Whether you building a new home or remodeling an existing home, when it comes to windows there are a few things you will want to know about them. There are differences between them. You will want to think about efficiency. Most of the heat that is lost or gained is through windows, doors, next to the attic, which is the number one place.
What are some differences between casement windows and double hung windows? One thing is that double hung windows are not as air tight as casement windows. The wood on double hung windows can also block your view.
You will want to check what the rating is on the window from The National Fenestration Rating Council (NFRC). There should be a label on the window that will help you compare the efficiency between windows. There is the R-Value, that you will want to choose the highest rating in this and lowest infiltration loss. The U-Factor measures how much heat will escape from the window. You will want to pick the lowest U-Factor.
Solar Heat Gain Coefficient (SHGC) tells you how much solar heat is prevented from getting in. You want a low number on these as well. Visible Transmittance (VT) measures the amount of light that can pass through the window. Ultra violet protection (UV) shows how much sunlight can pass through the window that will possibly damage or fade furnishings over a period of time.
You will also want to be sure to pick window covers that will help keep your home efficient also.