is the clear distance between the top of the finished floor and the bottom of the lowest point of the ceiling. You have a few options to gain some of that space back. Bear in mind this is just the structural perspective, and other project components such as egress, fire safety, and geotechnical requirements must also be considered.
If your head height is close, relocating mechanical ducting and trying to modify the structure that’s in the way may be enough to get you the vertical space you need. Beams can be “tucked” up into the framing, or replaced with a stronger engineered lumber, or steel to gain strength and stiffness in a shallower depth. It’s important to be mindful of the space you’re opening up, the beam span you will need, and whether or not you’ll be able to get that span into the space successfully. In some cases, your structure will be limited to the means you have to get it into the house. Does the beam have to navigate stairs, or can it come in a window?
While considerably more expensive, the next two options give you quite a bit more flexibility as to the end result of your basement.
First, you can choose to raise the wood framed portion of the house and pour a new portion of foundation over the existing foundation. Some items to consider with a plan like this include reconnecting the house to the new foundation, the expense of jacking the house, as well as the condition of the existing foundation. If the existing foundation has enough damage, perhaps this is an opportunity to not only add head room and functional space to your home, but to repour all or portions of the home foundation. A geotechnical engineer may need to make recommendations based on your specific location as to how that extent of foundation work should be done. This is not necessarily a feasible option for homes constructed of other materials such as brick.
Finally, with the thumbs up from your geotechnical engineer, you may also consider removing your basement slab and excavating out the soil below to add height in the downward direction. Some items to consider include the process of removing soil from your basement space, and the likely case that you’ll need to pour new foundation wall and footing. Additionally, any existing wall or column that met the exiting floor will need to be replaced with a full height framing member to the new foundation level.
Checking Out Your Foundation
While you have your basement torn apart, give your foundation a good look over. Big red flags include large cracks, water intrusion, or visible displacement of the foundation from where it appears it should be. Contact your local engineer for an assessment or monitor the foundation yourself for specific, measurable changes in its condition. While looking over your foundation, look to be sure there is anchorage from the wood framing of your house to your foundation. Ideally, you’ll be able to see anchor bolt heads on top of your bottom plate. Lastly, I always recommend taking lots of photos throughout your remodel as a frame of reference. You never know when you’ll need to know what was behind the drywall at that one location.
Do you have future plans to upgrade your basement space? What’s your number one priority with that space?
Check out the entire Structuring Your Remodel series!
1 - Structuring Your Remodel - Interior, Kitchen & Bath
2 - Structuring Your Remodel - Exterior, Roof & Decks
3 - Structuring Your Remodel - Basements
Disclaimer: Although I am an engineer by profession, I am not YOUR engineer. All content and information in this post (and on this website) is for informational and educational purposes only, does not constitute professional advice and does not establish any kind of professional-client relationship by your use of this website. Refer to my full disclaimer for more information.
