Understanding What an ADU Really Involves
Guy Williams Architecture works with clients who are considering converting or building an accessory dwelling unit on their property. Whether the goal is to create a private workspace, house a college-age child, provide a guest space for visiting family, or offer a comfortable and independent residence for aging parents, the firm brings architectural expertise to the planning process.
One practical use case for an ADU in the Twin Cities area is as a seasonal base for traveling parents or snowbirds. A well-designed unit can provide just the right amount of living space for a few months of the year, while the primary homeowner maintains oversight of the property.
An ADU Is a Full Residence, Not Just Finished Space
A key point that Guy Williams Architecture emphasizes is that an ADU is a complete house — not simply a finished room or loft. It requires electricity, water, sewer connections, a proper foundation, insulation, and a heating system. In Minnesota, where temperatures can drop to 20 below zero, these are not optional considerations.
A functional accessory dwelling unit also needs a toilet, shower, kitchen, and laundry facilities. This means underground water, sewer, and gas lines must be installed. In most cases, the sewer and water lines will need to run from the street in front of the existing home, extending the full length of the property.
For these reasons, simply "finishing" the space above an existing garage, barn, or stable is rarely a viable option. Unless the existing structure was originally built as a full carriage house, it is typically necessary to demolish the existing building and construct the ADU from the ground up. This applies to most projects involving older garages, barns, or century-old stables.
Cost Expectations for ADU Projects in the Twin Cities
Prospective clients should be aware that most ADU builds in the Twin Cities area start at a minimum of $250,000. This reflects the full scope of work involved — from site preparation and utility connections to foundation work and complete interior finishing.
Guy Williams Architecture helps clients understand the full picture before committing to a project, ensuring that expectations around scope, complexity, and budget are grounded in reality from the outset.
