NEWPORT NEWS, Va. - With a little help from elves who paint and put up trim work, Wray Emerson may be giving his wife, Sandra, and three kids a new house for the holidays. If not then, at least as a New Year's gift, he says.

"My wife keeps asking me when it's going to be ready," he says, laughing.

Sandra's patience may be wearing thin - he started building the house five years ago - but her wait will be worth it.

The house is big but affordable in construction costs and hopefully easy on heating and cooling bills. Termites will have a hard time attacking it, and it's built above flood level.

"I'm building this thing on a shoestring," says Wray, 55, owner of F.W. Emerson Masonry, a family business his father started in 1949. In addition to cutting costs by doing much of the work himself, he received help from his brothers, Carol, Larry and Garry, brother-in-law David Westcott and contractor friend Dan Gwinn.

Even with help from family and friends, he's making his costs, about $230,000 for the house alone, stretch pretty far. The two-story brick structure encompasses a generous 4,000 square feet. That means he's building it for less than $60 per square foot, which is below the typical $100 to $150 a square foot most new-construction homes costs nowadays.

The price does not include the cost of the land: an acre with 300 feet along Back Creek in Yorktown, Va. The Emersons were living in a small house already on part of the property, but Hurricane Isabel flooded and ruined it. After the storm left them homeless, they moved into a family home just a stone's throw across the creek.

Wray believes he will save substantially on heating and cooling bills because he used about 1,400 AAC (autoclaved aerated concrete) blocks instead of two-by-four wood studs to frame the house. His blocks are large - 12-by-24-by-8 inches compared with a standard 8-by- 8-by-16-inch cinderblock. Other sizes are available. They are made with a mixture of cement, water, sand and limestone. When aluminum powder is added, the mixture turns into a "foamed" concrete that first is made into large slabs, then sliced into solid blocks. They then are cured in a pressurized steam chamber, or autoclave.

The manufacturing process fills the blocks with thousands of tiny air bubbles that produce above-average insulating properties: an R27 value compared with R13 for standard insulation in a wood-framed wall, he says. Insulation products are measured in R-values; the higher the number, the better.

"Those big old blocks also float," says Robert Criner of Criner Remodeling, also in Yorktown.

Criner travels the country giving construction seminars at building conferences, and he's familiar with the positives and negatives of the aerated concrete blocks.

"It's a different kind of building, so you have to learn how to build all over again," Criner says. "But, you end up with a very strong, tight house."

The aerated concrete blocks are secured with thin-set mortar; they cut easily using only a handsaw or any woodworking tool. With brick added to the blocks' surface, the house has 12-inch walls.

"There is no insulation in this house because this is the insulation," he says, patting the home's outside wall.

There's also minimum wood in the house, especially at the ground level, meaning little potential for termite problems. Wood is found only in the interior walls, roof and upstairs dormers.

For the subfloor downstairs, Wray used the AAC material fashioned into 900-pound floor panels that are 2 feet wide and 18 feet long. Rebar, metal rods for reinforcing concrete, run around the perimeter of the house, into the concrete foundation footers and between the 49 floor panels, helping tie everything together for added strength. The blocks, panels, mortar and support lintels to go above windows and doors cost him about $12,000, including freight. That's about 5 percent more than what wood framing would have run, he estimates.

About 3,000 feet of radiant heat tubing snakes through the 1-inch concrete slab poured over the floor panels. Hot-water radiant heating will warm the downstairs, while a heat pump will take care of the rooms upstairs. The radiant heat system for 2,200 square feet on the first floor was about $8,000.

"My brother-in-law says he thinks I'll be able to heat this house with matches," Wray said. "I hope so because I've tried to make this house very energy efficient."

Fast facts

Name: Autoclaved serated voncrete (AAC) building products

How it's made: Mixture of cement, lime, water and sand is mixed and placed in a steel mold; a tiny amount of aluminum powder is injected to help form millions of air bubbles, causing the mixture to expand much like how bread rises. These millions of tiny air cells provide outstanding thermal insulation, helping reduce cooling and heating bills.

How it's good: It insulates against heat and cold; resists fire and high winds; absorbs sound; will not rot or decay.

How it's finished: Surface it with stucco, thin brick facing, tile, siding materials or paint. Floors can be carpeted, tiled or finishing with wood flooring.

Learn more: Visit the Autoclaved Aerated Concrete Products Association online at www.aacpa.org for a map and list of suppliers and producers nationwide.