For nearly a century, family-owned Miller Brothers has served drivers in Ellicott City, Maryland. Its latest investment is an expanded Cadillac showroom designed to strengthen the customer experience and improve vehicle flow through the building. Arium AE provided architecture and MEP engineering services for the addition and renovation, working alongside Wilhelm Builders. The project encloses a covered exterior display area to create a larger interior showroom. It adds a new vehicle delivery entrance, giving customers a more spacious and polished setting for one of the most memorable moments of the buying experience: taking delivery of a new car.
When Howard County adopted the International Energy Conservation Code (IECC) 2024, it changed how additions must account for renewable energy. Under the Renewable Energy Systems code (Section C502.3.8), an addition must comply with the energy efficiency requirements (Section C405.15) for the addition alone. Where a project includes no on-site renewable energy systems, the owner must procure that renewable energy in another way. Just as important for the schedule: the county will not release the building permit until that renewable energy agreement is in hand.
The renewable energy requirements do not apply to the full 6,000-square-foot project, only to the 1,392-square-foot addition. Arium used COMcheck energy modeling to establish the project requirements. Because the addition is in climate zone 4A with an off-site renewable energy factor of 1.35, it established an annual renewable energy requirement of 21,141 kWh. This is a small amount of renewable energy, and buying it is relatively inexpensive. However, a purchase this small isn’t worth the administrative effort for most renewable energy certificate (REC) sellers, who would rather transact at volume. Arium reached out through its network and connected Miller Brothers with a seller willing to handle a purchase this small and turn the paperwork around quickly. With the agreement documented through a letter of intent to procure the off-site renewable energy, the permit condition was cleared, and the project kept moving.
Evolving electric vehicle requirements also shaped the design. Miller Brothers hoped to install a demonstration charger inside the showroom so customers could see how the technology works up close. To manage costs, the team chose to place an additional exterior charger elsewhere on the site instead. The exterior location remains fully accessible for customer demonstrations while avoiding the added construction and fire protection measures an interior charger would require, keeping the showroom simpler and more economical to build.
The existing roof created a second constraint. Adding another roofing layer to meet current energy performance would have interfered with drainage and added weight, potentially triggering costly structural reinforcement on a building that was never designed to carry the additional load. Rather than reroof, Arium specified a lighter closed-cell spray foam insulation system that brought the addition up to current energy requirements while limiting added construction and cost.
The showroom’s sculptural metal panel facade is a special Cadillac-branded system. Arium designed the waterproof building enclosure behind the finish panel system. The two function as a single assembly, requiring close coordination between Arium’s enclosure design and the special skin so the envelope stays continuous and weathertight, and the finished branded exterior installs cleanly over a substrate built to receive it.
Miller Brothers Cadillac
Ellicott City, MD
High-Tech Manufacturing Facility
Germantown, MD
Core Development
Lexington Park, MD
Core Development
Hyattstown, MD
Fireline Corporation
Baltimore, MD
Exclusive Motorcars
Randallstown, MD