Armed with only her expertise, lots of patience, and a laptop, architect Wendy Welton makes four-hour house calls. She spends the time discussing and designing additions and remodeling projects for her clients' homes, a task that is much more rewarding since she began using 3-D CAD software a year ago. Before that she would draw plans by hand.

“Software lets people who can't see traditional architectural designs understand what's going on. It provides a higher comfort level for the homeowners and provides me with instant feedback,” Portsmouth, N.H.-based Welton says.

CAD software allows architects, builders, and remodelers to quickly and easily draft house plans. All of the pieces culminate in a high-definition computer model that can be viewed from a variety of perspectives. It's especially popular with small home building and remodeling firms that use it as a show-and-tell tool for their clients.

Most programs also offer libraries that let pros import brand-name products into the creations, from surfaces to appliances to siding to dormer windows. And with each new upgrade, the software is getting faster and easier to use.

“What used to take an hour to draw by hand now takes 10 seconds,” says David Merrick of Kensington, Md.-based Merrick Design and Build.

This is because software makers are “moving from a graphical drafting paradigm to a modeling paradigm,” says Robert Anderson, vice president of integrated products for Nemetschek North America, maker of VectorWorks software, which claims about 200,000 users worldwide.

Instead of having to draw house segments piece by piece, newer programs offer components with built-in features such as pre-formed dormer windows. According to Anderson, this building information modeling (BIM) concept is the future of CAD software because it frees pros from having to slowly create drawings for each separate element of a house.

Josh Rosenthal of Rosenthal Homes in Potomac, Md., uses Chief Architect as a design tool for small renovations and as a marketing/visualization tool with his custom home clients. Chief Architect claims more than 1 million users.

“Builders and clients both get frustrated if you don't have a shared language,” Rosenthal explains. For example, the builder says the software comes in handy when he uses a term or description that his clients don't understand—at times like this, the highly detailed images he creates on the computer are truly worth a thousand words.

What's more, design software allows pros to see how much material they'll need and how surfaces and products interact, says Anderson.