Understanding your attic space options and limitations is essential to maximizing its living space. The most important factor in designing attic space is determining the exact dimensions of the existing interior space and being able to calculate the finish dimensions after floor buildup and ceiling build down. As you look at your attic space and dream of its potential, there are a few things to consider:
- Windows. Skylights can bring in much needed light without the expense of dormers, or pop-out windows.
- Exit. Incorporating egress, or an emergency exit, is highly recommended for the space, even if you don’t plan to use the attic as a bedroom. Any time spent in the attic space without egress is “borrowed time.”
- Rafters. Spending the time and money to even out the surface of the interior rafters is a must. Roofs are built to be even on the top of the rafters, not bottom. Hips and valleys make the bottom side very uneven. Increasing the rafter depth or building down the rafters decreases headroom and floor space, but it ensures a clean ceiling line and all the odd angles in an attic space. It’s expensive but necessary. If not done, it can result in improper attic ventilation and insulation, drywall and tape problems, and a very poor finished look.
- HVAC. HVAC systems must be extended or, better yet, zoned for an attic space. They will be much warmer in the summer and winter than any thermostatically controlled floor below it.
- Stairs. The space taken away from the floor below the attic to build a proper staircase to the attic must be considered. If an area above the home’s existing staircase can be utilized, that is the least invasive and may remove only a closet from that floor. In some instances, however, it means an entire bedroom is taken away.
- Walls. From a design perspective, knowing where to stop the slope of the roof and come down with walls is quite the challenge. Closets are a good point to make this transition. But with the continuing slope of the roof, it’s important to know just how “low you can go.” Traffic patterns and furniture placement is extremely important otherwise those valleys can be head bumpers.
- Floor Support. Support for the attic floor must be calculated correctly for the live-load requirement. Most ceiling joists are 2 x 6, but they are only carrying the plaster or drywall finish. Once an area becomes living space, the load calculations change completely. If the load is not supported, the ceilings below the attic will show wear and tear. Plaster will crack, and drywall will start with nail pops and eventually tape joints will crack.
- Collar Ties. Collar ties, or the wood that horizontally connects opposite roof rafters, are another challenge. They are typically set at two-thirds the distance from the ceiling to stiffen the roof structure. They may not be located at ceiling height, and it’s assumed they could be moved up. This two-thirds distance is the maximum height a collar tie can be placed. Above that height, the roof structure is marginalized. The only proper way around this dilemma is a heavier ridge beam to support the roof load or engineered midpoint walls that will take the place of the collar tie.
Without careful planning, both contractor and homeowner can be caught off-guard and unhappy with the results.
