You can submit additional information on Trulia's system by clicking on the "Too high? Too low?" link listed under the value estimate. Zillow has a similar capability to update info.
The value you are seeing on Trulia is being generated by an "AVM" (Automated Value Method) application which just looks at "the numbers" of each home (primarily square footage) and makes a rough estimate of value based on adjacent sold properties. Generally, a RealtorÂ® CMA will be more accurate than an AVM, and an Appraiser will be more accurate than RealtorÂ® CMA.
This blog post goes into more detail on these three options:
Zillow & â€œDartsâ€
Hopefully someone from Trulia will respond to help you login to the site. But, in the meantime, please know that whatever value shows up here or on any other Web site, in no way affects the actual value of your home. The best way to know the value is to have an appraisal, or to have an agent run recent comps. But, I know it is nice to see the work we've done on our homes reflected.
If you ever put your home on the market and a lower value showed, no appraiser or buyer's agent would use a consumer web site to determine value for an offer or for the lender.
Cory La Scala, REALTOR