Exploring Modular Additions

We were recently approached by an architect and a general contractor to explore whether a modular unit could be integrated into an existing site-built home to create additional living space. The idea raised thoughtful questions around design coordination, structural integration, zoning considerations, and how factory-built construction can complement traditional building methods without disrupting them.

This post marks the beginning of that exploration. Rather than presenting a finished project, we’re sharing the process — the questions, constraints, and opportunities that come up when modular construction is considered as an addition rather than a standalone home. As with many projects, feasibility depends on site conditions, design requirements, and regulatory factors, and not every concept moves forward.

Our goal is to document what we learn along the way and provide insight for architects, builders, and homeowners who may be evaluating similar possibilities. Whether this concept advances or simply informs future projects, the process itself offers valuable perspective on when modular additions make sense — and when they don’t.

This exploration began when an architect reached out after being referred by a local general contractor. The client was interested in adding a mother-in-law suite to an existing site-built home in Ormond Beach, and the team wanted to explore whether a modular unit could serve as the primary structure for the addition.

Rather than replacing the architect’s design intent or the contractor’s scope, the goal was to evaluate whether a factory-built unit could integrate cleanly into the overall plan — structurally, visually, and logistically — while keeping the builder in control of site work, foundations, utilities, and finishes.

Early conversations focused on feasibility, not commitment. The architect and contractor were clear that this was a conceptual exercise before significant design time or site costs were incurred.

Key questions included:

• Can a modular unit function as an addition rather than a standalone home?
   
• Can certain components — like cabinetry and finishes — be completed on site by others?
   
• How much flexibility exists for minor wall layout adjustments?
   

These are exactly the kinds of questions that determine whether modular construction is a fit — not just whether it’s possible.

One of the most important takeaways from this stage was that modular doesn’t require starting from scratch. The architect expressed interest in staying close to the manufacturer’s standard floor plan, with the understanding that:

• Minor wall layout changes could be reviewed and evaluated
   
• Kitchens could be delivered with rough-ins only, allowing cabinetry and finishes to be completed on site
   
• Exterior elements — such as tying a front porch into the existing home — could be handled by the contractor after set
   

This approach preserves predictability while still allowing customization where it matters most.

A major driver of this discussion was efficiency. By exploring a factory-built structure, the team could evaluate whether:

• The unit could be manufactured while the contractor priced foundation and site work
   
• Design decisions could be finalized earlier in the process
   
• On-site disruption to the existing home could be minimized
   

This parallel workflow is often where modular construction delivers its biggest value — especially for additions and infill projects.

 At this stage, the team is reviewing floor plan options, rough pricing, and site constraints before deciding whether the concept moves forward.

Whether this project advances or not, the process highlights something important:

Modular construction works best when it is treated as a collaborative tool, not a replacement for architects or builders.
 

These early feasibility conversations help everyone involved make informed decisions — before drawings are finalized, budgets are locked, or expectations are set too high.