Turn Unused Space Into a Private Apartment, Rental Income, or Family Suite

For 40 years, Next Level Builders has been building the additions, in-law suites, and expanded living spaces New Hampshire homeowners now call ADUs. Whether you want to bring family closer, create rental income, or make your property more flexible, we can help you understand what your home can support.

  • Specialized ADU builder in New Hampshire
  • 40 years building additions and expanded living spaces
  • ADUs for parents, adult kids, renters, guests, and future downsizing
  • Start with a property review, not a sales pitch

No pressure. No obligation. Get a practical next step from an experienced NH builder.

Why NH Homeowners Are Looking at ADUs Now

Some ADUs are family-first. Some are income-first. Many become both over time.

Bring Adult Kids Home

A real place to live with independence and privacy, without leaving the area.

Plan an Adult Child ADU

Bring Parents Closer

A private, manageable space for parents downsizing near children and grandchildren.

Plan a Parent ADU

Create Rental Income

A legal apartment can offset property taxes, insurance, and monthly housing costs.

Explore Rental Potential

Create Long-Term Flexibility

Family space now. Rental, caregiver, guest, or downsizing option later.

Explore My Options

Which ADU Path Sounds More Like You?

I am building for family

You may be thinking about a parent, adult child, guest, caregiver, or future downsizing plan. We can help you think through privacy, safety, access, layout, and comfort.

Plan a Family ADU

I am building for income

You may be looking for rental income, property tax offset, mortgage relief, or long-term property value. We can help you think through the space, cost drivers, rental use, and next steps.

Explore Rental ADU Potential
Your Options

What Kind of ADU Could You Build?

Every property is different. Next Level Builders can help you evaluate the best option based on your goal, budget, space, utilities, and local rules.

Illustrative rendering of a detached backyard ADU
Maximum Privacy

Detached Backyard ADU

Best for:Rental income, adult children, parents, or private guest space
Pros:Most privacy. Strong standalone feel. High appeal for renters and family
Detached
Illustrative rendering of an attached ADU addition
Connected To Home

Attached ADU Addition

Best for:Homeowners who want a new apartment connected to the existing home
Pros:Can blend with the main home. Good for parent or family use. Flexible layout
Attached
Illustrative rendering of a garage conversion ADU
Existing Footprint

Garage Conversion

Best for:Properties with an existing garage or carriage-style structure
Pros:Uses an existing footprint. May reduce exterior disruption
Conversion
Illustrative rendering of a basement or interior ADU
Lower-Level Space

Basement or Interior ADU

Best for:Homes with underused lower-level or bonus space
Pros:Lower exterior impact. Can be practical where yard space is limited
Interior
Illustrative rendering of an in-law suite or apartment addition
Family-First

In-Law Suite or Apartment Addition

Best for:Family-first ADUs and multi-generational living
Pros:Designed around privacy, safety, comfort, and long-term family use
Addition

Images in this section are illustrative representations of possible future builds by type. They are not photographs of completed Next Level Builders projects. See the photo gallery for our real work.

Why Homeowners Choose Next Level Builders for ADUs

40 Years of Relevant Experience

Next Level Builders has spent decades building additions, in-law spaces, renovations, and expanded living areas. ADUs may be newly unlocked for more homeowners, but the construction work is familiar.

Specialized in ADUs

An ADU is not just a small renovation. It requires smart thinking around privacy, entry, kitchen and bath planning, utilities, parking, town requirements, family use, and rental use.

Renovation and Custom Build Capability

Some ADUs are straightforward. Others touch the existing home, basement, garage, utilities, rooflines, or foundations. Next Level Builders can handle more than a simple backyard structure.

Real Photos, Real Work

The company has a deep photo library of real completed projects. Real work is a better proof point than any description of craftsmanship.

Feasibility Before Pressure

The first step is not a hard sell. It is understanding what your property, goals, budget, and timeline may support. No pressure to commit until you know the possibilities.

Family and Income Lens

Some homeowners are helping kids. Some are helping parents. Some need rental income. Some want future flexibility. The right ADU starts with the right goal, not a generic floor plan.

The Process

A Clear ADU Process From First Question to Finished Space

Property Review

Tell us where the property is, what space you have in mind, and what you want the ADU to accomplish.

Feasibility Conversation

We discuss likely ADU types, property constraints, rough project considerations, and the questions that need to be answered.

Concept and Scope

We help define the right direction: detached ADU, attached addition, garage conversion, basement apartment, or in-law suite.

Planning and Permitting Path

We help identify the local requirements and construction path so the project can move from idea to buildable plan.

Construction

Next Level Builders manages the build with the experience of a company that has completed additions and renovations for decades.

Final Walkthrough

The finished space should feel complete, useful, and appropriate for your property, whether it is used for family, rental income, guests, or future flexibility.

Free Property Review

Start My Property Review

You do not need to know the rules, the layout, or the budget before you reach out. Tell us what you are trying to accomplish, and Next Level Builders will help you understand the next practical step.

Not sure what type of ADU you need? That is what the property review is for. No plans needed. No pressure to build. Bring the goal. We will help think through the space.

No pressure. No obligation. Form or phone, whichever is easier.

Homeowners Want a Builder They Can Trust

On time, every time. Questions needing answers were only a phone call away.
William & Nancy Homeowners, Saugus, MA
The addition is even better than I expected. I made a lot of changes along the way and it was done with no trouble at all.
Corine & Bill Homeowners, Littleton, MA
Tom & associates have always been friendly, consistent, extremely knowledgeable, and professional.
Les & Heidi Homeowners, Wolfeboro, NH

Questions Homeowners Ask Before They Call

An ADU, or accessory dwelling unit, is a second living space on the same property as a primary home. It may be detached, attached, converted from existing space, or built as an apartment-style addition, depending on the property and local requirements.
Next Level Builders specializes in ADUs, but also completes renovations, additions, and custom project builds. That broader construction experience matters because many ADUs require tying new living space into an existing home, garage, basement, utility system, or exterior structure.
Next Level Builders has 40 years of experience building additions, in-law suites, expanded living spaces, renovations, and related projects. The ADU opportunity has grown because laws have changed, but the construction experience is not new.
Because you are not buying another parcel or competing for another property. You are improving land you already own. For the right property, that can make the economics more attractive than buying a separate rental property.
In some cases, it may. For example, in Portsmouth, a one-bedroom ADU may rent for around $2,500 per month while an illustrative fully financed construction payment may be around $1,300 per month. Every project is different. Homeowners should account for taxes, insurance, utilities, maintenance, vacancy, financing terms, construction cost, and local rules.
No. Many homeowners build ADUs for family first. Common uses include adult children, aging parents, caregivers, guests, future downsizing, and long-term family flexibility.
Often, that is one of the strongest reasons to build. An ADU can give a parent a private, manageable living space close to family while helping preserve independence and privacy.
Many homeowners consider ADUs because local housing is expensive and hard for adult children to access. A well-planned ADU can give an adult child independence while keeping family nearby.
That depends on your town, property type, lot, utilities, setbacks, septic or sewer, parking, design, and other requirements. That is why the first step is a property review.
New Hampshire ADU rules have expanded the opportunity for homeowners, but local requirements still matter. The exact path depends on the municipality and project. Next Level Builders can help you understand the questions to ask and the likely path.
Cost depends on the type of ADU, size, utilities, site work, finishes, existing structure, and local requirements. A detached ADU will usually have a different cost profile than a garage conversion, basement apartment, or attached addition.
Timeline depends on design, permitting, scope, site conditions, and construction complexity. Every project is different. The best first step is a property-specific conversation.
Adding a legal living unit may affect assessed value, taxes, and insurance. Homeowners should consult local and professional advisors. Next Level Builders can help identify the practical project questions to ask.
Yes. Calling is just as valid as filling out the form. Call (603) 531-7300 to speak directly with Next Level Builders about what your property may support.

Find Out What Your Property Could Become

Whether you are thinking about an adult child, an aging parent, rental income, rising property taxes, or future flexibility, the first step is the same: find out what your property can support.

A short conversation can save weeks of guessing.