Thanks for your question.
Initially, the effect of the Stadium will be negative, as both traffic,
congestion will increase.The flight path had been in place earlier,
so that has already been factored in.
In a down market, every negative will have a dire consequence.
In an up market, like right now, Buyers over look issues.
Over time, with better Traffic Management and improved City Tax earned income,
the region will prosper.
As Terri noted below, stadiums and sporting events=big business for many cities and can result in some great new opportunities for many in the immediate area.
For those in residential housing complexes, however, traffic, congestion and noise can be the result of new stadiums and events housed in the stadium, so its understandable that you're concerned about the impact on you and your home. To determine how the stadium will affect you, the California Environmental Quality Act, also know as CEQA (pronouced "See Kwa") requires all large scale improvements to be evaluted by experts and for those results to be published in a document that you can obtain called an "Environmental Impact Report" or EIR, for short. The report contains information about traffic, noise, pollution, lights, and general effects of the new building on nearby businesses and residences. If you contact the City of Santa Clara Planning Department, they should be able to direct you to the location of the EIR on their website or can make the report available to you via copy or disk.
As to how such improvements will affect the value of your home, only time will tell on this one. Depending on how buyers perceive the improvement --good or bad--the value of the home will certainly be affected by that perception. We'll have to see how this all appears to buyers in a few years.
Thanks again for the question. Good luck!!
When the Shark stadium was built in San Jose it created jobs and brought money to the downtown. New businesses opened up and that brought cash flow to the city. In turn that cash flow allowed for city spending and funding for housing. People purchased high rise condos and the property tax income flows right back into the city. It changed the surrounding area of downtown for the better.
Let's see if the same circle of economic life plays out in Santa Clara. One should hope so.