Granite State ADU is a new design–build company founded by longtime collaborators and friends Brayden Tuscher and Erik Jones. While the company itself is new, Brayden and Erik have worked together on residential projects across New England for nearly two decades, combining more than 40 years of hands-on design and construction experience.

Brayden is the founder of Tuscher Design Group, known for thoughtful, high-quality residential architectural design. Erik is the founder of Econeered by Design, bringing decades of real-world construction experience to every project. Together, they created Granite State ADU to focus exclusively on well-designed, efficient, and buildable accessory dwelling units in response to New Hampshire’s new ADU law.

This long-standing collaboration allows Granite State ADU to offer homeowners a single, accountable team from zoning analysis through final construction.

An Accessory Dwelling Unit (ADU) is a secondary dwelling on the same property as a single-family home. Thanks to New Hampshire’s House Bill 577 (effective July 1, 2025), homeowners now have by right permission to build both attached and detached ADUs in any zone that allows single-family homes, subject to the same basic standards (setbacks, height, lot coverage, etc.). The law also raises the maximum ADU size to 950 sq ft in many communities. For more detailed guidance, see the state’s official Accessory Dwelling Unit Guide for Homeowners (RSA 674:71–73). We offer a free Zoning Analysis tool so you don’t have to try and figure it all out on your own!

Detached ADUs typically offer greater privacy, greater site-planning flexibility, and fewer constraints from the existing structure. Attached ADUs can suit specific properties but may require more structural coordination and, oftentimes, higher costs. We design and permit both and will recommend the best fit for your lot and budget.

“Tiny homes” are treated as manufactured or mobile housing and often are not permitted by local zoning. Granite State ADUs are permanent, code-compliant homes built to the International Residential Code (IRC) and New Hampshire building standards with full utilities and foundations. We offer both traditional site-built methods and modular construction options, depending on your needs—both result in legal, mortgage-eligible ADUs.

A well-planned accessory dwelling unit can be a smart long-term investment. By creating a fully independent rental space, an ADU can generate steady monthly income—often enough to offset mortgage or property-tax costs. Because it adds a flexible, code-compliant living space, an ADU typically increases overall property value beyond the cost of construction.

An ADU also supports multi-generational living. For example, you can create a comfortable, private home for aging parents or in-laws on the same property. This arrangement can significantly reduce, or even eliminate, future expenses for assisted living or senior housing while keeping loved ones close. The ability to share care, meals, and household responsibilities can free up time and money and provide peace of mind for everyone involved. Grandparents on-site to help with child care costs? YES!

Every property and project is different. Site conditions, finish selections, and market factors all influence cost, which is why we price each ADU individually. Our 4 Easy Steps are designed to make that process clear from the start, beginning with a free zoning review and continuing through design development, where your plans and budget are refined together.

If you share your target budget early, we design intentionally around it so that quality, function, and cost stay in balance. In general, most projects fall between $325 and $375 per square foot, depending on the site's complexity, materials, and current labor and material costs.

To get started, complete our Free Zoning Analysis to learn what’s possible on your property and how your budget aligns with a realistic build path.

Yes. Granite State ADU partners with Merrimack Savings Bank, which offers construction loans specifically for accessory dwelling units. We coordinate plans and budgets with their team to streamline approvals.

A typical build usually takes 4-7 months from start to finish. We keep it simple with 4 easy steps:

1. Property Review — a free review to confirm what your lot allows and flag any issues.

2. Site Visit & Feasibility — align goals and evaluate existing structures and site conditions.

3. Design Development — a custom plan tailored to your needs, site, and budget (we can also help coordinate financing).

4. Construction — we handle permitting and build your ADU with a clear schedule and regular updates through move-in.

This structured process keeps timelines clear and efficient while ensuring your ADU is designed and built right the first time.

Absolutely. The plans in our Design Section are meant to spark ideas. As a full-service design–build firm, we customize every ADU to fit your site, needs, and budget.

Yes. Most plans are single-level and ADA-friendly, with features such as wider doors, accessible bathrooms, low thresholds, and accessible kitchen layouts to support safe, comfortable long-term living.

In most cases, no. New Hampshire law (RSA 674:72 V) does not require a brand-new septic system when adding an ADU unless the existing system is failing or unapproved. Typically, the only requirement is to have an updated septic design prepared and filed with the New Hampshire Department of Environmental Services (DES). Granite State ADU works with licensed septic designers across the state and can coordinate everything for you—from design updates and state paperwork to local approvals—so the process is seamless and doesn’t delay construction.

Absolutely. We are a full-service, one stop shop. We offer a free Zoning Analysis tool to get you started, then we prepare applications, attend municipal meetings (usually not even required), and coordinate all approvals. Our goal is a clear, efficient path from first conversation to building permit.