You'll need to call the county assessors office to ask them to adjust the assessed value of the home to include the new guest house. If you have lots that aren't included in the APN you want you'll have to merge the lots together so that they all have one APN. That's not hard to do and I can help outline the process to you. I've done subdivisions and accretion (merging) is simply the reverse process.
As for valuation, an acre in the Country Club area is worth about $1.8 million right now. Your overall valuation would be based on the value of your home plus that land value. If you'd like a more accurate assessment, send me an email or call and I'll be happy to help - no obligation.
This is the problem with automated searches and property "evaluations". Your property is unique and impossible to compare to others without a thorough analysis. If you own the open space lots as tenant-in-common, as you said, I can only assume you own certain fraction of those lots with others and might not be possible to add them to enlarge your lot No. 86.
The secondary dwelling requires another adjustment in value. If you are preparing to sell your properties, it would serve your best interest to contact a real estate agent experienced in marketing unique properties.
If you have any other questions I could help you with, please don't hesitate to contact me.
Coldwell Banker Los Altos Office
Thanks for your post.
Trulia's valuation program seldom includes separate unimproved lots in their valuation even if owned by the same owner because, of course, the lots are separate and there is no requirement that the separate lots be included in the sale of the home. As I look at Trulia's listing for this home, I see that the property lists only 29,000 square feet, so I am assuming that maybe one of the four unimproved parcels may be included in this square footage.
In order for the four unimproved lots to be included in the valuation of the home located at 1907 and 1905 Quail Meadow, you would need to petition the Town of Los Altos for a lot line adjustment to annex the four parcels into the main home parcel. Talk with the Town Planners to see how to apply for this adjustment. Once the adjustment is granted, then the property will show up on all searches as being the larger 49,000 square foot lot.
In the meantime, if you go to your home's description page here on Trulia, you'll see an "edit this listing" button to the right of the address that you may use to make changes to the Trulia listing.
Good luck! And if you ever want to relist your home or need more information about sales in the area, please feel free to contact me!
Grace Morioka, SRES
Area Pro Realty
Tel (408) 426-1616
Listings Starting at 1% for Sellers, Commission Rebates for Buyers!
If you would like me to email you the public county records reports for both your addresses, you may contact me through my Trulia profile. Kind regards.