What You Should Know Before Adding a Bathroom to a Basement

While adding a bathroom to your finished basement can be useful and a solid investment, some challenges come with belowground plumbing. You’ll need to consider drainage and ventilation when designing your belowground bathroom. This home improvement job is best left to a professional bathroom remodeler.

Pros and Cons of Adding a Bathroom to Your Basement

As with any home project, installing a bathroom in your finished basement has advantages and disadvantages. Consider each one to determine if this project is right for you.

Pros

Adds Convenience

If you decide to transform your finished basement into a kids’ playroom, a home gym, or a guest suite, adding a bathroom will only improve the space. Your guests will feel more comfortable in their own space, and you’ll no longer have the whole family running up and down the stairs to use the bathroom throughout the day. A bathroom in your finished basement is the ultimate convenience.

Boosts Home Value

Adding a bathroom to your basement or remodeling an existing bathroom can also increase your home’s value. If you go with a full bathroom complete with a shower or tub, you’ll make the space fully livable. And if you also add a kitchen or kitchenette, you could even rent the space out.

Cons

Takes Up Space

If you’re considering installing a bathroom in your finished basement, consider how much space you have. Some basements are as large as the entire footprint of the upper stories of the home, but others are smaller. Keep in mind that adding a bathroom will remove some of that space, leaving less room for your treadmill or the kids’ action figure collection.

Not DIY-Friendly

Installing a belowground bathroom isn’t a DIY-friendly project and requires a professional to work out the details. Basement bathrooms come with unique challenges—running water downstairs and back up again can be tricky, so it’s important to hire a pro who knows what they’re doing to ensure that your bathroom works properly. A local bathroom remodeler can walk you through the project and create an estimate. 

Can Be Costly

Because adding a basement bathroom requires a professional as well as new plumbing systems, it can be costly. Plumbing prices vary, but this type of project can easily cost between $10,000 and $15,000.

Things to Consider Before Adding a Bathroom to a Basement

Here are the most essential items to consider as you plan to add a bathroom to your basement.  

Design Options

First, contact your local building authority to understand what zoning ordinances to consider and to secure the proper permits. Then, plan your basement bathroom’s design.

Decide which style of bathroom you’d like. Your options are:

• Half bath (toilet and sink only)

• Full bathroom (toilet, sink, and shower or tub)

Half baths work well in basements because they’re functional but require less maintenance than full bathrooms. 

Full bathrooms are nice when you’re converting your basement into a guest space. That way, they don’t have to trudge their things upstairs to take a shower. But make sure to add a high-power ventilation fan to draw out excess moisture since basements tend to be damp even without a bathroom.

You should also take your bathroom’s flooring into consideration while designing the room. Bathrooms can be wet, so the flooring you choose must withstand exposure to moisture. Vinyl, tile, and concrete are good options.

Consider Plumbing

Plumbing-wise, it works best to install your basement bathroom directly below the bathroom on the upper floor. This will simplify plumbing and eliminate the need for pipes to twist and turn throughout the house, which will require more materials (and more cost).

Talk to a professional about the depth of the sewer line. If it’s deep enough, you can install belowground water and waste pipes to allow gravity to take care of waste disposal for you. But if it isn’t deep enough, which is a common occurrence, you may need to consider other waste disposal methods, including:

• Sewage-ejector systems

• Upflushing toilet

• Pressure-assisted toilet

If your house has a Pittsburgh toilet—a standalone basement toilet—you can finish a bathroom around it, and you may already have some of the plumbing in place.

Ensure Proper Drainage

It’s crucial to consider drainage when adding a bathroom to a basement. Unlike in above-ground plumbing, belowground plumbing can’t harness the power of gravity to drain waste towards your pipes. Your plumber can help you determine how to combat this issue to ensure proper drainage and waste disposal.

Some basements will have deep drainage lines, which makes waste disposal a bit easier since gravity can get to work. But in cases where those lines aren’t deep enough, you may need to tear up part of your basement floor and dig into the ground below it to create sufficient fall that will encourage proper drainage. 

Your plumber is the best resource here, as plumbing systems vary from home to home. Installing a bathroom in your basement can be difficult and costly, but most homeowners find it to be worth it in the end.

Storage Space

If your basement bathroom will be used frequently, you may need to consider storage space–like a linen closet–in your design plans. It might make the bathroom project larger, but it’s worth getting it done right, especially if you need the space.

Flooring

Since this bathroom will be in your basement, you should be extra careful when selecting your flooring material. You should avoid using solid hardwood and laminate flooring in a basement bathroom, as these materials are prone to buckle and warp when exposed to excess moisture.

Cost to Add a Bathroom to Your Basement

Adding a bathroom to your basement will cost between $10,000 and $15,000, depending on how much plumbing and electrical you need to add. You’ll also pay more for luxury materials and special drainage if you’re below the water table. Building a basement bathroom directly underneath an existing bathroom can reduce plumbing costs in some cases, as well as take other existing architecture like columns and existing walls into account.

DIY vs. Hiring a Pro

If you have the skills and tools to safely and properly install a bathroom in your basement, it could save you money on the cost of labor. That being said, you may want to contact a basement contractor near you and have them do the job if you’re hesitant about it or don’t have the time to do it yourself. Plumbing and electrical have to be worked on by licensed professionals, and DIY mistakes can lead to costly repairs. With this in mind, hiring a pro for the job is the best way to go.