Bathroom Fans, Bathrooms, Electrical

Do You Need a Permit to Install a Bathroom Fan

Person Removing Bathroom Vent Lg
Installing a bathroom vent fan

A bathroom makeover is an excellent idea for improving the appeal and convenience of the bathroom. One of the vital makeover moves is to install a bathroom fan. While you don’t need a permit for cosmetic bathroom improvements for installing a new bathroom fan, the narrative is different. 

If you replace an old vent fan with a new fan, you won’t need to obtain a permit. However, when installing a new bathroom vent fan where one did not previously exist, you will likely need a building permit.

A new fan installation will require some electrical wiring and likely need a permit to verify that the installer follows local codes and safety guidelines. Enforcement of building codes is done at the local or county level. You should check with your local municipality to determine if a permit is required.

Do You Need a Permit to Install a Bathroom Fan?

You need a permit for any electrical circuit improvement project that you undertake. Hence, since installing a bathroom fan is one such process, you require a permit before installation. 

It sounds petty that the government requires you to have a permit for a minor project such as a bathroom fan installation. Nonetheless, the key aim is to shield you from electrical mishaps due to poor installation. The authorities ensure that you have met all the safety requirements first by giving a permit. 

It’s noteworthy that you do not require a permit in all bathroom installation projects. For instance, if you are not doing any rewiring, there is no need to ask for a permit when you want to replace a dysfunctional bathroom fan with a new one, such a case. 

Also, not all local regulations require you to obtain a permit to install a bathroom fan. Hence, you need to consult with your authorities first. The building department in your locality is responsible for issuing such permits. Consult them for a guideline on what you must fulfill to receive a permit. 

How Do You Apply for a Permit to Install a Bathroom Fan?

If you need a permit, the local building department will furnish you with the requirements and policies for installing bathroom fans. Based on your information, they will check you against their requirements to see if you have fulfilled the prerequisites.

You will also be issued an application form. Fill it, then submit it to the authorities. Remember to attach all essential documents that you need to provide to approve your application quickly. 

Also, pay the application fees if there are any charges. As the duration of processing the permit will vary, it’s best to apply earlier than your scheduled application date. Make sure to confirm the time it may take for the entire processing of the permit.

How Much is the Permit?

The costs will vary depending on the size of the installation and many other details. A bathroom remodeling permit is usually between $150 to $600. 

The building department will give you the actual cost after evaluating the size and needs of your project. Also, it will provide you with the preferred payment method. It can be via a check, cash, or card payment.

The cost of the entire installation is also varied. On average, you need to have at least $350. But the price could be higher if you want to replace the entire unit. 

However, it is the labor costs that you should be wary of as they can rise to high figures. What you incur in labor costs will depend on your electrician. Hence, it can be hard to say with certainty the actual labor costs of the installation.  

Also, note that the more sophisticated the fan is, the more expensive it will cost to install. A complex fan will require more expertise in installation, thus the high cost. 

Can You Have Someone Apply on Your Behalf?

Whether someone can apply on your behalf will depend on if you’re considering hiring a contractor or not. If you want to install the bathroom fan yourself, you’ll have to make the application. You cannot send another person in such a case. 

However, if you want to hire a contractor, the professional can apply on your behalf. In a nutshell, the actual individual who will do the installation needs to make the application. 

Can You Install a Bathroom Fan Yourself?

If you are conversant with electrical installations, you can install your bathroom fan. However, the ideal way is to hire an electrician. There is a chance of getting something wrong if you are unsure about the installation process. 

On the other hand, an electrician has the expertise and the tools to make a perfect installation. You may also find that your remodeling project requires more than just fixing the bathroom fan. You could need some ductwork. In that case, hiring an HVAC expert would be the best option. 

The expert will also take the responsibility of applying for the permit. Hence if you are busy or don’t want to engage in the hassle of getting a permit, ask an expert to do it for you. Do not ignore installing a bathroom fan because you worry that the permit application process could be tedious. 

Do You Need an Electrician to Install a Bathroom Exhaust Fan?

Given the apparent danger that a poor installation will predispose you to, it is advisable to hire an electrician. You will undoubtedly incur more than you would if you did the installation yourself. Nonetheless, you’d rather spend on labor costs than do a poor job. 

However, if it is a simple replacement, there is no essence of hiring an electrician. For instance, if you need to remove a faulty fan and replace it with another, you can do it yourself. But make sure that you are aware of what you’re doing. 

Is a Bathroom Fan Required by Code?

Building codes do require a bathroom fan. They can be mandatory even if your bathroom has windows in some localities. Often, most bathrooms will have a small window that does not necessarily open. In that case, a bathroom fan will most likely be mandatory. 

However, the application of codes depends on your community. You should check your local municipality to determine if a permit is needed. 

Also, there are many advantages to installing a bathroom fan light combo. Hence, you should consider installing it even without being compelled by code. 

While bathroom fans are a legal requirement, you can afford to ignore them, especially if you’ve got a window. But having one is an unwritten rule towards having a well-ventilated bathroom. You can achieve ventilation primarily through two means. 

  • First, you may erect a window at a strategic point in the bathroom. It should allow good aeration. A window will also allow light to enter the bathroom, which is imperative in preventing moisture build-up. 
  • You can install a bathroom fan. It will remove the moist air from the bathroom. Nonetheless, if you do not have a window, you’ll have to install a light source. 

Being conversant with the codes and following them is essential when installing a new bathroom fan. However, if your house has a bathroom fan installed, most probably, the builders followed the codes during the initial installation process. 

What is Code for Venting a Bathroom Fan?

The venting code varies from one community to the other depending on the local building department’s requirements. But there are several vital stipulations that homeowners must consider when building bathrooms. 

You can consider following all the codes as there is no harm in doing so or sticking to your locality’s primary requirements. 

Section R303 of the International Residential Code gives the fundamental requirements in ventilation and lighting. Let’s look at each one of them in detail. Some areas no longer recognize an operable window as an accepted ventilation source.

IRC Code SectionExplanation
R303,3Bathrooms should have at least one window that can open.
R303.4Bathrooms should have an exhaust venting fan
M1507.2You must discharge exhausted air outdoors and not into another room of the house.

R303.3: Bathrooms Should Have Windows

The code requires bathrooms to have windows. The windows should also be possible to open when required. The average glazing area of the bathroom windows should be at least 0.3 meters squared. Half of the window should also be open.

With a window in the bathroom, it will facilitate aeration. Without a fan, a window will be enough ventilation, especially if you have no shower or bathtub. However, installing a fan will improve the aeration of the room, so consider having one.  

The window must also be well fitted and sealed. You may not get the window code requirements on windows right, especially if you have never installed them before. Hence, it is essential to have an expert who will handle the job for you. 

An expert will also advise whether a small window is enough or whether you need to have both a window and a fan. In a large bathroom, having the two will be better. 

R303.4: Bathrooms Should have Exhaust Venting Fans

Some areas use this code in place of the above code or in addition to it. It all depends on the regulations of the locality. Some locales indicate that having windows is not an excuse for not installing a bathroom fan. In such a case, you must at least have a fan, or both a fan and a window. 

The best thing is to consult with your authorities on how the code applies. Nonetheless, there is no harm in having both as they will adequately improve aeration. 

M1507.2: Exhausted Air Must be Discharged Outdoors

The code requires you to discard all the air removed from the bathroom outside the confines of the house. Hence, it discourages the deposition of exhaust air in the crawlspace. Depositing it in the attics is also prohibited.  The code aims to improve aeration significantly by expelling the air outside the building. 

The code must seem obvious as, ideally, the natural way to deal with exhaust air is to deposit it outside. However, many homeowners will consider discharging it to the attic more convenient. However, it becomes counterproductive as the moist air will undoubtedly find its way back to the bathroom. 

Many people use the attics, which is the easiest venting technique. The alternative method is to install an external method of discharging. It may involve drilling and installation of discharge pipes which is time-consuming. But it is worthwhile in improving aeration. 

Why Do You Need a Bathroom Venting Fan?

Bathroom With Ceiling Vent Lg
Luxury bathroom remodel

There are several reasons why installing a bathroom fan is significant. Let’s delve into some of the most important ones. 

1. Solve the Misty Bathroom Mirror Problem

Your bathroom mirror should ideally be clear. However, you may have noticed that the mirror gets misty, especially after taking a hot shower. You cannot see your image clearly in a foggy mirror. 

If you do not install a bathroom venting fan, especially in a space with a shower, you will always have to wipe off the mist on the mirror. The mist comes from excessive humidity that is prevalent in a poorly ventilated bathroom. 

Hence, you must have a properly-sized bathroom fan to expel all mist from the space. You could also consider installing bathroom mirrors with anti-mist properties. But that does not mean that you will not require a bathroom firm. The anti-mist mirror is only a bonus to having a well-ventilated room. 

2. Prevent Bacteria Incubation

Adequate ventilation is imperative in preventing the buildup of bacteria in the bathroom. Bacteria will replicate in a moist and damp environment. Hence, if your bathroom is not well ventilated, it will be an ideal breeding environment. 

Among the bacteria likely to grow in numbers in a moist bathroom include Streptococcus and Staphylococcus. The former bacteria is known to cause a sore throat. Hence, if your bathroom has poor ventilation, you will have frequent infections of sore throat. 

Considering that you spend quite some time in the bathroom, you cannot avoid a bacterial attack. In some cases, they can be life-threatening. Hence, you need to have the area well ventilated to prevent the probable health hazard. 

3. Stop Mildew and Mold Growth

Mold and mildew are expensive and tedious to remove. If your bathroom is poorly ventilated, removing mold and mildew is futile as it will grow again. They will thrive best in bathrooms whose humidity is more than 50%. Such dampness is common in bathrooms without bathroom fans. 

There are several problems with mold or mildew infestation. First, mold is a respiratory hazard. Mold will affect the capacity of your lungs to hold air, especially if inhaled for long. Excessive mold inhalation can cause an asthma attack. 

The problem with mold accumulation in attics is that they will spoil the air quality. You will be breathing contaminated air which is unhealthy. If left unchecked, the mold may cause severe respiratory disease. 

Also, remember that you may have no option other than to remove the mold. The exercise is expensive and tedious. Thus, you’d rather install a bathroom fan to prevent the problem rather than counter it while it has already occurred. 

4. Avoid Unnecessary Repairs

Accumulation of moisture will be harmful to your bathroom’s ceiling and floor. It is also likely that the walls will sustain damage, and you’ll experience paint flaking. Thus, you’ll often have to make constant repairs. 

If you do not solve the mold problem, your tiles will be affected, especially in the porous type. The solution is to ensure that you have to ensure that there is sufficient ventilation in the bathroom. A bathroom fan will go a long way in solving the problem. Hence, having one will solve a lot of problems. 

5. Avoid Disruption of the Air Conditioning System

If you lack a bathroom fan, you can be sure that the moisture from the bathroom will get to other parts of the house. Consequently, it will impact the temperatures inside the house. The problem with the additional moisture is that it will affect the functioning of your air conditioner unit. 

The HVAC will have to overwork to keep the house’s temperatures at optimal levels. As a result, your electricity bills will increase. On average, air conditioning in the US costs $114. With excess moisture from the bathroom, the cost could rise higher. 

Another issue is that the extra burden on the air conditioner will impact its operation life. As it will be more strained than usual, expect it to require repairs, cleaning, and other maintenance practices more often. You may even have to install the entire unit again after some time. 

Excess humidity is also likely to damage other electronic components. For instance, contacts and insulators will be affected by the increase in moisture levels in the house. If the moisture is excessive, expect water to condense in low temperatures. As a result, short-circuiting of circuits may occur. 

Therefore, to prevent the occurrence of such problems and air conditioning disruption, install a bathroom fan. 

6. Prevent Mold Growth on Clothes

Among the mold’s ideal growth surfaces include clothes and leather. Hence, if your house has excess moisture, expect to find mold even on your clothes. It will cause discoloration of the clothes and also cause the development of foul odors. 

Wearing clothes with mold is a health hazard as it will cause respiratory infections. For instance, you are likely to develop an Athlete’s Foot if you wear mold-infested apparel. Most fungal infections do not go away easily. Hence, it’s advisable to prevent their occurrence by installing a bathroom fan. 

7. Maintaining the House’s Aesthetic Look

Excessive moisture discharge can lead to wood rot if not properly vented. Also, the metallic parts are not spared by excessive moisture as they’ll most likely start to rust. 

The rotting of parts in the house and the apparent humid air will distort the house’s aesthetic appeal. Also, you will spend heavily to restore the house’s look to its original beautiful appeal. Instead of such issues, it’s cheaper to install a bathroom fan. 

8. Stop Bug Infestation

Some bugs, such as bed bugs, thrive best in humid and moist environments. Hence, If your bathroom lacks a fan and adequate ventilation, the environment will encourage bugs infestation. 

Also, remember that moist air will cause cracks in your wooden upholstery. The cracks will provide a viable breeding environment for bugs. Hence, having a fan is imperative in facilitating temperature control and preventing avoidable bug infestations. 

How Powerful Should a Bathroom Fan Be?

Bathroom Vent Fan Lg
Bathroom exhaust fan

You require a bathroom fan that is strong enough to expel all the moisture from the space. Bathroom fans are rated on the amount of air that they expel per minute. The units of the measurement are cubic feet per minute (CFM). 

Ideally, a bathroom fan should remove at least 50 CFM while on an intermittent operation. The condition will apply to almost all bathroom fans. Nonetheless, it is imperative to consult the requirements of your locality to get the measurements right. 

Remember that you cannot afford to have a small CFM bathroom fan for a large bathroom room. It will be as good as being absent in terms of aeration. Hence, you might be wondering how to get the ideal bathroom fan capacity. 

All you require is to have the dimensions of your bathroom in square feet. The rule of thumb is that you need at least 1 CFM per square foot of the bathroom space. Hence, depending on the total square footage of your bathroom, you can estimate the ideal bathroom fan size. 

How to Maintain a Bathroom Fan Properly

You need to take good care of your bathroom fan to ensure that it is in optimal working condition. Taking care of it is also preventing frequent repairs that are time-consuming and expensive. 

First, ensure that you clean the fan regularly. The best way to clean is to disassemble the parts and individually clean them. You can also use a piece of cloth to extract the dirt lodged in parts of the fan. Regular cleaning is essential, and you should do it as often as you can. 

Also, be alert for the dysfunction of its motor. After some time, it will start producing some squeaking sound. A motor repair is not a common issue, and it may remain in top condition for up to 10 years. However, if it starts squeaking before this time, consider replacing it. 

Final Thoughts

In a nutshell, you’ll need a permit to install a bathroom fan. The requirements for being granted the permit will vary from one jurisdiction to the other. Hence, you should consult your local building department. 

You can install the bathroom fan yourself or employ an expert. If you make it a DIY project, you’ll have to obtain a permit first. On the other hand, hiring a contractor will save you the hassle of applying for a permit. 

We have also explained the code requirements for bathroom fans. They will vary from place to place. Hence, you need to consult the local authorities for codes that apply in your locality. Often the primary prerequisite is that you need to install a fan, especially if you don’t have windows. 

Lastly, we have elaborated on the advantages of having a bathroom fan. The above insights should equip you with an adequate guideline in the installation of a bathroom. 



Hubert Miles | Licensed Home Inspector, CMI, CPI

Hubert Miles is a licensed home inspector (RBI# 2556) with more than two decades of experience in inspection and construction. Since 2008, he has been serving South Carolina through his company, Patriot Home Inspections LLC. As a Certified Master Inspector, Hubert is dedicated to providing his expertise in home inspections, repairs, maintenance, and DIY projects.