Windows make up a substantial percentage of the cost of building a house. Many people save money on windows by buying them used from architectural salvage yards and used building materials stores. If your construction plans call for unusually large windows and you don't want to pay a fortune for them, it's possible to build your own. Home built windows probably won't be as heat efficient as professionally manufactured ones, but they will definitely be less expensive.
Collect used windows and pieces of glass and store them in a safe place. Go to yard sales and auctions and keep an eye on the free section of online trading sites like Kijiji and Craigslist. To get free and cheap windows and glass, you need to be ready to take them when they're available.
Design the layout for your windows based on the parts that you've managed to accumulate. Make careful measurements of the floor to ceiling area where you are planning to put the windows. Design large, floor-to-ceiling windows out of smaller windows by fitting them together in interesting ways.
Build a customized framework based on the sizes of the smaller windows that you will be using. Cut U-shaped channels out of both sides of 2-by-4 lumber to create a track into which you can fit the smaller windows. These 2-by-4s will be the framework that holds the entire window structure together.
Assemble the floor to ceiling windows by placing the salvaged windows into their places in the 2-by-4 framework that you've designed and screw the entire structure together using three-inch-long screws. Increase the heat efficiency of the windows by putting a bead of silicone caulking into the U-shaped slots before fitting the windows into them.