Home Additions

How much does a Home Addition cost at Custom Built?

Want to find out how much it costs to have Custom Built do your home addition? Click here to learn about what goes into pricing a home addition project.


How much does a home addition cost at Custom Built?

Getting prices for your home addition can be confusing and time-consuming. Especially when different home remodelers give you wildly different prices after taking up your precious time dissecting your project. Fortunately for you, we have you covered.

A typical first-floor 20’ x 24’ home addition starts at around $96,000 for a three-season room. (Sunroom for example)

A first-floor 20’ x 24’ bedroom with a primary bathroom installed with the highest quality fixtures can top out at around $350,000.

As a Lansing, Michigan-based home remodeling company, we have extensive experience pricing, designing, and building home additions of all shapes and sizes. We want to provide you with accurate information that makes planning your projects easier.

In this article, you will learn what factors will influence a home addition’s price, the price ranges and what to expect from different types of first-floor home additions available for the size 20’ x 24’.

Exterior view of home addition with deck and patio door

Factors that will influence the cost

When it comes to home additions, a variety of factors will affect the price. These factors include,

Size of the home addition

This will have a large influence on the overall price of the home addition project. A larger-sized addition will require more materials, labor, and building time to complete the remodel.

3 season vs 4 season home addition

When planning for a home addition, you will need to decide if you want a 3-season room or a 4-season room.

The main difference between them is that the 4 season room can be used year-round. The 3-season room does not have central heating and can only be used during the warmer months.

Due to the building code requirements, a 4-season home addition will be more expensive to build than a 3-season home addition. You’ll see the exact pricing difference between them in the next section.

Existing home condition

The addition must attach to the existing home as seamlessly as possible. Due to this, the condition of the existing home will influence the cost of a home addition. This could include

  • Age of the home 

  • Condition of the home’s exterior walls 

  • Condition of the roof and the connection point between the new and existing roof

  • Matching existing home siding, for example
  • Plumbing, electrical, and HVAC systems
    • What condition are they in?
    • Will they need to be upgraded?
      • New electrical panel
      • Cast iron waste lines
      • Will the current furnace and AC be able to properly heat and cool another 480 Sqft

  • Is the current basement finished?
    • In order to get new Electrical, HVAC, and plumbing to the addition, it will cost more to tear out existing ceilings to allow us to get mechanical to the new room. 

These are all factors for the existing home that will have an effect on the price of a home addition

Type of home addition

In many cases, a homeowner will add another bedroom, bathroom, or living space on the main level of their home.

For the home additions types that require more plumbing and electrical components, (i.e.. bathroom, kitchen, laundry, etc.) This will have a greater impact on the price than a room with no required plumbing (i.e.. living room, bedroom, sunroom).

The Price for different types of home additions

There are many different options available to homeowners for a home addition. Each project is custom and priced accordingly.

It should be noted that the examples provided are for a first-floor home addition added onto the side of an existing home. 

It is possible to add space onto the second story of a home, such as above a garage. Similar pricing factors are taken into consideration when pricing a second-story home addition such as existing structure condition, roofing, electrical, HVAC, and plumbing.

1. Basic 3-season home addition

For a basic 3-season home addition, the price ranges from $96,000 - $140,000

This range accounts for the variations in a home addition such as flooring, tie-ins to the existing roof, siding options, window options, and patio door options.

2. Basic 4-season home addition

For a basic 4-season home addition, the price ranges from $150,000 - $200,000

You may be thinking, “Woah, that’s a massive difference between the 3-season and 4-season”

As stated in the pricing factors section, this is a massive influence on price. A 4-season home addition has much more building code requirements than a 3-season home addition.

This includes insulation, electrical, plumbing, HVAC, crawl space, and framing requirements. 

These all account for the major difference in price between the 3 and 4-season home addition. 

For the 4-season home addition price range, the same principles apply as the 3-season. The many options available, such as flooring and siding, account for the range in price.

3. 4-season home addition with a kitchen

For a 4-season home addition with a kitchen, the price ranges from $220,000 - $350,000

The variance in price range now has to take into account the plumbing and electrical components of the new structure and how they connect to the existing home. 

It also has to take into account the many options available for a kitchen remodel such as fixtures, cabinets, appliances, layout, and size.

4. 4-season bedroom with a primary bathroom

For a 4-season bedroom with a primary bathroom, the price ranges from $220,000 - $340,000

For this home addition, similar plumbing, electrical, and mechanical questions must be addressed as with the kitchen. 

The bathroom also has a range in the quality of shower options, cabinets, sinks, faucets, and lighting fixtures.

Are you ready for a custom-built home addition?

We have shed some light on home addition pricing. As you have read, many factors that influence the cost of a home addition project. At Custom Built, we believe in openness and transparency. You now know what to expect to pay for your home addition.

Ready to move forward with a home addition project or have some more questions about the remodeling process? Great! Feel free to connect with our sales staff and they will be more than happy to speak with you about your remodeling project.

If you’re not yet ready to begin the remodeling process, you may want to learn about how to plan your home addition project or how to find the right remodeling contractor for your project.

Similar posts