My favorite brand of residential exterior doors is Thermatru for their durability, insulation, and weatherstripping. Andersen also has an extensive line of pretty good doors.
http://www.andersenwindows.com/
But I sure do like to see it when it’s possible to get fancy with crafted wood doors. Wood is not a bad insulation either, and stylish.
These folks make pretty good steel bulhead basement doors.
To see what a well engineered window looks like, study the architectural details at the Marvin Window website. I always feel safe recommending Marvin.
There are many other window companies with different prices and styles. You need to browse through and find what you like and what fits your budget. Ask local suppliers for prices on individual windows. You can bargain for a discount when you order many windows at once later.
http://www.andersenwindows.com/
http://www.integritywindows.com/
Here are the qualities of a good window. 1. No air leaks. 2. Exterior surface will endure in heavy sun and rain. 3. Interior finish fits my taste. 4. The hardware is durable and firm. 5. The window opens up firmly but smoothly. 6. There is no visible caulking, but clean corners. 7. The style of the window fits my house.
The best window on the market offers an R-3.57, and most do not exceed R-2.5. So you can see that most of the heat loss will occur as heat escapes out through the windows. At the same time, when the sun is out, the windows provide a terrific source of solar heat. The ratio of window area must be balanced to the optimal ratio for your climate.
In Maine, the ratio of floor area to glass area should be roughly 10 percent glass. If the floor area is 1000 square feet, the glass area should be about 100 square feet, which might allow ten windows, including glass doors. Every room in the house needs a window, usually large enough to qualify as a fire escape egress. All the rest of the glass area should be located on the sunniest walls of the house.