Value Homes Calculator

When looking for a home previously, I often found myself looking at a home (at windermere, redfin etc.) then immediately checking on zillow if the home is below its estimate.

Since I repeatedly did this, I thought that if zillow had a feature to allow me to see homes that were lower than estimate that might be a handy search feature. It would be great if I can set various thresholds like Kayak to filter results by e.g. 20% below value etc. and run searches.

Looking at Zillow's api - It seems fairly easy to build this:

• Use their GetRegionPostings api to get listings for a region. http://www.zillow.com/webservice/GetRegionPostings.htm?zws-id=&zipcode=98004&rental=false

• Use their GetZestimate api to get zestimate for each listing above http://www.zillow.com/webservice/GetZestimate.htm?zws-id=&zpid=48749425

• Use GetUpdatedPropertyDetails api to get the price of each listing http://www.zillow.com/webservice/GetUpdatedPropertyDetails.htm?zws-id=;&zpid=48749425

• Compute the difference between price and estimate and sort the results.