Room Addition Costs by the Square Foot 12×12 Versus 20×20

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If you are considering a room addition, it’s essential to plan ahead and have a realistic budget and scope in mind. It’s important to compare costs of room additions, by square footage and needs.While an addition may be high, however thpotential value it will add to ensure the project is a good financial decision.

Home Addition Cost Per Square Foot

Home additions cost between $86 and $208 per square foot. The average cost is $128 per square foot. The cost variance is based on the quality of the new addition to the house.

A basic addition costs around $86 per square foot. A mid-level home addition costs, on average, $128. A luxury home addition is around $208 per square foot.

A basic addition might be a simple room with electrical wiring and no plumbing. More complex rooms such as bedrooms and bathrooms with luxury finishes and light fixtures will cost more. Kitchens are very pricey, with top-tier appliances and significant electrical needs that can cost up to $400 per square foot or higher.

Home Addition Cost Calculator

Here are some calculation ranges based on the per square foot pricing for basic to luxury home additions.

Room Addition Cost Calculator

Using the $128 average cost per square foot for a home addition, you can calculate the cost to add a room to a house.

Room Addition Cost Chart

When increasing your square footage, you can build a second story to your home, or you can build out with a bump-out to increase your square footage. When making significant changes to the structure of your home, work with an architect and general contractor to ensure you make a sound decision in your choices when adding a home addition.

Adding A Room to A House

For an exact price, you will need to have accurate measurements of the square footage of the addition and details on the pricing of all that will be built into the home addition.

Bedroom Costs

$10,300 – $24,900

Master Bedroom Costs

$59,400 – $96,500

Bathroom Costs

$18,000 – $47,000

Sunroom Costs

$8,100 – $30,000

Family Room Costs

$34,400 – $83,200

Kitchen Costs

$25,100 – $43,400

Second Story Costs

$100,000 – $350,000

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Cost To Add a Second Story

When adding a second story to a home, the cost will be between $100 and $300 per square foot. Second-story additions can be expensive because you must build the second-story addition with the exact needs as building a home from the ground up with plumbing, electrical wiring, framing, and additional features.

Bump-Out Addition Cost

Bump out additions cost between $5,000 to $30,000. Bump-out additions add on to an existing room of a house and are not as expensive as adding a second story or an entirely new room. They allow you to expand the square footage of your home as a home addition.

Some common bump-outs include adding square footage to a kitchen, even as small as two feet, in order to add a kitchen island or other features.

Cost Factors to Expand a House

There are several cost factors to consider when adding a home addition to a house. Construction costs could be very high and vary. Here are some averages construction costs when adding a new room to your house, such as a bedroom or bathroom,

Construction Cost Factors

Here are several construction-related costs.

• Permits can cost between $100 to $300 each.
• Architects can charge between $100 to $250 per hour
• Preparation of the site, including excavation and demolition, can cost between $1,500 and $3,000.
• Pouring concrete and foundation can cost around $113 to $126 per cubic yard.
• Roofing can cost between $7 to $10 per square foot and is based on materials that are used.
• Insulation that is blown in can cost close to $3 per square foot.
• Siding installation can cost up to $8 per square foot.
• Drywall can cost $2 per square foot

Additional components of the house will have varied costs and include:

• Windows
• Flooring
• Plumbing
• Electrical
• HVAC and Ductwork
• Crown Molding
• Landscaping
• Final Cleanup

Should You Add-On or Build-Up?

It is usually much cheaper to build out a home addition than to build up. Usually, when building up, the foundation on the first floor is not strong enough to withstand the load of a second story. Significant costs associated with strengthening the foundation and walls can exist.

Build Up – In some cases, you may not be able to build out. Examples include if your home is close to a property line. In this case, it would be less expensive to add a second story if built above a garage. Garages can handle the weight of a second story better than the rest of the foundation on the house.

Build Out – Building out can also be costly, as you have to lay a new foundation. Comparing costs to build up versus building down should be considered before making a decision to add an addition to a home.

Permits and Restrictions – Adding a room to a house can cost around $200 to $600. Often, building up requires more permits than building out. You will benefit from using a contractor to help you obtain the needed permits.

Planning Your House Addition

Home additions are significant projects that require several skilled trades such as architects, engineers, and general contractors to be completed properly.

Home Addition Plans

For the architectural plans and blueprints for your addition, you could pay between $1,000 and $3,000. Architects are trained in understanding and generating the best ideas to add an addition to your home that will connect and flow with the rest of your home. They can seamlessly make all of the home flow together. They are trained in design and engineering and have the know-how to deal with complex design and structural issues.

Ensure your architect and general contractor are in agreement on the construction plans and plans for the addition. The contractor will charge more if the plans are not well created and not communicated well to them.

Agree on Price and Payment Schedules

Ensure you have a good agreement and contract with your general contractor before you start building the addition on your house. Reviewing the contract line by line with your GC will help you understand what they will do when constructing the addition.

You will need to put down a downpayment on construction services and pay along with the way for the rest at certain milestones in the project. The contract with the general contractor will outline all of the details and the payment schedule. For example, payment may be due after framing is completed on the addition.

Also, it is very common for construction delays to occur. Once construction starts, the general contractor could find things behind walls or under floors as they start demolition. Also, delays can occur due to material back order and other issues. Plan contingency timing into your contract for your home addition.

How Can You Save Money?

There are many ways you can save money when preparing for a home addition.

• Prepare the site for construction. Make sure the space is easily accessible. Move landscaping and clutter. This way, you do not have to pay for someone else to do this service.
• Start your own demolition. Tear down walls and haul away debris.
• Use existing materials contractors have leftover from other jobs instead of procuring new materials. Contractors often have leftover materials that could cost you much less to use than having to source materials from an unknown source. This does not work if you are building a luxury custom addition.
• Ensure you clean up around the construction site every day. Clean your countertops, cabinets, flooring, etc., to keep debris from drying on to them. Construction companies can charge up to $200 per day to do the cleanup you can usually do yourself.
• Haul away the debris from construction on your own. There is always debris associated with construction projects on new home additions. This can come from lumber scraps from taking out old cabinets or old bathroom fixtures and vanities. Another idea is to reuse old cabinets in the garage of your house rather than demolishing them.
• Deliveries will come from the lumber yard and manufacturers to your house for the construction of the house addition. Make yourself available to your contractor to pick up the materials instead of having them delivered. This will save on delivery costs.
• Complete the finish work on your own. This might include painting walls and sanding woodwork.

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Frequently Asked Questions

How much does it cost to add 100 square feet to a house?

The average cost to add 100 square feet to a house is $12,800. On the low end, the price is $8,600 and $20,800 on the high end.

How many square feet are in a 12×12 room?

There are 144 square feet in a 12×12 room.

How much does it cost to add on a 12×12 room?

The average cost to build a 12×12 room is $18,432 at $128 per square foot.

How many square feet are in a 20×20 room?

A 20×20 room is 400 square feet.

How much does it cost to add on a 20×20 room?

The average cost to build a 20×20 room is $51,200.

Is it cheaper to build up or out?

It is cheaper to build out. This is because the construction and labor costs are less expensive. When you build upward, you must pay for more materials, labor, a structural engineer, and many more permits.

How significant can a bump-out addition be?

Bump-outs are minor additions to homes to increase the square footage. It is smaller than an addition that consists of multiple rooms. Most bump-outs can be just a few feet up to as big as a single room.

How long does it take to add a room to a house?

It will take three to four months to add a room to a house as an addition.

How do you calculate the cost of an extension?

You need to determine the square footage of the extension and estimated costs per square foot, then multiply the two. The price per square foot will be based on the quality of materials and labor needed to build the addition.

How do you add a room to a house cheaply?

There are many ways to add an addition cheaply to a house. Some examples include finishing out a basement, converting an attic into a room, finishing out a garage, and adding a sunroom.

Summary

You can calculate the costs of your home addition based on the price per square foot and the desired size of your new addition. Consider a bump-out if you are on a budget. Also, ensure you work with licensed professionals who can help you decide the best type of addition for your home and financial situation.