Basement and Attic Remodels
/AN INEXPENSIVE WAY TO CAPTURE ADDITIONAL LIVING SPACE
Perhaps you’re wondering what it would take to convert that attic space your teenager has monopolized into a real bedroom? Or maybe you’re curious if it’s possible to transform the basement into that home office you’ve been dreaming of? You’re not alone. Attic and basement conversions are two of the most popular remodeling projects for good reason: dollar for dollar, capturing existing space that already has floors, walls, and a roof offers savings and often makes more sense than a new addition to a home. Compared to an addition that needs new foundations, framing, and a roof, an attic or basement may only need minor structural modifications and mechanical extensions to make the space habitable.
How does one determine if an attic or basement is worth converting? The same building codes that apply to homes apply to livable basements and attics: proper ceiling height and room sizes must be met, a legal stairway to the area is required, the space must be insulated, heated, ventilated, and/or cooled, and if you’re converting space to bedrooms, fire exit or “egress” windows must be provided.
So the first question is if the basement or attic is the right size for what you need. Is the ceiling at least 7' high and can the area accommodate minimum room requirements? In general, the minimum size for habitable rooms is 70 square feet and for kitchens, it’s 50 square feet. 7 feet is the minimum width of a bedroom and a small half bath might need 3' x 6' where a full bathroom wants about 5' x 8.’
Vertical circulation is the second most important element to consider - will you need an additional or expanded staircase and where should it go? Most existing attic and basement stairways don’t meet current building codes which have very specific dimensions for treads, risers, handrails, and landings. Legal stairs, unfortunately, require more space than most people initially plan for.
Ideally, new stairs should be located close to a circulation route on the home’s main floor. If possible, build a generous staircase, omit doors and make new stairs a central feature of both floors. A stairway is an exciting design element, so flood it with natural light, windows, or skylights. In some cases, stairs might be the only source of natural light for an attic or basement remodel, so maximize this potential. Good artificial light (a large pendant, some wall sconces, or even a fanlight) will also enhance the stair experience.
BASEMENTS
The easiest space to convert is a basement with an existing floor and walls. As long as it has the minimum ceiling height, the only thing you’ll need to evaluate is the structural condition of the floors and walls and if it has sufficient space to meet the requirements for habitable rooms. In hilly landscapes, another way to gain additional liveable area is to create a basement level from a tall crawl space.
Structural Issues
If the basement your converting has a concrete floor, check to see what condition it’s in. If it’s old, cracked, not very level, or water is present, it might need to be replaced. If the floor is wood-framed, check for deflection. If the floor sags, isn’t level or has settled, it might need to be strengthened. Look at basement walls for cracks and signs of moisture, especially if the wall is below grade.
Waterproofing a basement is a critical part of its conversion. If the space wasn’t originally built to be inhabited, one can expect water intrusion through walls and floors. A few basic drainage techniques are essential for habitable basements: slope the grade away from the house; add a french drain to the exterior of the basement’s walls, and add a protective membrane to the exterior face of the concrete.
Architectural Opportunities
A well-lit space won’t feel like a basement with generous lighting. If the basement is above ground, add as many windows as you can afford or energy codes allow. If there are no other options, a well-designed electric lighting system can make a basement quite pleasant. Below-grade basements are often quite cool and might not need anything but operable windows. However, habitable basements need to be ventilated and if windows aren’t possible, mechanical venting will be necessary. Often worth their expense to gain natural light and ventilation, window wells are delightful features that enhance interior spaces.
Radon testing is especially critical for basement conversions. Radon is a radioactive gas that comes from the natural decay of uranium found in nearly all soils. Your home traps radon inside, where it can build up. Any home, new or old, with or without basements, may have a radon problem. Test the area before you begin the renovation.
Since the most common complaint about basements is that they’re always cold, consider installing a direct-vent fireplace. A bargain for the ambiance they add, these inexpensive devices are really nothing more than wall heaters gussied up to look like a fireplace. Another way to take out the chill is an electric or hydronic radiant floor heating system, expensive, but the comfort they add is priceless.
ATTICS
Providing legal headroom is typically the thorniest problem in attic remodels. The easiest attics to convert have a high ridge beam over a large area (think old Victorian homes). The minimum ceiling height must extend over a floor area that meets your minimum room size. For example, if you’re adding a bedroom, you’ll need at least a 7' x 7' floor area with a ceiling height greater than 7 feet.
If an attic’s ceiling height needs to be raised, options are available. The entire roof (including the ridge beam) can be raised or only a portion of it may be raised. Adding dormer windows are another great way to increase ceiling height.
Structural Issues
One of the most common oversights in attic remodels is the extra structural loads that are added to the house. If an attic is remodeled for living space, it will transfer additional weight to the walls and foundations below. This additional weight needs to be supported by existing walls and foundations. In contemporary homes, the existing structure can usually handle additional attic loads. In older homes, check with a local Engineer to make sure that the new attic will be adequately supported all the way to the ground.
In most cases, floor framing will be undersized as it’s only meant to support the dead load of the ceiling below it. Adding larger floor joists between the ceiling joists solves this dilemma. If head height is restrictive, it might be possible to add beams below the ceiling joists (on the ceiling of the floor below) to lessen their span. Depending on the vintage of the home, existing roof framing, or rafters, might need to be strengthened. Rafter or cross ties, often at eye level in attics, can be tricky to eliminate. The easiest solution is to reconstruct the tie in the floor framing space. Beefing up the size of the roof rafters and/or ridge beams also eliminates cross ties.
Architectural Opportunities
Venting built-up heat is usually necessary in attics. Operable skylights are a good way to vent the space as well as to get natural light. Inexpensive solar tubes are another way to do this. Reverse-cycle ceiling fans are great devices to install in converted attics for both summer and winter. Add dimmable lights to the fans and you’ve solved a lot of your venting and lighting needs.
Converted attics can be magical spaces: intimate and quiet with sloping ceilings and lovely vistas. Look for special orientations and design the new space toward them. If there isn’t a view, think about adding a unique window somewhere in the attic. If your budget allows, consider adding a balcony or deck, angled toward the sun.
ADDED VALUE
If you’ve determined that your attic or basement has conversion potential, talk to a knowledgeable local building professional. They will explain how your particular space can be transformed into a liveable area while still meet local building codes. And since your addition has saved a lot of money on structural costs – and added value to your home -- you might consider splurging on quality finishes. Even teenage bedrooms and home offices look better with nice flooring and efficient LED lighting.
