Good question, /u/hampsterman22. Let's talk about it.

During the 17th and 18th centuries in New England, timber frame construction was the method of choice for homes. Sometimes called post-and-beam construction, the Historic American Buildings Survey/Historic American Engineering Record describes it as "a form of carpentry which involves taking large pieces of wood and joining them together with woodworking joints, using mortise-and-tenon construction, without metal construction such as nails. Wooden pegs, bents, braces, and sometimes trusses are employed. Many types of colonial houses can be considered to be timber-frame houses, including saltbox houses."

Think of a timber-frame house as a log cabin where the logs have been squared off and worked somewhat before being used in construction.

Saltbox houses are a specific type of timber-framed house that started appearing in New England about 1650. HABS/HAER defines them as "frame houses with two stories in front and one in back, having a pitched roof with unequal sides, being short and high in front and long and low in back. The front of the house is flat and the rear roof line is steeply sloped. The sturdy central chimney is a simple but effective focal point."

These houses were simple, functional and unprepossessing, making them perfect for the attitudes of the time.

Thanks to HABS/HAER, we've got good records of what these houses are like. Since 1933, the Survey/Record has been cataloguing historic homes and buildings. Even if the buildings have since been torn down or destroyed, we know what they looked like and how they were made.

Since all homes are different, based upon the needs and desires of the homeowner, let's talk about one in particular. This is the McIntire-Garrison House in York County, Maine. It was built about 1685 and is a pretty nice (albeit somewhat large) example of a New England timber-frame house.

It's two stories tall and has a basement. Its foundation and basement are stone, while its walls are "oak and pine timbers eight inches thick, squared and dovetailed with sloping surfaces in the joints to shed water." There are fireplaces on both the first and second floors. The sides of the house are clapboarded and shingled today, but that's a later addition.

The house was designed not just as a living space, but as a blockhouse. On Feb. 5, 1692, it served that purpose when a party of French and Indians raided York, Maine and burned the entire village. This house was the only one that survived.

Now, let's take a look at a cross-section of the house to measure its insulation. By modern standards, there isn't any insulation. The home's walls consist of 7 1/2-inch thick hewn logs. On the inside are plaster walls and on the outside are clapboards — but again, those were not original.

Now, we said that there isn't any insulation by modern standards. That doesn't mean the home isn't insulated at all — just minimally so. A material's thermal resistance is measured by its R-value. In a solid log wall, the R-value for wood ranges between 1.41 per inch of thickness and 0.71 for most hardwoods. (Technical information here: http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr190/chapter_04.pdf) White oak is a hardwood with an R-value of 0.75 per inch. Given that the walls of this house are 7.5 inches thick, we get an R-value of 5.625. That's on a blank wall with no windows or doors. If windows or doors are involved, the R-value drops significantly.

Let's compare this value with a modern home. If you were to use 8 inches of fiberglass batt insulation today, you'd get an R value of 25. Use high-density batts, and you'll get an R-value of 30. That's a huge difference!

In fact, the Garrison House wouldn't even meet code standards in a place like Philadelphia today. There, the building code requires R-13 for walls and R-38 for ceilings or roofs. Newer codes require R-20, and a lot of green builders shoot for R-40 for homes and R-60/70 for roofs.

Wow, thank you for the detailed response!!!