Free Home Addition Cost Estimator (2026) | Room Addition Calculator
How much does a home addition cost in 2026? Get a free estimate by ZIP code — adjust size, layout, and finishes. Use Remodelum to build your budget, iterate your costs, compare quotes and track your expenses.
Get started
Get your home addition renovation estimate
Tell us about your project and we'll build a ZIP-code accurate, category-by-category cost estimate. Takes under a minute.
Estimate No. RA-20260823-11213
Home addition estimate
A complete budget for a 200 sq ft home addition in ZIP code 11213, with mid-range finishes. The categories and amounts below come from the provided project data.
A detailed planning budget organized by professional services and project purchases.
- ZIP code
- 11213
- Country
- USA
- Renovation
- Home addition
- Finish quality
- Mid-range
- Area
- 200 sq ft
Detailed cost breakdown
The full budget is organized into professional services and purchases. Expand or collapse either section to review every category and its scope.
Professionals · 18 categories$63,630
Labor, design, construction, installation, and project-management services.
| Category | Scope | Cost |
|---|---|---|
| Fees, profit and overhead | Cover contractor fees, project management, and overhead costs associated with managing the home addition project. | $8,820 |
| Carpentry and framing | Perform structural framing for the new addition, including walls, roof, and any necessary custom carpentry for built-ins or unique architectural features. | $7,560 |
| Siding and exterior | Install new siding on the exterior of the addition to match the existing home, ensuring weatherproofing and aesthetic consistency. | $5,040 |
| Electrical | Install new electrical wiring, outlets, and lighting fixtures in the addition to ensure functionality and compliance with electrical codes. | $5,040 |
| Roofing | Install new roofing materials to cover the addition, ensuring it matches the existing roof in style and material. | $5,040 |
| Architect | Engage an architect to design the addition, ensuring it integrates seamlessly with the existing structure and meets local building codes. | $3,780 |
| Drywall and insulation | Install and finish drywall in the addition, along with necessary insulation to ensure energy efficiency. | $3,780 |
| Plumbing | Install new plumbing lines to service the kitchenette in the addition, ensuring proper water supply and drainage. | $3,150 |
| Designer | Engage a designer to assist with interior layout and finish selections for the addition, ensuring aesthetic coherence with the existing home. | $2,520 |
| Painting | Paint the interior walls, ceilings, and trim of the addition, using mid-range paint for durability and aesthetic appeal. | $2,520 |
| Mechanical | Service existing mechanical systems to integrate with the new addition, including HVAC and plumbing adjustments. | $2,520 |
| Countertop | Install a countertop in the kitchenette area of the addition, using mid-range materials for durability and style. | $2,520 |
| Window and door installation | Install new windows and doors in the addition, ensuring proper fit and insulation. | $2,520 |
| Flooring | Install new mid-range flooring in the addition, suitable for a residential space. | $2,520 |
| Thermal, moisture and air sealing | Ensure the addition is properly sealed against thermal, moisture, and air infiltration, using appropriate sealing materials and techniques. | $1,890 |
| Finish and trim | Install finish and trim work in the addition, including baseboards, crown molding, and other decorative elements. | $1,890 |
| Tile installation | Install tiles in the kitchenette area of the addition, ensuring proper setting and alignment. | $1,260 |
| Demolition | Perform necessary demolition to prepare the site for the new addition, including removal of any existing structures or landscaping. | $1,260 |
Purchases · 11 categories$29,500
Materials, fixtures, equipment, furnishings, permits, and other project purchases.
| Category | Scope | Cost |
|---|---|---|
| Building materials | Purchase materials for constructing the addition, including lumber for framing, drywall, insulation, and mid-range flooring materials. Also includes paint for walls and ceilings. | $8,000 |
| Cabinetry and built-ins | Install new cabinetry in the additional space, including a small kitchenette with mid-range cabinets and a built-in closet for storage, sized for a 200 sqft area. | $5,000 |
| HVAC equipment | Install a new HVAC system or extend the existing system to accommodate the additional space, including ductwork and a thermostat. | $3,500 |
| Furnishing | Purchase furnishings for the addition, including basic furniture and decor to complement the new space. | $3,000 |
| Doors and windows | Purchase and install new windows and doors for the addition, ensuring they match the existing home's style and provide adequate insulation. | $3,000 |
| Plumbing fixtures | Install plumbing fixtures in the addition, including a sink and faucet for the kitchenette. | $1,500 |
| Tiles and stones | Install tile flooring or backsplash in the kitchenette area of the addition, using mid-range tiles. | $1,500 |
| Lighting | Install new lighting fixtures and switches in the addition, ensuring adequate illumination and style consistency with the existing home. | $1,500 |
| Miscellaneous | Cover any additional materials or unexpected costs that may arise during the construction of the addition. | $1,000 |
| Permits | Obtain necessary permits and inspections for the construction of the addition, ensuring compliance with local regulations. | $1,000 |
| Hardware and fasteners | Purchase and install necessary hardware and fasteners for the addition, including door handles, cabinet hardware, and construction fasteners. | $500 |
Analysis and assumptions
This provided budget includes professional services and purchases for the stated location, area, renovation type, and mid-range finish quality. Actual costs can vary with site conditions, selections, taxes, and changes to scope.
- Plan scope
- Compare proposals
- Track purchases
- Record payments
COST BY ADDITION TYPESTypical 2026 costs by addition type
Average structural investment ranges by project type and finish tier
| Addition Type | Low Tier | Mid Tier | High Tier |
|---|---|---|---|
| Bedroom Addition | $40,000 | $90,000 | $180,000 |
| Bathroom Addition | $25,000 | $60,000 | $130,000 |
| Sunroom / Enclosed Porch | $20,000 | $45,000 | $100,000 |
| Second Story Addition | $100,000 | $200,000 | $400,000+ |
| Garage Conversion | $15,000 | $35,000 | $75,000 |
*Note: Cost models are subject to regional labor variations, zoning restrictions, and site conditions. Low tier assumes basic materials and standard layouts; mid tier reflects upgraded fixtures and semi-custom engineering; high tier features premium architectural details and complex structural integration.