What Is The Cost Of A Home Addition In Millbrae?

For more than 40 years we’re building a better future for families in Pacifica, CA

A beautiful living room and outside living space

Are you thinking about adding a home addition to your Millbrae house? Are you wondering what the cost of a home addition is? Are you looking for home addition ideas to maximize your space?

Whether you’re looking for an extra bedroom, bathroom, kitchen, or even a home theater, there are many options available when it comes to adding an addition to your home. But one of the most important things to consider is the cost of adding an addition.

In this article, we’ll discuss the average cost of a home addition, as well as factors that affect the cost and ways you can save on the project. By the end of this article, you will understand the costs of various types of home additions so you can make an informed choice. Let’s get started! 

What Is The Cost Of A Home Addition?

Adding a home addition is an exciting project that can bring more space and value to your home. But before jumping into the process, you need to know how much it will cost. 

Let’s start by looking at the average cost of a home addition, as well as the typical cost range for a home addition.

Average cost

Nationwide, the average cost of a home addition is about $50,000, according to Angi. (All pricing data sourced from Angi unless otherwise stated.) That being said, there are a couple of caveats to keep in mind with this figure.

First, the size, the scope of the project, and the material quality can drastically change the home addition cost.

Second, it should be noted that although the average cost of a home addition figure cited above includes everything from small projects with low-end materials to major building projects with high-end materials, it is naturally slanted towards cheaper projects since those are the types of projects most commonly done.

Third, the quality of work is not addressed in the average home addition cost. In other words, you get what you pay for when it comes to labor and the quality of work. Here at Home Pride Construction, we are committed to delivering the highest-quality design, craftsmanship, and customer experience. You can learn more about our home addition service in Millbrae, CA, here.

Typical cost range

Keeping those caveats in mind, the typical cost range for home additions goes from about $22,00 to $81,000.

Factors That Affect The Cost Of A Home Addition

A home addition under construction with wood rafters visible

There are a number of factors that can affect the cost of a home addition, and we’ll touch on some of the most important ones below. Read on to learn more.

Size And Scope

One of the most important factors affecting the cost of a home addition is its size and scope. Obviously, a larger addition with more square footage is going to cost more than a smaller one. But it’s not just square footage that you need to consider–the type of room you’re adding and its intended purpose will also play a role in determining the price. For example, adding an extra bedroom is going to be less expensive than adding a luxurious master suite complete with a walk-in closet and en-suite bathroom. 


Another big factor in the cost of a home addition is who you hire to do the work. If you choose to go with a reputable contractor such as Home Pride Construction, who has experience building additions, you can expect to pay more than if you try to DIY or hire an inexperienced contractor. But in most cases, it’s worth it to pay for quality workmanship. After all, this is your home we’re talking about! 


Depending on the size and scope of your project, you may need to hire an architect to help with the design. This will obviously add to the overall cost of the project. However, in many cases, an architect can save you money by helping you avoid costly mistakes during construction. 

A general contractor will typically charge less than an architect or designer, but they may not have the same level of experience or expertise. If you’re planning a large or complex home addition, it’s worth it to invest in an architect who can ensure that the job is done right. Per Angi, an architect’s fee can range anywhere from 5% to 20% of the total project cost.


The materials you use for your home addition will also affect its overall cost. For example, using high-end materials like marble or granite for your countertops will obviously be more expensive than using laminate or tile. Similarly, if you’re planning on adding any custom features or finishes, those will also drive up the cost of your project. 


The location of your home can also influence the cost of your home addition. If you live in an urban area where land is at a premium, building an addition is going to be more expensive than if you live in a rural area. If your home is located in a historic district or protected area, there may be special regulations that apply to any changes or additions made to your property–and those regulations can come with a hefty price tag. 


Another major factor affecting the cost of a home addition is labor costs. If you live in an area with a high cost of living, you can expect to pay more for labor than if you live in an area with a lower cost of living. And if your project requires any specialized trade skills or training (like electrical work or plumbing), those workers will charge more for their services as well. 


In most cases, you’ll need to get building permits for your home addition from your local government office before starting construction. The cost of these permits will vary depending on where you live and the size and scope of your project. Generally speaking, the cost of building permits can be as low as $150 or as high as $7,500.

Site Prep

Before construction can begin on your home addition, the site needs to be prepared. This usually involves clearing away any existing structures (like sheds or decks) and leveling out the ground where the new addition will go. The cost of site prep varies depending on how much work needs to be done, but it typically ranges from $1,500 to as high as $10,000.


Once construction is complete, there will be some cleanup required before you can start using your new space. This includes things like removing construction debris and hauling it off to the dumpster. The cost of cleanup varies depending on how much debris there is and how much disposal or hauling is required.

Home Addition Cost By Type

New modern screened porch with patio furniture, summertime woods in the background

How much does a home addition cost? The answer, of course, depends on the type of addition you’re looking to add. Here’s a quick rundown of the average cost range of some of the most popular types of home additions.

Basic Living Room Or Family Room

On average, building a basic living room or family room will cost anywhere from $17,300-$43,200. This type of project generally involves adding square footage by constructing walls, ceilings, flooring, and windows. It also typically includes electrical work, insulation, and drywall installation. If you are looking for something slightly more luxurious, such as built-in entertainment centers or custom cabinetry, you may need to pay more for your project. 


Adding a bedroom to your home typically costs around $8,600-$21,600. This includes the same types of construction projects as with a basic living room or family room (walls, ceilings, flooring, and windows). However, for a bedroom with all the amenities–such as a closet with shelving and bathroom fixtures such as sinks, tubs, and showers–your total costs could be higher than $100,000.


Kitchen renovations are often one of the most expensive kinds of projects because they involve so many different elements that need to work together seamlessly in order for them all to function properly. Installing a kitchen can cost anywhere from $48,000-$95,000, depending on the size and complexity of the project. This would include adding new cabinets and countertops, installing new appliances, reworking existing electrical wiring, installing plumbing fixtures, and possibly replacing flooring.


Building a sunroom is another popular option when it comes to home additions. The average cost for this type of project is between $16,135-$70,000, depending on the size and features desired. The type of flooring, insulation levels, and window style and number can all have a major impact on the price. On the other hand, sunrooms are usually constructed using wood framing techniques which makes them relatively easy to install compared to other types of additions, such as second stories or modular builds where steel frames are needed.

Laundry Room

A laundry room can cost as low as $2,000 for a closet-sized laundry room or as high as almost $15,000 for a larger laundry room, according to Home Advisor.

Home Theater

If you want a soundproofed home theater room, this type of space usually costs within the $20,000-$70,000 price range, per Bob Vila.


A very basic bathroom will cost in the $6,200 to $15,500 range. However, similar to kitchens, plumbing and electrical costs can easily push the price over $100,000.

Second Story

Second story addition framing constructed by Home Pride

A partial second story averages around $80,000-$250,000. However, a full-fledged second-story addition could cost between $100,000-$600,000. You can learn more about second-story additions here.


Per Home Advisor, a garage addition can run you anywhere from $25,000 to $50,000. A lot of the cost depends on whether you require electric or HVAC work and whether it is a detached garage or attached to the main house.

Front Porch

A front porch typically costs between $4,600 to $22,200, depending on the complexity of the design.

In-Law Suite

If the in-law suite is a simple bedroom, it will cost around $8,600-$21,600. On the other hand, a detached in-law suite could easily cost $100,000 or more.


Per Home Advisor, a bump-out has a wide cost range of $1,700-$18,900, primarily based on the size of the bump-out.


Mudrooms are functional entrance rooms where everyone takes off their shoes or hangs up their coat after a long day out. They range in cost from $8,000 to $16,000, according to Home Advisor.


The cost of a balcony addition ranges from approximately $5,000 to $10,000 per Home Advisor.

Modular Addition

Constructing a modular or prefabricated room will typically cost in the range of $20,000-$30,000, according to Home Advisor.


Expanding the footprint of a second story can be achieved by cantilevering the upper level. This involves installing sturdy joists or beams on the exterior of your home in order to extend beyond the existing foundation of the first floor. On average, this will cost you between $15,000-$25,000, according to Bob Vila.

Home Addition Benefits

House with sunroom

Investing in a home addition can be a great decision. Here are some of the benefits associated with home additions.

Increased Property Value

One of the most obvious benefits of adding to your home is that it increases its market value. This makes investing in a home addition an incredibly smart decision from both a financial and practical standpoint. 

Additional Living Space

Building an extra bedroom or bathroom can provide much-needed breathing room for growing families or those who frequently entertain guests. Having extra living space can make all the difference for those times when unexpected guests come by or when you just need some extra room to relax at the end of a long day. 

More Storage Space

Home additions are also great for creating additional storage space. For those who find themselves running out of places to store items, adding another room could be just the solution they need. Not only does this give them more room for their belongings, but it also keeps their house looking neat and tidy by providing additional places to store items away from sight. 

Alternative To Moving

A home addition can provide you with more space without having to go through the hassle and expense of moving to a new home. This can be especially important if you have children who prefer to stay in their current school or if you want to maintain your current work commute. With a home addition, homeowners can enjoy all the comforts of their current house without having to uproot themselves and start anew somewhere else. 

How To Save On The Cost Of A Home Addition

Woman use calculator calculates expenses

If you plan to add a home addition or extra room, it is important to be mindful of your budget and cost. Thankfully, there are a few cost-saving strategies you can use when taking on a home addition project.

  • While we recommend leaving complex work to the pros, you can DIY smaller tasks, such as painting a room, to save yourself some money
  • If possible, look for ways to reuse existing components like flooring or wall studs instead of purchasing new building materials
  • Courteously negotiate with contractors–a good contractor should be willing to work with you to come up with the best job possible within your budget
  • Budgeting for an extra 10-20% for contingencies can save worries in the long run.

How To Pay For The Cost Of A Home Addition

Paying for a home addition can easily cost thousands of dollars, depending on the size of the project and the materials used. So it’s crucial to start out by researching your payment options. Here are a few common options.

Financing Via The Contractor

Many contractors offer financing options so you can make payments over a period of time.

Home Equity Line of Credit (HELOC)

If you’ve already built up equity in your home, you may be able to get a HELOC or home equity line of credit. This is basically a second mortgage that allows you to borrow against the equity in your home.

Personal Loan

Personal loans typically have fixed interest rates, which can make them easier to budget for than HELOCs. However, you may need good credit to qualify for the best rates on a personal loan.

Credit Cards

If you have good credit, you may be able to finance your home addition with a credit card.

Home Addition Cost: DIY vs Hiring A Pro

When considering the cost of a home addition, it can be difficult to measure the cost between doing it yourself (DIY) and hiring a professional. DIYers looking to save money usually don’t consider the cost of tools and materials, as well as the time needed for research and experience–assuming they aren’t contractors themselves.

On the other hand, reputable contractors don’t skimp on materials or quality installations. In other words, professionally installed home additions hold their value better over time due to superior construction skills. Decide what is more important: cost savings now or greater cost savings over time.

Questions To Ask When Planning A Home Addition

Progress of a laundry room remodel from framing through cabinets & flooring

What’s Your Budget? 

The biggest question you need to ask yourself is how much you want to spend on this project. The cost of a home addition depends on a variety of factors, such as size, materials, and labor costs. Once you have an idea of your budget, you will be able to narrow down what kind of addition you want and how big it should be. 

What’s The Purpose Of The Addition? 

Are you looking for additional space for a bedroom or office? Do you want an outdoor patio for entertaining guests? Knowing the purpose of the addition will help you plan what type of structure it should be, as well as the materials needed for construction. 

Do You Need Permits Or Approvals?

Before embarking on any construction project, make sure that all necessary permits have been acquired. Depending on where you live, there may be local zoning laws that dictate what type of additions are allowed in certain areas, as well as height restrictions and other regulations. If these requirements aren’t met, then your construction project could potentially face delays or even fines from the city.            

Do You Have The Necessary Skills For Construction? 

While hiring a professional general contractor is always recommended for any large-scale project, such as home additions, there are still plenty of smaller tasks that can require specialized skill sets, such as plumbing or electrical work. If these tasks need to be completed by someone other than the contractor, make sure that they are qualified and knowledgeable.

Home Pride Construction Can Bring Your Dream Home Addition To Life

Home additions can be a great way to add value to your property and expand your living space. However, it’s important to understand the cost of a home addition before getting started. If you’re considering a home addition, we’d be happy to help! Give us a call or fill out our contact form today and let’s get started on making your dream home a reality.