Need More Space? What it Takes to Add a Loft

Until recently, “loft” was a four-letter word to much of the interior design world.  The very concept called to mind visions of dingy college dorms with rickety loft beds made from splintered doors and rotted wood.

But thanks to a growing movement in “cozy” living, the loft has become an invaluable solution for homeowners desiring more space for an office, gym, theater, storage area, extra bedroom, without shouldering the higher cost and demolition of architectural add-ons. With necessity, innovation has followed, and today, the modern loft has risen to new heights in style and sophistication.

From ground floor to full attic conversion, here’s what it takes to create your own loft:

  • Time: Depending on the scale and scope of your design, installing a loft could take as little as one day to as long as three weeks.
  • Cost: Again, scale and scope range from a few hundred dollars to several thousand.
  • Permission: Across the board, building code permits and/or homeowner’s association approval is critical before starting any renovation project.

Choose from the range of loft designs and their corresponding requirements:

Raised Platform

This option is ideal for small studios or wide open industrial living spaces. The overall concept consists of a single, raised platform constructed in the middle of a room or corner area. Built into the platform are cabinets, drawers, and shelves to provide additional storage, and a small incorporated staircase leading up to the platform base. There, you can create an entire living space with mattress, bookshelves, end tables, and seating.

From the ground, this elevated platform creates a multi-dimensional visual experience, adding levels to an otherwise uniform interior.

Prefabricated Loft Kit

From Home Depot to most home design websites, you can buy an already packaged prefabricated loft kit, or design your own and have it delivered for assembly. This is a popular choice for children’s rooms, as they provide a modular bunk experience.

Ceiling Loft

Wondering what to do with that wide gap between the top of your shelves in your walk-in closet or above the cabinets in your kitchen? You could decorate it with colorful glass bottles and flower arrangements. Or, you could convert that space into a low-level loft where holiday guests can crash after one too many eggnogs.

In some cases, you may opt to lower the existing ceiling height to add more head room in the loft above. Either way, building that space out is not recommended until consulting a structural engineer. The reason being, the existing ceiling was not designed to support a live load and may require the installation of new floor joists or specific underpinnings. Entrance into the area also requires a fixed ladder or fire-approved staircase.


By definition, a mezzanine is an intermediate floor between two stories in a building. The perfect blueprint for this type of loft is the suburban home of the 1990s, where one feature dominated: the enormous two-story living room with towering cathedral ceilings and two parallel walls of windows. These rooms, while impressive and craning, quickly became known as notorious energy sucks and space wasters. The perfect solution is the the mid-level mezzanine loft.

In order to break ground on this design project, it’s absolutely critical to consult building codes and acquire necessary permits, especially if you live in a semi-attached townhome or condo. Illegal loft conversions are not just costly, they can be dangerous as well. Additional details to know:

  • Building a brand-new floor within the thin air of an open living room starts by securing a frame to the wall with anchor bolts.
  • The existing wall joists may require underpinning or even steel or timber beams to support the new load.
  • Once the frame and floor is in place, the existing windows will need to be converted from fixed glass picture windows to egress, openable frames, in case of fire. Additionally, tempered glass may be required depending on how much room there is between the floor and the bottom of the window.
  • The loft frame will require thermal and sound insulated drywall.
  • Added ductwork may be needed to provide conditioned air to the loft.
  • A new electrical panel may be required if it’s not feasible to run a circuit to the main panel .
  • Half-railing walls that look out over into the main living room must be fire-resistant and comply with building codes

Attic Loft

This is most cost-prohibitive loft option, and yet also the one with the most return on its investment. A huge benefit of this design is the already existing roof and subfloor, two huge expenses of any rebuild.

Here are the need-to-know costs and considerations of the complete attic-to-loft conversion:

“Rule of 7”

The first step is to make sure your attic satisfies the “Rule of 7,” which mandates the space be 70 square feet in size, with no less than 7 feet in any direction. So, even though a 5-by-14 foot space equals 70 square feet, it doesn’t qualify as one of those lengths is under 7 feet.

Also included in this rule is the requirement that at least 50% of usable floor space have a ceiling height of 7 feet or more.


Another strict code of attic renovation mandates at least 8% of usable floor area must be glazed, as in contains windows. Additionally, at least half of those windows must be egress, openable,  to provide a safety exit in case of fire.

Temperature Control

Building codes require that live-in attic spaces be able to maintain a temperature of 68 degrees Fahrenheit at any given time. The first step to achieving this is sealing all and any cracks, gaps, and creases between window units, doors, walls into unfinished parts of the attic, ceiling fixtures, the chimney, light switches, and so on. After that, homeowners may decide to regulate temperature via a low-cost option of ceiling fans and window AC units or the higher end option of a fully functional HVAC system.


A critical component of temperature control is proper insulation, which not only benefits the attic space, but the entire home’s overall resistance to mold, moisture, pests, water vapor, and sound.


A basic roof inspection, which averages $250, must precede any attic renovation, as worn shingles or deteriorated flashing are certain to cause leaks into the lower living area. Costs beyond that will depend on the type of issues found. Inside, it’s recommended the roof be supported by A-shaped rafters over the less-substantial W-shaped trusses.


Depending on the severity of mold issues, remediation can cost between $1500-$10,000 for the most critical cases.


Putting in drywall, installing trim and moldings, painting, and any other treatments.


Ordinarily, an attic floor is built to hold dead loads, as in stationary furniture, boxes, and storage. First and foremost, the new base must be reinforced with added joists and insulation to support moving weight. 


Building regulations require that all living attics be accessible from the lower level via a staircase. The pull-down rope ladder isn’t code compliant. Also, the staircase must provide a minimum of 7 feet in headroom the entire walking length of the stairs.


If you decide to add a fully functional bathroom to transform your attic into an in-law suite, expect to pay an average $1500 to retrofit plumbing. Also, choose to build the bathroom near the existing DWV system to reduce demolition needs.


The final step to converting your attic from a dark cave into a bright livable space is electricity. Expect to install a new electrical panel to support the increased load and mounting any recessed lighting, ceiling fans and other fixtures.

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