Photo by Doug Koontz Architect Gary Baker looks over the Cannon Hill office building he designed to be green, reusing items like stone found on the lot.

The original builders of Frederick 's historic district buildings never knew the features of their houses would become part of a new design trend.

However, enhancing a home in the historic district with modern "green" or environmental features takes some innovation when facing approval from the city's Historic Preservation Commission.

Despite Frederick 's historic buildings never being intended as green structures, many of their most common features already increase efficiency, city historic planner Emily Paulus said.

Adding green features to the exterior of a historic house is subject to approval by the preservation commission, but is encouraged so long as the features don't detract from the historical character of the building, Paulus said.

"I don't know (if) it can be argued that a modern building is going to be more energy efficient than a historic building," she said.

With most structures in the historic district built before air conditioning and heating, they were made to maximize heat and light, Paulus said.

Thick masonry walls and natural building materials retain heat and cold more efficiently, she said.

The city must approve any major changes on the exterior of a building in the designated historic district. That includes the type of materials used.

Many property owners look at vinyl-framed windows as an efficient alternative to wood-framed windows. Paulus said those newer windows are discouraged since original windows are an important part of a building's historic character and usually are not the biggest culprit in heat loss.

"Most heat loss occurs through the attic," Paulus said. That can be fixed with insulation.

Solar panels, what many think of first when envisioning environmental technologies, are allowed on historic buildings.

Paulus said the installation of solar panels likely would be approved by the commission if the panels are proposed for a section of roof not visible from a street.

She said she did not know of any historic district property owners who have installed solar panels.

"The commission is very accommodating in retrofitting or adding those technologies to the buildings as long as they don't cause any damage or remove any original features," she said.

Some state lawmakers are working to guarantee the rights of homeowners to install such panels in historic districts and other neighborhoods.

Delegate Karen Montgomery introduced a bill that would prohibit policies banning them from historic buildings and condominiums.

"It is my firm belief that with sensitivity and good placement, almost every property can accommodate solar panels," said the Montgomery County Democrat who lives in a historic home in Brookeville.

Montgomery's house Bill 71 would allow a local preservation board to regulate size, color and location of a solar panel but not prohibit its installation.

Frederick Delegate Sue Hecht has introduced a energy bill prohibiting homeowners associations from restricting solar panel installation.

Her bill did not apply to historic properties, but Hecht, a Democrat, said she wasn't "for or against" addressing the installation of solar panels on historic buildings.

"We want to encourage renewable energy," she said. "These systems are not ugly."

Creative reuse

Ken Anderer, a member of the historic preservation commission, said most "green" practices can be applied to a historic property.

"Sometimes it takes some innovation to incorporate those factors," said Anderer, an engineer accredited under the Leadership in Energy and Environmental Design Green Building Rating System.

The LEED certification system rates buildings on their energy and environmental efficiency and impact.

Anderer said he doesn't know of a LEED certified building in Frederick 's historic district, but didn't say it could not be done.

"It would take a good bit of imagination and effort to fulfill enough of the criteria," he said.

The interior of any house in the historic district does not fall under the scrutiny of the preservation commission. Owners would be allowed to install water-saving fixtures, highly efficient heating and cooling systems or sustainable flooring.

Reuse and restoration of a building, if done right, is an inherent green practice, he said.

"One of the criteria in the LEED certification is the reuse of buildings," Anderer said. "That certainly is a basic tenet off the LEED program."

Green equals good design

When designing the Cannon Hill Office Building on East South Street, architect Gary D. Baker used recycled materials and built-in features that would add efficiency.

The building is new but could easily be passed over as an existing structure that had been renovated.

Stones from the site and a local abandoned house were used to build a base wall. Brick was brought in from Hagerstown.

Inside, floors and support beams were crafted from lumber taken from an old warehouse in Woodsboro , Pa.

Using local and recycled material, Baker said, was cheaper and more efficient.

The building and its features were welcomed by the city's preservation commission, he said.

"The good thing about the historic district is they like you to use as much real material as possible," Baker said.

A clear story or portion of the roof that juts up from the rest of the building draws hot air upward and naturally vents the structure. Large windows on the east and west side allow the sun to naturally warm the inside throughout the day.

"That is part of sustainable architecture, using less energy to maintain a building," Baker said.

Green architecture in a historic district for Baker is synonymous with good practical design.

"In today's design market it's a new buzzword," he said. "For us who have been around, it's old news."