GONE ARE THE days of sketching furniture plans on the backs of napkins: A slew of free online interior design programs can now do the heavy lifting and deep thinking for you. With just a few clicks of the mouse, anyone can feng-shui their living room, plan a move or build an addition.

“These software packages are great for homeowners who want to work on furniture layout and rug placement,” says Lisa Adams, founder of D.C.-based Adams Design Inc. (3913 49th St. NW; 202-333-1220; Adamsdesign.com). She cautions, however, that the measurements in online design programs aren’t always exact, and virtual floor plans often don’t account for details such as lighting and electrical wiring. For any work that might require permits, Web-produced designs can’t compare with blueprints created by professionals, says Adams, who also teaches residential interior design at George Washington University.

The average condo- or townhouse-dweller could certainly find one of these programs useful, though. So, grab your laptop and start dreaming.

» FLOORPLANNER (Floorplanner.com)
Floorplanner’s basic program lets you create a blueprint for one house, view plans in three dimensions and share your designs for free.

Unlike some other sites, sign-up is a breeze, since Floorplanner lets you log in with Google, Yahoo! or OpenId usernames and passwords. Once in Floorplanner, select “My first project,” click on the “draw single wall, line or dimension” feature in the Construction pane, and start creating your space.

Floorplanner’s tools are very flexible and easy to use. You can construct rooms line by line and customize floor plans to exact measurements. To plot out an entire apartment or house, simply add adjacent rooms.

The site’s “library” of furniture contains plenty of elements — fireplaces, sofas, rugs and more (inexplicably, there are an overwhelming number of staircase styles to choose from) — making it possible to accurately represent every angle of your abode. To position these elements on a floor plan, simply drag and drop; double-click to enter dimensions. You can also block off space for boilers, radiators and water heaters.

Best for: Gung-ho users ready to break out their measuring tapes as soon as they’re done with the Web site. Also great for those decorating unusually shaped rooms.

Coolest feature: While Floorplanner allows you to design in only two dimensions, its 3-D function will reveal a more lifelike model of your floor plan once you’re done.

» BETTER HOME AND GARDENS ARRANGE-A-ROOM (Bhg.com/decorating/arrange-a-room)
The Better Homes and Gardens Arrange-a-Room program lets you select pre-designed layouts to customize by clicking and dragging to reshape rooms.

The process is easy and intuitive, but detail-oriented users will be annoyed that they can’t provide their own measurements. Another drawback: The space for designing a room is very small, and though you can draw walls beyond the edges of a room, the program doesn’t let you zoom out to see everything.

Unlike other sites, though, Arrange-a-Room allows you to customize furniture and floor colors. Basic items (office, bedroom, living room, etc.) are available to furnish each room. Drag and drop bookcases and dressers onto a floor plan, and adjust the furniture measurements or colors by clicking on the object. Little tweaks such as choosing armchair colors help give a full sense of how a finished room might look.

The program’s real downside: Too much sign-up rigmarole, involving repeated requests to purchase Better Homes and Gardens and enter a lot of sweepstakes. By the time that’s finished, there’s no link back to the Arrange-a-Room page, so you’ll need to backtrack to the original page.

Best for: Amateur planners hoping to get a feel for a room’s look without the distractions of nitty-gritty details such as actual measurements.

Coolest feature: Users can create up to 25 rooms for free — perfect for recessionistas with big dreams.

PlanningWiz 3
» PLANNINGWIZ 3 (vV3.planningwiz.com)
Users of all stripes can build rooms on PlanningWiz 3. Those who want precise blueprints can lay out rooms from scratch by inputting specific dimensions. The less exacting can alter pre-fab floor plans with the program’s wall tool.

Customizations such as changing colors and resizing are not immediately intuitive — it took some clicking around to discover how the tools worked.

Although the learning curve is steep, the program’s not impossible to master. Once you get the hang of it, you can delve into the minutiae as much — or as little — as you like.

An extra bonus: Planning Wiz reliably saves customized plans for later.

Best for: Low-tech users with low-tech aspirations, high-tech users with high-tech aspirations, and anybody in between.

Coolest feature: Planning Wiz provides the easiest wall-editing function of the sites featured here. This might seem like a minor detail, but after playing with Arrange-a-Room, you’ll definitely understand.

Icovia Space Planner

Recommended to customers by furniture retailers such as Thomasville (Thomasville.com), Storehouse (Storehouse.com) and Casual Designs Furniture in Berlin, Md. (Casualdesignsfurniture.com), Icovia Space Planner is a professional paid service with a $29-per-month price tag. The company offers a full-featured free test drive on its Web site, however, which is well worth a look.

You can begin by choosing a preset plan for anything from a master bathroom to a kids’ playroom, or by creating your own plan by drawing walls or entering room dimensions. Preset plans can be easily altered for additional walls or different measurements.

Other sites should take a cue from Icovia’s “fit to view” tool, which allows for easy zooming in and out — great for focusing on floor tiles or an ultra bird’s-eye view. An extra-cute touch: The master bath layout includes a pair of slippers on a bathmat (since, you know, that’s important to factor into your design plan).

Best for: Since it charges for regular use, Icovia isn’t a good investment for casual users. Try the free versions at the Thomasville and Storehouse Web sites, instead (even though these lack the colors and details of Icovia’s test drive).

Coolest Feature: Icovia offers a text tool that lets you annotate the floor plan — go ahead and label your toilet if you want to.

iVillage Design a Room
» IVILLAGE DESIGN A ROOM (tinyurl.com/ysagt4)
If you just want to fantasize about color and style, visit iVillage Design a Room.

There’s a lot going on here. The first page appears to have so many options that it’s hard to know where to start. The real secret is that there are a lot fewer options than it seems.

Begin by choosing a type of room (kitchen, family room, bedroom) and a style. Not sure whether you’re “casual country” or “global fusion”? No problem. Click through Design a Room’s options to see what looks appealing. But here’s the catch: While the site lets you choose cabinetry and counter tops, it doesn’t let you choose furnishings or accessories.

What Design a Room provides is umpteen choices for flooring and wall colors. Choose your desired combo, and the site renders an image of the room with your picks.

It’s a great way to generate new ideas, even though Design a Room lacks the flexibility that would let you truly make a room your own.

Best for: Users interested in wall and floor colors, and pretty much nothing else.

Coolest feature: Wall color and flooring combinations seem endless. Ever wondered what puce paint would look like with mahogany flooring? You don’t want to know — but you can!

Written by Express contributor Roopika Risam
Photo courtesy Floorplanner, Arrange-A-Room, Planning Wiz 3, Icovia, iVillage