Expand your home and enhance your lifestyle with our Home Additions Cost Calculator. Whether you’re planning a larger kitchen, a new primary suite, or additional living space, this tool helps you estimate what it takes to bring your vision to life, with a general cost range based on typical design-build additions in the Seacoast New Hampshire region and insight into how size, materials, and overall scope can influence your total investment.
Welcome to Our Home Additions Cost Calculator
Estimate My Home Addition Cost:
1. Enter Your Project Details
Add your project size, design features, and upgrades. Costs depend on square footage, material selections, and any plumbing, electrical, or structural changes. See the specifications section below the calculator for details.
2. Review Your Estimated Range
Get a general estimate to support early planning. For a precise quote, we’ll meet with you to review your home, design preferences, and construction needs.
Additions
Estimated Cost
Scope of work (base)
No. of hours consultancy (per hr/$10)
Scope of Work (base)
Finish Spaces with-in Addition
Specifications:
Home Addition Project Types
Our calculator provides cost ranges based on the type and scope of addition you’re considering. Here’s what to expect from each level:
- 16x18 Addition - (280 sf)
Ideal for expanding your living space without major structural changes. This option typically includes a single-room addition such as a sunroom, home office, or small bedroom. It maintains existing utility connections and focuses on adding functional square footage with quality finishes.
- 20x24 Addition (480 sf)
A balanced approach that includes moderate structural work, upgraded finishes, and new mechanical systems as needed. Examples include kitchen or family room expansions, attached garages, or new primary suites with standard en-suite bathrooms. This level may involve integrating new roofing and siding to match your existing home.
- 20x24 Two Story Addition (960 sf)
A full-scale expansion that transforms the layout and functionality of your home. This may include multi-story additions, major kitchen or primary suite expansions, or additions that redefine the home’s flow. These projects often involve custom architecture, significant structural work, and high-end materials for a seamless and elevated result.
Factors That Influence the Cost of a Home Addition
- Foundation and Structural Work
The complexity of your addition’s foundation and framing can significantly impact cost. Adding a second story or expanding into uneven terrain requires more engineering and materials than building on a simple slab or crawlspace.
- Exterior Integration
Matching roofing, siding, and trim to your existing home ensures a cohesive appearance. Custom details or specialty materials can increase cost but provide lasting visual appeal and value.
- Windows and Doors
Adding or enlarging windows and exterior doors improves natural light and access but involves additional framing and finishing work. Higher-end window packages or custom patio doors can elevate both style and comfort.
- Plumbing and Electrical Systems
Additions that include kitchens, bathrooms, or laundry areas require plumbing and electrical extensions. The complexity of this work depends on proximity to existing systems and the level of new fixtures or lighting being added.
- Interior Finishes and Features
Flooring, trim, built-ins, and fixtures define your addition’s look and feel. Selecting hardwoods, custom cabinetry, or designer lighting enhances quality but will also affect cost.
- HVAC Integration
Depending on the size and purpose of your addition, your existing HVAC system may need to be upgraded or extended. This ensures even comfort throughout your home and efficient energy use.