In this guide

Bedroom Addition Cost per Square Foot

The average cost to add a bedroom addition is $200 a square foot. This figure can be slightly misleading because there are several types. Most think that additions mean a new structure added to their existing home, but you can also convert an existing area, such as an attic, garage, or basement. Both methods are valid ways of getting the space you need, but they have different attributes and price points.

Converting a space may be cheaper in some cases because you do not need to create a crawl space or slab foundation ¹ or worry about exterior finish work. However, there are additional issues to consider, and things like basement and attic conversions have their own costs. Most attics have costs of up to $400 a square foot to finish. This is because many require stairs and roofline ² modifications to incorporate the windows necessary for a bedroom. The attic’s position and need to add HVAC and deal with the ventilation mean this is the most expensive area to remodel, finish, or convert. While a new space addition has a total cost range of $150 to $250 a sq.ft. for bedrooms, conversions cost $80 to $400 a sq.ft., depending on the space.

Cost to Add a Bedroom by Type

Bedrooms contain different amenities, and people use them for various purposes. For that reason, the room you build may impact the total costs. Costs below are based on the average size of each room type. They could be different, depending on the room size and location.

Standard Bedroom Addition Cost

The cost of a regular bedroom addition is $11,520 to $57,000 for an existing space conversion. The costs for a new build addition are $21,600 to $36,000. This is for a room addition of 144 sq.ft., which is an average-sized bedroom for children, teenagers, or for gaining additional space. These costs assume the room has at least one full-sized window and a standard-sized closet. Rooms of this size can often be conversions from unused space. They measure roughly 12’ x 12’, so they can easily be carved out of basements, attics, and dining rooms.

Guest Bedroom Addition Cost

The average cost of a guest bedroom addition ranges from $18,000 to $90,000 for an existing space conversion. For a new build addition, the costs average $33,750 to $56,250. This assumes an average guest room size of 225 sq.ft. or 15’ x 15’. Many people adding a guest bedroom do so to allow guests to stay beyond a single night or two. For this reason, guest rooms are slightly larger to give the guest more room to spread out and feel at home. This addition size can often be done as a conversion or new space.

Cost to Add a Bedroom and Bathroom

The cost to add a bedroom and bathroom averages $20,000 to $80,000 for an existing space conversion. For a new build addition, the costs are $52,000 to $100,000. These costs assume a standard room size of between 144 and 150 sq.ft. They also assume the bathroom is a minimum 35 sq.ft. for a full bath. It could include bathrooms up to 90 sq.ft. to make this a Jack and Jill addition if there is another bedroom on the other side. Adding a bedroom and bathroom can be done to some existing spaces like attics and basements. It is more likely to be a new space addition as the size of the space grows.

Master Bedroom Addition Cost

The cost of a master bedroom addition is $24,000 to $120,000 for an existing space conversion. For a new build addition, the costs are $45,000 to $75,000. The average master bedroom is around 300 sq.ft. These prices are for the addition only and do not include the price of an ensuite bathroom. Master bedrooms are frequently added as conversions of existing spaces, such as lofts, attics, and garages. They can also be part of larger new space additions.

Average Cost of Adding a Master Bedroom and Bathroom

The cost of adding a master bedroom and bathroom averages $40,000 to $140,000 for an existing space conversion. For a new build addition, the costs range from $60,000 to $120,000. This assumes a combined bedroom and bathroom size ranging from 300 to 400 sq.ft. It is very common for master bedrooms to have a bathroom attached. This can be an existing space conversion in an attic or garage but may be a new space addition at these sizes. Typically, when approaching new additions of this size, conversions become less likely because they start to outstrip what space may be available.

Average Cost of a Master Suite Addition

The average cost of a master suite addition is $52,000 to $160,000 for an existing space conversion. The cost of a new build addition is between $100,000 and $200,000. Master suite additions typically start at around 400 sq.ft. but can be much larger. A master suite consists of a master bedroom, master bathroom, and other amenities like walk-in closets, dressing areas, and sitting areas. They also have common additions like fireplaces, balconies, and doors direct to the outdoors, increasing costs.

Average Cost to Add a Bedroom by Location

A new bedroom can be added to the home in many areas and ways. You can convert an existing space into a bedroom, such as an unused living room, attic, or basement. You can also build onto your home through a small bump out or full-scale addition. Each method has pros, cons, and other attributes to consider. Some conversions like living rooms into bedrooms are simple and do not take much effort. Other conversions like attics may be subject to additional building codes, making it more difficult. Full-scale additions also have considerations, including where you build out and how the new area connects with the home. Below are the average costs to add an average-sized room based on the location in your home.

Bedroom Bump Out Cost

The cost of a bedroom bump out is $4,000 to $9,000. A bump out is not a new room addition. Instead, it increases the size of your current space. So, you enlarge the room size in a bump out. This can be done to convert to a master bedroom, make space for a new walk-in closet, or make a small room into a much larger and more comfortable guest room. Bump outs can run the entire width of the room but rarely extend past 2 to 3 feet in depth. The average bump out size adds around 45 sq.ft. to an existing room.

Converting a Formal Living Room Into a Bedroom

The cost of converting a formal living room into a bedroom averages $10,000 to $15,000. Living room conversions are fairly simple and straightforward. Most living rooms already meet the legal definition of a bedroom. They are usually already the right size, have two means of egress, and have HVAC in place. It is customary in modern homes to add a closet, which is often expected at resale. Depending on how the living room is laid out, you may want to add walls or doors for privacy.

Cost to Convert a Garage to a Bedroom

The cost to convert a garage to a bedroom ranges from $10,000 to $20,000. Garage conversions can be very common types of additions. The cost range varies due to what may need to be done to your garage. Often, the doors must be removed and replaced with solid walls, insulation, and exterior siding. If the garage does not have a window currently, at least one must be added. HVAC must be extended if it has not been already, and the interior must be insulated and finished. 

Convert a Bathroom to a Bedroom

The cost to convert a bathroom to a bedroom is between $10,000 and $20,000. This is an uncommon conversion type because of the size. To be a legal bedroom, the space must have a minimum of 70 sq.ft. It also requires a window or second means of egress, and many bathrooms do not fit these parameters. If you have a bathroom that is large enough, you can convert it to a bedroom. It means tearing out everything down to the studs and capping off water and toilet waste pipes. The room can be refinished as a bedroom and a window added if necessary.

Convert a Loft to a Bedroom Cost

The cost of converting a loft to a bedroom averages $15,000 to $70,000. If your home has a loft, you may be able to convert it to a bedroom space. It must be at least 70 sq.ft. with ceilings of at least 7’ in height. For example, if it is 90 sq.ft. but only the center 10 sq.ft. have ceilings that are 7’ in height, the space cannot be converted. Conversion costs depend on things like if you need to add stairs, if the space needs an HVAC extension, and if you need to add walls or windows. Many lofts cannot be converted into legal bedrooms because of these logistics.

Cost to Add a Bedroom to a Basement

The cost to add a bedroom to a basement ranges from $20,000 to $30,000. Basement conversions have many considerations impacting the final costs. The space must be waterproofed before it can be finished. The basement often requires insulation as well. To be a legal bedroom, you must add a basement egress window or door, and the finished ceiling must be at least 7 feet in height. In some cases, the room floor must be lowered to do this.

Cost to Build a Bedroom Addition

The cost to build a bedroom addition is $40,000 to $60,000. This assumes a first-floor addition on a slab foundation. If you plan the addition on a second floor or want to extend your basement beneath the new addition, your costs can be much higher. In every addition, the exterior should be finished to match the home, including the siding and roofing. The interior should also flow with the home, having the same details like moldings and door styles. You also need to extend your HVAC to the new space or give it a separate HVAC system to be considered a bedroom.

Cost to Convert an Attic Into a Bedroom

The cost to convert an attic into a bedroom ranges from $50,000 to $90,000. Attic conversions create an extra room without adding to the home. Costs vary depending on if you need to add stairs, windows, or extend the HVAC to the area. Remember that only areas with a ceiling height of 7’ or above can be considered usable square footage. This often means the attic may not have much usable space for a bedroom, and sometimes, things like dormers may be added to increase the space. This can lead to higher prices than other conversions.

Cost to Add a Bedroom Above a Garage

The cost to add a bedroom above a garage averages $60,000 to $80,000. Adding a bedroom above an existing garage is essentially a second-story addition. The current garage roof must be removed, and the second story framed out above it. This means an entirely new roof must be added, along with new siding, stairs, HVAC for the area, and insulation in the garage to lower energy costs. Depending on the garage’s location, this can sometimes be connected to the main home, which has additional considerations and expenses. Other times, you may want to add an exterior staircase to the room above as an added egress.

Bedroom Addition Cost Breakdown

Additions, like most major projects, often involve multiple steps and professionals. Each addition has a set of costs, and even conversions may not have the same costs, depending on where they are. For example, a new build addition includes framing and a new roof, while most conversions do not. However, one conversion may require you to extend the HVAC, while another may have HVAC in place and does not require this. Bedroom additions with bathrooms may require plumbing, while additions without bathrooms do not.

Below are some of the average costs associated with a bedroom addition. Keep in mind that your project may not require all these, depending on its location and parameters.

Average Cost to Decorate a Bedroom

The average cost to decorate a bedroom ranges from $3,000 to $10,000, depending on several factors. Your costs are higher if you choose new furnishings, rugs, drapes, shelves, and accessories. However, they will be lower if you keep your existing furniture and only update soft furnishings.

Moreover, all types of bedroom furnishings have a range of prices based on style, material, and quality. You can purchase fewer items and spend more or purchase more things and spend less, depending on your goals.

Cost to Build a Closet in a Bedroom

The average cost to build a custom closet for a bedroom is $2,500 to $5,000. This closet is usually arranged for optimal organization. Closet size and how much organizational material you put into it can impact the total cost.

You can build a much less expensive smaller closet. Standard closets that contain only a clothing rod and are furnished with bypass doors can be built for $500 to $1,000. Therefore, the project cost depends on your closet’s size and type.

Cost of a Garage Addition With a Master Suite Above

The cost to build an attached garage with a finished space above it ranges from $60,000 to $65,000. Building an attached garage with a master suite above it is a great way to add more function and space to your home. Adding a garage is also a good way of adding value to your home, while the master suite above adds an additional bathroom and bedroom to the space. This can make your home more attractive when the time comes to sell and more functional and livable right now.

Bedroom Extension Cost

The average cost to extend a bedroom is $4,000 to $9,000. The most common method of extending a room is through a bump out. This extends the room’s width by roughly 2’. In most cases, the square footage gained by a bump out is around 45 sq.ft., which can often be enough to make a small bedroom feel much more comfortable or allow you to fit a larger bed into the space. A bump out can also take a room currently too small to be considered a bedroom and make it fit the legal definition of a bedroom by increasing the usable square footage.

Splitting One Bedroom Into Two

The average cost to split a single bedroom into two bedrooms falls between $4,000 and $6,500. This includes framing and drywalling ³ the new wall between the two rooms, putting up a small closet with bifold doors, wiring the new wall with outlets, and putting in a separate light source for one of the two rooms. If you want larger custom closets or more specialized lighting, your costs are higher.

Master Suite vs Master Bedroom

In many homes, it is common to have a master bedroom or bedroom larger than the others and designed for the home’s owner. This space becomes a master suite if you make it larger, add a master bathroom, sitting area, walk-in closet or closets, and other amenities, such as fireplaces.

In general, a master suite is larger than a master bedroom by a minimum of 100 sq.ft. The space is designed to be spacious and allow for more than sleeping or relaxing, but also a living area with seating and dressing areas. Adding a master suite is more expensive than a master bedroom, but adding a master suite also adds more space and function.

Enhancement and Improvement Costs

Radiant Flooring

All bedrooms must have some type of HVAC system installed. In cool climates, adding radiant floor heating ⁴ can be an alternative to extending your existing HVAC while making the room more comfortable. Radiant heat ranges around $10 to $25 a square foot.

Add a TV to a Bedroom

When adding a TV, consider wall-mounting it. Doing so can free up space in the room. It can also allow you to find the perfect position, regardless of where the furniture is placed. The average price to mount a TV is $100 to $300.

Fireplace

If you have a master suite, you may want to consider adding a fireplace. This adds warmth and ambiance to the room and provides a focal point. You can add many types of fireplaces, with a brick fireplace costing between $1,200 and $4,900.

Moldings

Additions should match the home inside and out. If the rest of your home has details like crown moldings ⁵, consider adding them to your room. Doing so can also add depth and interest to the space. Crown moldings typically cost $120 to $240 for one room.

Remodeling Terms Cheat Sheet

¹ Slab foundation: A layer of concrete, poured over a prepared surface of soil or gravel, that supports a house or other building structure

² Roofline: Construction material, typically composed of vinyl or aluminum, used to enclose the underside of eaves and ceilings

³ Drywalling: Type of plasterboard, commonly used to build walls and ceilings, composed of gypsum that is layered between sheets of heavy paper

⁴ Radiant floor heating: (Also known as Radiant floor) A heating system using tubes or electric wires installed underneath the flooring

⁵ Crown moldings: A decorative finish that adds interest to the area where the top of a window meets the wall, or lines the area where the wall meets the ceiling