I have added some very useful resources below for Real Estate websites, that I have found very helpful. I am currently developing a PHP based program that will be extracted geo location data for offices of interest in the UK and USA. The aim is to provide a resource to assist real estate customers.

1. http://www.london.gov.uk/
2. https://www.gov.uk/government/organisations/foreign-commonwealth-office
3. http://www.dre.ca.gov/
4. http://www.theguardian.com/business/realestate
5. http://www.azre.gov/
6. http://realestate.utah.gov/
7. http://www.justia.com/real-estate/
8. http://www.theofficeproviders.com/
9. http://www.reaa.govt.nz/Pages/default.aspx 10.https://www.arello.org/