How much does a 400 sq ft master suite addition cost?

400 square feet, or a 20x20 room, is the standard size for a master suite addition. So, a master suite 20x20 room addition cost ranges from $120,000 to $200,000 with the average being $150,000.

How Much Does It Cost to Add on A Master Suite

Before starting on a master suite addition to your home, it is important to understand the costs associated with this kind of project in order to budget accordingly. In this article, we will discuss the average cost of a master suite addition, the factors that can affect the cost, and how new tariffs can impact this.

Key Takeaways

The average cost of a master suite addition ranges from $120,000 to $200,000, with an average of $150,000
Factors that affect the cost include HVAC, windows, doors, flooring, closet organizers, lighting, and bathroom fixtures
While tariffs will affect the prices of construction materials, materials make up less than half of total costs, so it will not have a significant impact on the project as a whole

How Much Does It Cost to Add on a Master Suite?

A master suite includes a bedroom, bathroom, and closet, which means that the space has both dry and wet areas. The inclusion of a bathroom, a wet area, requires additional plumbing lines in your home, along with more fixtures than just a bedroom would need.

With this in mind, the addition of a master suite, at the standard size of 400 square feet, ranges in cost from $120,000 to $200,000 with the average being $150,000. Of course, if you choose a different size, then the price range will fluctuate, being either less expensive for a smaller size or more expensive for a larger size.

As well, this price range only reflects a single-story addition. For a second-story addition, meaning that another story to your home will be built, the cost will be significantly higher as a result of the need for structural support and stairs.

What Factors Affect the Average Cost of a Master Suite Addition?

Aside from the must-have construction materials out of your control, like framing, drywall, and insulation, as well as electrical wiring and plumbing upgrades, there are other factors that can affect the average cost of a master suite addition depending on your choices.

These factors include:

If your current system can’t be connected to the addition, then it will most likely have to be replaced with a newer, larger system.

While you will probably want to have windows that are the same or similar to the existing windows in your home for a cohesive design, the cost for windows could vary greatly based on the type you choose.

You will need interior doors and closet doors which can increase the cost of an addition depending on the type you choose. If you decide that you want exterior doors, such as patio or French doors, to lead outside from your new bedroom, this can also be more expensive.

The cost for flooring in the bedroom will vary based on whether you choose a cheaper option like vinyl or carpet, or go with a more expensive option like hardwood. Tile for the bathroom tends to be a more expensive option, no matter the style you choose, with prices ranging from $2 to $10 per square foot and more. Picking larger-sized tiles can help you save money as they are less labor-intensive to install.

You may want organizers for your closet. Whether it’s ready-made shelves inserted into the space or built into your closet, depending on the size of your closet, this could range from an additional cost of $1,500 to $10,000.

The lighting fixtures you choose will also vary greatly, but recessed lighting is a common choice at $150 to $200 per light installed.

From vanities and cabinets to faucets and shower hardware, bathroom fixtures will be more or less expensive based on if they are prefabricated or custom-made and if basic or high-end styles and finishes are chosen.

Before construction begins, you will need to secure proper building permits, which vary in cost depending on your local municipality. Additionally, hiring an architect or designer to create plans for the addition will add to your budget.

How Might Tariffs Affect the Cost of a Master Suite Addition?

With a large part of construction materials like lumber, drywall, lighting, and flooring coming from Canada, Mexico, and China, it’s understandable that you may be concerned about how the tariffs placed on these countries affect the cost of a master suite addition.

It’s important to note, though, that when it comes to construction costs, materials make up less than half of the total. This means that even with an increase in price due to tariffs, your overall budget will only be impacted slightly, so in the long run, your plans and the cost to construct an addition will not be derailed.

Final Thoughts

Throughout this article, we have discussed the cost of a master suite addition, factors within master bedroom addition ideas that can affect the cost, as well as how tariffs may impact your project. At Top Home Builders, we are committed to providing you with exceptional home additions. Contact us today to receive a free estimate!

Related Article: Top Luxury Features for Homes in 2025

FAQs

400 square feet, or a 20×20 room, is the standard size for a master suite addition. So, a master suite 20×20 room addition cost ranges from $120,000 to $200,000 with the average being $150,000.

It’s good to begin by understanding average costs and using that to figure out your budget. Then, talk to contractors and architects about your ideas for the space; they can help with the design and provide you with a cost estimate before moving forward with construction.

A standard master suite addition is 20×20, or 400 square feet, in size. While your suite can be sized differently, this is a good starting point when determining how much space you have for an addition. Figure out what the requirements in your city are for property setbacks in your yard. If you think there’s enough space in your yard, consult with a contractor who can come to your house and provide a detailed measurement.