Accessory Dwelling Units, Part V: The Modular (Built Off-Site)

ADUs – detached accessory or additional dwelling units, also called mini homes — are a growing trend. They use an existing parcel of residential real estate to create an additional residential unit. They are often used for intergenerational housing (aging parents, 20-somethings just starting out, etc.) and have long-term value as rental property while adding to the value of the real estate.

This installment is about modular construction, which is how the construction industry refers to buildings assembled in a manufacturing plant (off site). They are assembled (conforming to building codes) into modules that are delivered to the site on trucks and installed with a crane. ADUs are an ideal application for modular construction because they typically require only one or two modules. John Phillips’ company, Verdant Living, handles only modular ADUs, assembled by Champion Homes in a York, Nebraska, factory.

Modular construction has many advantages over on-site construction:

Cost – can be 20% less than traditional building techniques

Speed – up to 40% faster, the site can be prepared simultaneously with the unit being assembled.

Quality – unit is assembled in a factory-controlled environment.

Less disruption – far less construction in your backyard

Weather independence – unit construction is done indoors

Less hassle – far less construction in the backyard, fewer contractors on site (4 as opposed to 19)

Environmentally friendly – less waste, smaller carbon footprint

And much more.

Gary Fleisher, a leading observer of and consultant to the modular construction sector, lists 25 reasons modular is a great choice (and 25 hurdles it needs to overcome) which you can read at https://modularhomesourcepro.com/solving-the-affordable-housing-crisis-the-promise-and-pitfalls-of-modular-and-prefabricated-housing/

There are so many advantages, one might ask why someone would not use modular construction. A couple of reasons:

One big practical reason is site access. There needs to be a way for delivery using a crane, although other delivery methods are possible, crane delivery is typical.

Another reason is personal/emotional. If the buyer has specific design preferences or needs, they may wish to hire an architect, work through the design process, review and meet local requirements (maybe requiring special approval), hire a contractor, help organize the construction project including coordinating subcontractors, and take the additional time necessary for the project (estimates are often as long as two years), all of which, of course, would incur significant extra expense. The result can be very good, but requires money, time, and patience.

The purchasing experience for a modular unit is different (at least when buying from Champion Homes through Verdant Living). It is more like buying a car. Choose a model. Choose the finishes. Choose accessories (units are delivered with appliances already installed). It is delivered and installed on a foundation, thus much simpler than “stick built” on site. However, there is still a lot to get done — Local government approvals, permits, inspections; site work, including water and sewer connection; and any on-site work needed to complete the project.

A note of caution: as with any significant purchase (and buying a mini home is a major one), the purchaser should choose the modular manufacturer carefully, and make sure the site work and installation is handled by a reputable general contractor (often supplied by the manufacturer’s local representative).

To help those interested in ADUs, Verdant Living has published a buyer’s guide, BuyersGuideColoradoADUs.com. A good place to begin is the Verdant Living website, VerdantLiving.us, or contactJohn Phillips at 303-717-1962.

I want to thank the following additional people for their input: Gary Fleisher, Modular Home Source Pro, Aaron Trometter and Doug Tollin, Champion Homes, and Steve Payne, Vantem.

Next month: A recap of this 6-part series and some key takeaways.