When I was a kid, the attic of our house was a scary and exciting place. All sorts of adventures waited there for anyone who dared to part the cobwebs and crawl into the dusty darkness. It was a mysterious, secret realm, reached only through a tiny panel in the top of my parent’s closet. I wasn’t supposed to go into the attic, but what kid can resist exploring a hidden room in the house?
Here in the Midwest, lots of kids have similar memories. The pitched roofs that shed our summer downpours and winter snows creates that space under the rafters that we call the attic. It’s a storage space, or an extra bedroom, or it may not be used at all, but the space exists out of architectural necessity. The image of a roof, in fact, is synonymous with shelter; the pitched roof and the attic underneath it are a part of our culture.
The roof of a house is obviously a major component of the construction and a key element in the overall architectural composition. It shelters the interior of the building from the weather, protects the sidewalls and windows from sun and rain, but has an equally important role in determining the character of the design. Home styles, in fact, are usually strongly identified with a particular roof style.
The New England “salt box” is easily recognized by its asymmetrical gable; Prairie style is characterized by deep overhangs and very low sloped, often flat roof forms. Victorian homes are well known for steep pitches, complex massing, and elaborate detailing. And the roofs of many Southwestern Adobe-styled homes are completely hidden behind parapet walls.
How does an architect choose a roof style and construction for a home? The first consideration is always the climate of the site. In northern climates roofs must shed heavy snowfalls and insulate the interior during the winter months so they tend towards steeper, thicker construction. Several very innovative construction techniques have been developed to “superinsulate” residential roofs against long, cold northern winters and prevent the ice-damming problems that can occur in that climate.
In the arid Southwest, the relentless sun can quickly overheat the interior of a house if it’s allowed to shine directly in through the windows. Deep overhangs, like those popularized by many of Frank Lloyd Wright’s houses, allow the sun into these homes for only a few short hours of the day. The overhangs help keep the interior cool while allowing large expanses of glass to capture views of the surrounding desert. Lighter colored roofing materials also reduce the daytime heat build-up in hot climates.
Particularly vulnerable to the weather are the roofs of seaside homes. Salt spray and strong winds cause many roofing materials to degrade more quickly. In Florida, better homes sport metal or concrete-tile roofs, materials that can last 70 years or more. Again, lighter colors predominate, lowering the temperature of the roof surface and extending its lifespan. New England seaside homes may have traditional wood shingle or shake roofs that, when properly maintained and allowed to weather naturally can last the life of the house.
The architectural heritage of the region and the context of the immediate site may also influence roof choices. Many new homes have roofs designed to blend seamlessly with the styles already prevalent in the area. Historic neighborhoods often establish guidelines to help homeowners design roofs that are in character with the local architecture style. If a home design is of a particular style it is very important to consider the appropriate form, materials, and detailing of this very dominant element.
When usable space in the attic is desired, roof design, space planning, construction technique, and zoning and building code requirements all collide in a complex jumble. Designing usable attic space is a truly three-dimensional problem, especially in remodeling work. Properly done, however, a room up under the rafters can be a very special place; a private area for meditation, or a bedroom with great views over the neighboring homes.
Dormers may puncture the roof plane to add character and detail to the exterior and allow light and air into the “attic”. That was the case in my first home office, in the attic of an 1890’s era home in a historic district. I had to duck to clear the rafters at the top of the 26 steep stairs up from the street level, but once at my desk, I had a wonderful view of downtown skyscrapers only a few blocks away.