Custom modular homes

Your home.
Built your way.

A home that fits your life, with hands-on guidance from planning through on-site completion. Serving Pennsylvania, Maryland, and Virginia.

Owner-led guidance from Jim Spontarelli.
Built with Signature Building Systems.
An open kitchen and living area with a large island, pendant lighting, and custom cabinetry
Thoughtful layouts. Finishes you choose.
Space to make your own.

Local knowledge. Personal attention.

PennsylvaniaMarylandVirginia
Find your starting point

Big ideas. Thoughtful plans.

Start with a home you love. We’ll help tailor the layout, finishes, and details to your property and priorities.

Browse home plans

Shown as manufacturer design examples. Features, options, and final specifications vary by project.

The Modbuildr process

A clearer path
from idea to home.

There’s more to building a home than ordering the modules. We help you see the whole project and understand what comes next.

Talk through your project
  1. Start with your goals

    Talk through your location, property, budget, and the way you want to live.

  2. Plan the whole build

    Choose a design and account for site work, foundation, delivery, installation, and finish work.

  3. Prepare and coordinate

    Move through design, financing, permits, factory production, and site preparation with a coordinated plan.

  4. Set, finish, and move forward

    Coordinate the home set and agreed on-site work, then complete the inspections needed for occupancy.

Jim Spontarelli, founder and owner of Modbuildr
Jim SpontarelliFounder & Owner, Modbuildr
A builder in your corner

You’ll work
directly with Jim.

Jim brings experience from the manufacturer’s side of modular construction and the practical work of getting homes built on site.

He helps connect the design, factory, lender, and local trades so you can make informed decisions throughout your build.

Meet Jim and Modbuildr

A home that fits you

Explore custom homes, accessory dwellings, and additions with layouts and finishes suited to your needs.

A complete project picture

Understand the home cost alongside the work needed to prepare your property and complete the build.

Guidance at every stage

Work through planning, manufacturing, delivery, and on-site coordination with a clear point of contact.

A few common questions

Before you start.

Can I customize a modular home?

Yes. A manufacturer plan is a starting point. Jim can help you explore layout changes, exterior details, finishes, and a custom design suited to your property.

What goes into the total project budget?

The modules are one part of the budget. Depending on your property and scope, the project may also include land, permits, excavation, foundation, utility connections, delivery, crane and set, and on-site completion. We work through these items before you commit to a build.

Do I need to own land before contacting you?

No. If you already have a property, share its location and any available survey. If you are still looking, Jim can help you think through access, utilities, site conditions, and the type of home you want before you purchase.

Can you help with an ADU or addition?

Yes. Modbuildr works on accessory dwelling units and modular additions as well as new homes. Feasibility depends on the property, local approvals, and how the new structure will connect to the site or existing home.

How long will my build take?

The schedule depends on design, financing, permitting, factory availability, site work, and on-site completion. We discuss a project-specific timeline once the property and scope are understood.

What warranty comes with my home?

We review the applicable manufacturer, builder, and any third-party warranty documents for your project. Coverage, exclusions, and service responsibilities should be confirmed in your agreement.

Your next step

Let’s talk about the home you have in mind.

Have a plan, a property, or just an idea? Start with a conversation with Jim.