Thinking outside of the box
By: CARRIE WATSON
For most people looking to build their own home, a 17-foot by 18-foot concrete block sitting smack-dab in the center of an otherwise attractive lot may be a deterrent, but not for Randy Fromberg. An architect with Fromberg Associates Inc. in Austin, Texas, Fromberg first found the available lot when his son Chase, now 17, was in elementary school. "I happened to drive past this lot, which is on top of a hill, and the first thing that caught my eye was the view," Fromberg says.
Indeed, the panorama from the hilltop, one of the highest elevations in the area, is unmatched: to the west the Texas hill country rises and falls infinitely before you, while, to the south, Austin's distinctive skyline shimmers in the sun. "I just loved the neighborhood, which is old and eclectic, and I loved the view," Fromberg adds. "It just seemed right. The lot had been on the market for a while when we bought it. I think the concrete box was a drawback in selling the lot, but I saw it as a real asset."
At one time, the entire site served as the area's utility plant, holding, among other things, a water well and a fire tower. When Fromberg discovered the site, the concrete box was useless. However, it once served as the neighborhood water tank and, in later years, as an observation tower. The half-acre lot around the tank had become a makeshift dumping ground for area developers, who would discard boulders and rubbish on the lot — another deterrent for would-be buyers.
But the concrete tank served as inspiration for Fromberg, who ingeniously realized the tank was the perfect size for a room. "We bought the lot and spent about a year designing the house around the concrete tank," he says. "There were a lot of people involved in the design effort, and we finally got it worked out, though we were a year behind schedule."
Fromberg became the architect, contractor and client, and the project became a full-time job. As for the home's construction, Fromberg decided to build an exposed concrete masonry home using split-face blocks. He designed a 16-foot by 16-foot by 32-foot split-face concrete block, adjacent to the old concrete tank and comprising the home's central living areas. Adjoining one end of the split-face block and the concrete tank, Fromberg added a two-story bedroom wing, which holds the master suite, including an office and a study. The children's rooms are located beneath the master suite, and one of the tank's concrete walls even forms part of a wall in Fromberg's daughter's bedroom.
"I wanted to use some of the concrete construction systems that we use in commercial construction, but not have the home look like commercial construction," Fromberg says. "I have always toyed with the idea of blending split-face concrete masonry units (CMUs) that are limestone colored with real limestone, and that is what we did. The block and the limestone went together really well — it is kind of hard to tell them apart."
Since limestone is a primary geological material in Austin, visible in ridges and exposed bedrock throughout the city, the house achieves a unity with the site that could never have been attained using other, more traditional building materials. The structure seems to blend with its surroundings, never disturbing but belonging to the land and to the terrain.
"I think people are used to seeing gray cinder blocks and cast concrete that looks very sterile and institutional, and almost unnatural," Fromberg says. "But I think the way we used, treated and combined the concrete with natural materials, it blends great and looks very natural. Split-face block can be a very warm material."
Inside the home, various stone and concrete elements, as well as the expansive views, connect the home to the exterior environment. Glass block units, inserted high in the structural walls, allow natural light to flow into the house. Interior stained concrete floors and stone countertops in the kitchen allow for minimal maintenance and a natural appearance. A massive free-standing stone fireplace, capped with a one-of-a-kind steel flue pipe, separates the dining and the living rooms. The flue is an industrial piece that exudes beauty in the double-height room.
The split-face blocks also provided some architectural freedom for Fromberg, who maneuvered them to add decorative detail to the home. "On the outside, the headers over the doors and openings are smooth, and the wall is rough, while on the inside, the wall is smooth and the headers are rough," he says. "It gives the wall contrast."
As for the concrete tank, Fromberg decided to cut two chunks out of the tank to make a window and a door in order to turn the space into a playroom for Chase and his daughter, Allix, 14. "At first the only way into the old tank was through a cut-out concrete hatch that you could lift and look in," Fromberg says. "You can imagine, after years of holding water, there were animal skeletons and all kinds of things. But the sandblaster got all of that out — we cleaned it really well.
"You wouldn't believe how it complicates things to have a piece, right in the middle of the site, that you have to build around and that is not easy to manipulate. But we wanted a house that did not look brand new when it was finished. The concrete block we built around, after we cleaned it up and sandblasted it, looked just like an ancient piece of a building."
In order to ensure the concrete room's structural integrity, Fromberg removed a center column and ran wood beams across the ceiling. After consulting a structural engineer, however, Fromberg also placed steel beams for added support. The result is a room that resembles a safe room in its construction and structural capabilities. "If there were a tornado or anything similar, this is definitely where I would be," he says of the concrete water tank turned playroom. Fromberg also studded up and insulated two walls and furred out two opposite sides in order to run electricity into the room.
In addition, the sheer mass of the concrete walls offers enhanced resistance to sound transmission. "The biggest problem I had with the house is that it is so open that you can hear everything, everywhere," Fromberg says. "But the playroom is really soundproof. When the kids have friends over, there will sometimes be half a dozen kids piled in there, but you can't hear anything from the rest of the house."
Since Fromberg's home sits exposed on a hilltop, in full view of the often-intense Texas sunshine, concrete was really the material of choice for the home's construction due to its ability to impede the passage of heat through walls. The 8-inch thick CMUs were interior insulated with vermiculite, and according to Fromberg, the home stays cool in the summer and warm in the winter, cutting energy costs in the process. "The wall facing the setting sun will be really warm on the exterior, but on the inside, you do not feel any heat at all — there is really a thermal lag of heat going through the wall."
With the help of his entire family, including his wife, Karen, Fromberg had his home functional and presentable just in time to be featured in the American Institute of Architects (AIA) Austin Homes Tour. If given the opportunity, Fromberg says he would use concrete blocks again in residential construction. "I think concrete is a great material," he says. "It is so durable, and you can use it in so many ways, such as modular construction like concrete blocks, to the other extreme, pre-form concrete. After being on the design side, being on the construction side really makes you appreciate the decisions you make."
Faced with the challenge of designing his home around an immobile and awkward concrete tank, Fromberg never hesitated to build on the lot, converting the old concrete water tank into one of the most comfortable and warm rooms in his home. And, considering the hilltop's incomparable view, how could Fromberg have ever passed up the challenge?