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6 Hidden Costs You Must Know Before Building A Home Addition

By on Mar 20, 2014
6 Hidden Costs You Must Know Before Building A Home Addition

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Homeowners know certain costs come with home additions. These expenses range from hiring a contractor and buying materials to perhaps taking time off work to do it yourself. Like any project, there are other hidden costs the average homeowner doesn’t think of when it comes to home additions. These can include permit charges, plumbing and as always, surprise fees you can’t anticipate. Make sure you keep your project on schedule and under budget by preparing for these hidden costs associated with all home additions.

Before jumping in, homeowners should know that there is always a light at the end of the tunnel, which we highlighted in the 7 Benefits Of A Home Addition.


If you are adding a kitchen or bathroom to your home, finding the right plumber can be critical. An addition drives up plumbing costs dramatically since there is rarely any type of existing plumbing to use. Adding plumbing is a very labor-intensive job that must be done by a professional. Specific building codes must be adhered to and a fully licensed and reputable plumber can provide ease of mind. 

Quick Tip: You can lower your budget with the use of the cheaper ABS piping instead of PVC.


No matter what type of room you are adding, you will need an electrician. Oftentimes, a new breaker must be installed from the main panel and the various boxes needed to deliver power to fans, outlets and light fixtures. Just like plumbing, electrical work is subject to a very high level of scrutiny by building and fire inspectors. Hiring a professional electrician will ensure quality and up-to-code work.


Speaking of code, almost every home addition will require a building permit.

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Permit costs are generally based on the estimated construction cost of the project. Depending on the project, electrical or plumbing permits might be required. On top of that, an application fee may be necessary as well. Believe it or not, permit fees can often exceed hundreds of dollars.

In addition to money, your free time could take a hit as well. Not all contractors agree to pull the permits for you. Quite often, general contractors put that burden on the homeowner. Nonetheless, we highly recommend you have the contractor pull the permit. Certain states even require it. You may save a few bucks by not paying a contractor to pull the permits, but the added responsibility to the project and time commitment with the building departments are most likely not worth it.

To ensure you know all the expenses going into a contracting job, be sure to review our five essential questions all homeowners need to ask their contractor before any remodeling job.

Surprise Fees

No matter what type of remodeling job you undertake, there will always be surprise fees that you or your contractor cannot predict. With home additions, a big assumption is that the land can hold the added square footage. Depending on the project, the contractor may have to bring in special tools to dig up the land and add new concrete. The contractor can’t know how strong or weak the land is until they get in there. As a result, they may need to use different tools than originally expected, altering your home additions budget.

Quick Tip: Homeowners should always add a special section in their budget for unanticipated fees. They may be a surprise, but they almost always occur in home remodeling.

Garage Installation Hidden Costs


If your addition is a garage, homeowners will also need an experienced mason. A concrete slab must be poured with extreme caution and completely level to prevent future pitting and cracking. In addition, an epoxy or polyurethane coat will be needed to properly seal the floor and protect it from tarnishing, staining and flaking. Also, as we discussed in the surprise fees above, a mason may be required if your foundation needs to be extended for other home additions. 

Storm Shelters

Some homeowners may be extra cautious and want to add a storm shelter. Given the recent weather across the United States, no one would blame you. However, like other home additions, storm shelters also have hidden costs.

Many cities and states require you to apply for a building permit before starting construction on a storm shelter. This permit could cost anywhere between $50 and $200. Land could also affect your budget. If your terrain is rocky or uneven, the shelter will be difficult and more expensive to construct. Finally, as is the case with any home addition, the size of the shelter will play a key role in the final costs.


There will always be unanticipated costs that pop up with home remodeling. Additions are no different. Before you start your home addition, be sure to address and account for these hidden cost so you can finish your project on time and under budget.

For a more in depth look at the hard numbers associated with home additions, be sure to read our home additions cost estimator.

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