Home Addition Cost Calculator
12×14 ft room addition — 168 sq ft
Estimated Total Cost
$20,160 – $28,560
$120.00 – $170.00 per sq ft
Material Cost (40%)
$8,064 – $11,424
Labor Cost (60%)
$12,096 – $17,136
Addition Size
168 sq ft
Cost per Sq Ft
$120.00 – $170.00
Permit Reminder: Home additions almost always require building permits ($500–$2,000+). Permit costs, architectural plans, and engineering fees are not included in this estimate. Contact your local building department before starting work.
Disclaimer: Estimates are for budgeting purposes only. Actual costs vary by location, contractor, material availability, and project complexity. Always get professional quotes for exact pricing.
Home Addition Cost Breakdown
| Addition Type | Basic / Sq Ft | Mid-Range / Sq Ft | High-End / Sq Ft |
|---|---|---|---|
| Room Addition | $80 – $120 | $120 – $170 | $170 – $250 |
| Bathroom Addition | $150 – $220 | $220 – $300 | $300 – $450 |
| Sunroom | $100 – $150 | $150 – $220 | $220 – $350 |
| Second Story Addition | $150 – $220 | $220 – $300 | $300 – $450 |
| Garage Addition | $50 – $80 | $80 – $120 | $120 – $200 |
Average Project Costs (Mid-Range Finish)
| Project | Typical Size | Material (40%) | Estimated Total |
|---|---|---|---|
| Extra Bedroom | 12 × 14 ft (168 sq ft) | $8,064 – $11,424 | $20,160 – $28,560 |
| Bathroom Addition | 8 × 10 ft (80 sq ft) | $7,040 – $9,600 | $17,600 – $24,000 |
| Sunroom | 12 × 16 ft (192 sq ft) | $11,520 – $16,896 | $28,800 – $42,240 |
| Master Suite | 16 × 20 ft (320 sq ft) | $21,760 – $32,000 | $54,400 – $80,000 |
How We Calculate
Our home addition cost calculator estimates project costs using square footage, addition type, and finish level to determine a total cost range. We apply regional cost-per-square-foot data and split the total into material (40%) and labor (60%) components.
How the math works: We multiply total square footage by the cost-per-square-foot range for your selected addition type and finish level. The material/labor split of 40/60 reflects industry averages where labor (framing, electrical, plumbing, finishing) represents the majority of home addition costs.
Finish Level Breakdown
Basic includes builder-grade materials: vinyl flooring, basic drywall, standard windows, minimal trim, and basic electrical. Suitable for utility rooms, garages, and budget-conscious projects.
Mid-Range includes mid-grade materials: hardwood or engineered flooring, upgraded windows, crown molding, recessed lighting, and standard HVAC extension. This is the most common choice for bedrooms and living spaces.
High-End includes premium materials: custom cabinetry, high-end flooring, designer fixtures, premium windows, custom millwork, and high-efficiency HVAC. Typical for master suites and luxury additions.
Addition Type Differences
Room additions ($80–$250/sq ft) are the most straightforward, involving foundation, framing, roofing, and basic systems. Bathroom additions ($150–$450/sq ft) cost significantly more due to plumbing rough-in, waterproofing, tile, and fixtures. Sunrooms ($100–$350/sq ft) feature extensive glazing and may require less HVAC. Second-story additions ($150–$450/sq ft) require structural engineering and temporary support but avoid foundation costs. Garages ($50–$200/sq ft) are the most economical since they need minimal finishes.
Additional Cost Factors
Our estimates cover construction costs but do not include architectural/design fees ($2,000–$8,000), structural engineering ($1,500–$5,000), building permits ($500–$2,000+), site preparation and grading, landscaping restoration, or furniture and appliances. Homes with complex rooflines, limited access, or outdated systems may incur additional costs.
Data Sources
Pricing data is compiled from HomeAdvisor, Angi, RSMeans, National Association of Home Builders (NAHB), and verified contractor estimates across multiple US regions. We review and update this data regularly to reflect current material and labor rates.
Last updated: 2026-02-08
Frequently Asked Questions
How much does a home addition cost? +
A home addition costs $80–$250 per square foot for a standard room, $150–$450/sq ft for a bathroom, $100–$350/sq ft for a sunroom, and $150–$450/sq ft for a second story. The total depends on size, type, finish level, and your local labor market. A typical 200 sq ft room addition costs $24,000–$50,000 at mid-range finishes.
Do I need a permit for a home addition? +
Yes, almost all home additions require building permits. You’ll typically need permits for structural work, electrical, plumbing, and HVAC. Permit costs range from $500 to $2,000+ depending on project size and your municipality. Building without permits can result in fines, forced removal, and problems when selling your home.
What is the ROI of a home addition? +
Home additions typically recoup 50–70% of their cost at resale. Bathroom additions offer the best ROI at 55–65%, followed by bedroom additions at 50–60%. Sunrooms return about 45–55%. Two-story additions can recoup 60–70% due to the efficient cost per square foot. The ROI varies significantly by market and quality of work.
How long does a home addition take to build? +
A small room addition (100–200 sq ft) takes 2–4 months. A bathroom addition takes 3–5 months due to plumbing complexity. A sunroom takes 1–3 months. A second-story addition takes 4–8 months. These timelines include permitting (2–6 weeks), but delays from weather, inspections, and material supply are common. Plan for 20–30% longer than quoted.
Is it cheaper to build up or build out? +
Building up (second story) costs $150–$450/sq ft, while building out (ground-floor addition) costs $80–$250/sq ft for a room. However, building up avoids the cost of a new foundation and doesn’t reduce yard space. If you need significant square footage and your foundation can support it, building up can be more cost-effective per square foot overall.
What is the cheapest type of home addition? +
Garage additions are the most affordable at $50–$200/sq ft because they don’t require plumbing, HVAC, or high-end finishes. Sunrooms are next at $100–$350/sq ft, especially prefabricated kits. Basic room additions cost $80–$120/sq ft with builder-grade materials. Converting existing space (attic, garage, basement) is typically cheaper than building new.
What adds the most value to a home? +
An extra bathroom consistently adds the most value, especially in homes with only one bathroom. A bedroom addition that brings the home from 2 to 3 bedrooms also adds significant value. Master suite additions with an en-suite bathroom are highly desirable. Quality of construction and consistency with the existing home style matter more than raw square footage.
What is included in home addition costs? +
Home addition costs typically include foundation/slab work, framing, roofing tie-in, exterior siding, windows, insulation, drywall, interior finishes, electrical wiring, and HVAC extension. Costs that may be extra include architectural plans ($2,000–$8,000), engineering ($1,500–$5,000), permits ($500–$2,000), landscaping repair, and furniture/fixtures.
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