Estimating the labor for any phase of construction can sometimes can be tricky. Depending upon where you live, current economical conditions and just what the market will bear, these estimates can vary greatly from one area to another and at different times. This is the main reason most responsible estimators limit estimate validity for 30 days, and in some cases, less. Estimating the labor to install glass is likewise limited. While there is no exact formula for this rather inexact process, it is possible to establish close estimate ranges to at least be pretty close to the final cost.
Calculate the total area the installed glass must cover. Measure the openings precisely, width and height. Count the number of openings; then, multiply the number of openings times the total area to be covered. This is the total figure for the amount of product, with the precise sizes, you need. It is also the key figure for estimating installation cost.
Consider the phases of the installation process. First, look at window opening preparation, and the time preparing the openings will require. Include the cost to frame out the openings and install flashing. Address any special installation framing requirements involved. Assign a time allotment to this first phase and assign a money cost for that time.
Look next at the type of glass that is to be installed and the amount of work involved for that type. For instance, if the glass is in the form of single self-contained units already encased and framed, count only the time it takes to set in each unit, nail and shim it into the openings. If the glass is in the form of panels which must be fitted into installed metal framing and sealed on site, you must account for the time to construct the frame, mount the framing, install the window and the seal. Estimate and total this time for each opening or window.
Add in the time and cost for cleaning the windows and for job site clean-up. Tally and include this cost in your total cost estimate, or think about doing it yourself. Do it yourself only if you can save money after paying yourself and your help for doing it, and most importantly, if you are willing to accept the replacement cost of any windows damaged or broken either by the previous installer who did not “see it” or one of your helpers. If you are not willing to accept the costs, do not take on this final phase of the install.
Total all costs to get a very close estimate of installation. Use this figure to shop for installers. Do not tell them what your total cost figures, but let them tell you what they will do the job for after you have given them the essential information.