Do you need Soffit Vents in a Garage? Everything you need to know

Attic ventilation is a topic that gets a lot of attention. It has been like that for a long time because there are many different opinions circulating out there. It’s even more complicated when it relates to the garage. So, in this post, you will learn about the soffit vent and whether you should install some for your garage. Let’s get into it.

Attic vents are not a requirement, according to the IRC. However, if you insulate the attic floor or the ceiling of your garage, it will be required by code to vent the attic by installing soffit vents, ridge vents, gable vent, or a combination of them. If you install only soffit vents, the standard requirement is 1 square foot of ventilation per 150 square feet of attic floor space.

We will look at instances where you need to install soffit vents for your garage and instances where you don’t need to. Later in the article, we will discuss how to make soffit vents effective for your garage.

 But before then, let’s talk about soffit vents briefly so that we are on the same page.

What are soffit vents, and why are they important?

Just as the name depicts, these are vents installed in the roof soffit. They are very helpful for a couple of reasons. Let me explain.

The attic is a space that traps a lot of hot and humid air when unvented. In the winter, warm, humid air from your living space gets transferred to the attic through air leaks and vapor diffusion. The moisture, now in the attic, condenses back into a liquid. 

Over time, when the moisture builds up in the attic can cause a lot of issues. Firstly, it will cause mold growth in the attic, and that leads to the attic’s musty smell some of you are familiar with. Secondly, all that moisture can cause the woods in the attic to rot. These damages can be very expensive to repair when you eventually notice. 

In the summer, a lot of heat is transferred from the roof into the attic. And all that heat can seep into your home or garage when the attic floor is uninsulated. This can instantly make your garage extremely hot and unbearable to be in. If you use an A/C unit in your garage, your cooling cost will increase drastically.

However, when you install a soffit vent under the roof eaves, it will allow fresh air from outside to blow into the attic and replace all that warm, humid air. This means there will be no moisture buildup in the roof, and no heat is transferred to your home.

There are two types of soffit vents available today — continuous soffit vents and individual soffit vents. Continuous soffit vents are the type that spans across the entire soffit. This allows the most air into the attic. They are increasingly becoming popular as new homes are choosing it over the individual soffit vents.

The individual soffit vents, however, have been the go-to soffit vents for a long time. And they can be added together to look just like a continuous soffit vent.

Why you don’t need soffit vents in a garage

Now that we’ve got the basics covered let’s discuss the instances where it’s unnecessary to install soffit vents for your garage.

The garage is a utility room.

As we all know, the primary use of the garage is to store our vehicles. And for this reason, the garage is treated differently from our living spaces. Most garages have no windows or vents, and barely any insulation at all.

That is because the building codes don’t make it a requirement. According to the code, the garage is considered a utility room. Utility rooms don’t require any ventilation. It’s simply a choice of the builder whether to include it or not.

In essence, if you use your garage as a utility room, park your vehicles, and store tools and rarely used equipment in there, you don’t need soffit vents or any other vents. The natural air that blows into the garage when you open the garage door should be enough ventilation for the garage.

The garage is not part of the HVAC system.

Garages with no ventilation can be extremely hot in the summer and freezing in the winter. That’s because heat is transferred from the attic into the garage in the summer, and the cold air in the attic during the winter is transferred to the garage. 

All the temperature swings in the garage will, however, do not affect your electricity bills. That is because the garage is not included in the heating, ventilation, and air-conditioning systems of most homes. 

The garage is also thermally separated from our living area with insulation. This means no hot or cold air can be transferred through the walls into your living area, bringing extra work on your heating and cooling systems.

3 Reasons Why You Need Soffit Vents in the Garage.

All that we have discussed is true. If you simply park your car in the garage and don’t spend so much time there, there is no need to vent the garage. This is not to say soffit vents for the garage are a complete waste. There are still excellent reasons why you should install soffit vents in the garage. Let’s take a look at them.

1. It is required when the attic floor is insulated.

If you have plans to insulate your garage ceiling or attic floor or if it is already insulated, it is required by code that you vent the garage roof. 

The standard requirement is, for every 300 square foot of attic floor, there needs to be at least 1 square foot of free net ventilation. That is, assuming there are 50% soffit vents, and 50% ridge or roof vent. However, if you are venting the garage with only soffit vents, it is required that for every 150 square feet of the attic floor, there has to be a 1 square foot of ventilation. 

This is a requirement by the International Building Code. You may get into trouble when a building inspector comes to your home for inspection and realizes you didn’t do the right thing.

2. If you are converting your garage into a living space

If you have plans of converting the garage into a workshop, an office, a living room, installing soffit vents is an excellent idea. That’s because you are going to spend a lot of time in the garage if you convert it into a living space. So, you want the temperature conditions there to be ideal.

As I mentioned in the previous section, an unvented garage roof can make your garage very hot in the summer and extremely cold in the winter. These extreme temperatures can be uncomfortable to be in for a long period. 

Installing soffit vents and properly directing the wind with baffles will help keep the roof cool and keep your garage at an ideal temperature. This also ties into my next point.

3. It reduces garage heating and cooling costs

If you are part of the few homeowners that have their garage included in your home’s HVAC system, then it’s important to install ventilation in the form of soffit vents, gable vents, or ridge vents. 

Doing so will reduce the heat transferred from the roof into the garage. This means your garage’s electricity bills on cooling will reduce. 

How to Make Soffit Vents Effective: Install Attic Baffles

Suppose you have decided to install soffit vents for your garage, excellent. But here is one important thing you need to know. And that is

To ensure proper airflow from your soffit vents to the attic, you need to install attic baffles. 

But what is an attic baffle?

Attic baffles, also known as rafter vents or venting chutes, help properly channel the air from your soffit area into the attic to ensure proper airflow. They are installed in between the roof rafters or underneath the roof sheath.

One other thing they are good at is to block any debris and moisture coming through the soffit vent from outside into the attic. 

The AccuVent PVC Attic Baffle (on Amazon) is excellent, and I highly recommend them. It will improve air circulation in the attic and block moisture and debris, keeping your attic cool and dry at all times.


If you use your garage simply to store your vehicles and a few other equipment pieces, adding soffit vents to the garage might be unnecessary. However, if you decide to insulate the garage’s attic floor or garage ceiling, it’s a must to vent the garage roof with a soffit vent, ridge vent, or a gable vent. It’s also an excellent idea to add soffit vents if you are converting your garage into a workspace or living area. 

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