Underbuilt-Lot & Teardown Screener
The best redevelopment plays are hiding in plain sight: small, older homes on lots zoned for far more house than sits on them today. This screener scores active Silicon Valley listings against each city's floor-area limit to surface the most underbuilt lots MLS filters never show.
Envelope vs. Existing
We estimate each city's allowable floor area from its zoning rule and compare it to the existing home to measure unused headroom.
Expansion Upside
Low utilization on a sizable lot means room to add square footage, or, for older homes, a scrape-and-rebuild.
Sourced & Conservative
FAR rules are curated per city with code citations; uncurated cities use a flagged conservative estimate, never a false signal.
Most Underbuilt Listings
Filters
Zoning & Risk
$3,088,000
21905 Meadowview Ln, Cupertino
$2,500,000
1321 Cabrillo Ave, Burlingame
$1,699,000
304 Peninsula Ave, Burlingame
$2,960,000
323 Sonora Dr, San Mateo
$1,549,000
1163 Brace Ave, San Jose
$1,295,000
2032 Nunes Dr, San Jose
$1,698,000
2116 Quito Rd, San Jose
$1,688,800
7290 Ventana Dr, San Jose
$1,499,888
684 Mohican Dr, San Jose
$1,649,000
1211 Greenmoor Dr, San Jose
$1,299,000
84 S 5th St, San Jose
$2,388,888
3805 Thrush Way, Santa Clara
$2,168,000
1024 E Evelyn Ave, Sunnyvale
$5,498,000
730 Morningside Rd, Los Altos
$3,498,000
3837 Carlson Ct, Palo Alto
$1,688,000
417 Dianne Ct, South San Francisco
$1,295,000
2351 Valleywood Dr, San Bruno
$2,999,000
75 Chadwick Ct, Millbrae
$1,748,000
286 Puffin Ct, Foster City
$1,195,000
231 San Benito Rd, Brisbane
$1,424,999
891 Calle De Verde, San Jose
$1,599,000
2706 Middleborough Cir, San Jose
$1,099,000
2390 Avenida De Guadalupe, Santa Clara
$2,388,000
376 N Cypress Ave, Santa Clara
$1,088,888
749 Santa Cecilia Ter, Sunnyvale
$1,599,000
435 Nicholas Dr, Mountain View
$1,650,000
1317 Dryden Dr, San Jose
$1,698,000
4847 Lago Vista Cir, San Jose
$2,490,000
1092 Harlan Dr, San Jose
$2,049,000
1662 Saint Anthony Dr, San Jose
$999,000
1409 Hamilton Way, San Jose
$1,225,000
5917 Snell Ave, San Jose
$798,000
18952 Sara Park Cir, Saratoga
$3,280,000
1110 Ridgeley Dr, Campbell
$3,999,500
2184 Chuleta Ct, Los Altos
$3,198,000
771 Lewiston Ct, Sunnyvale
$2,589,000
959 Eton Way, Sunnyvale
$2,818,888
831 Shetland Pl, Sunnyvale
$2,798,000
3633 Vireo Ave, Santa Clara
$4,298,888
1260 Grant Rd, Los Altos
$995,000
352 Holly Ave, South San Francisco
$3,498,888
772 Knoll Dr, San Carlos
$1,398,000
3809 Colegrove St, San Mateo
$2,385,000
104 Horgan Ave, Redwood City
$4,495,000
2170 Bayhill Ct, Half Moon Bay
$2,200,000
898 Lomita Ave, Millbrae
$1,998,000
742 Homer Ave, Palo Alto
$1,100,000
1811 Woodland Ave, East Palo Alto
$1,998,000
3525 Park Blvd, Palo Alto
$3,198,000
841 Ilima Ct, Palo Alto
$3,988,000
1390 Marinovich Way, Los Altos
$5,899,000
39 Pilgrim Rd, Nantucket
$869,000
611 Adeline Ave, San Jose
$2,588,000
758 Holbrook Pl, Sunnyvale
$1,599,000
449 S 16th St, San Jose
$2,298,000
2418 Fairglen Dr, San Jose
$7,750,000
501 El Cerrito Ave, Hillsborough
$998,000
204 N Frances St, Sunnyvale
$1,799,000
1415 Settle Ave, San Jose
$1,888,888
1651 Mount Vernon Dr, San Jose
$949,999
43 Bassett St, San Jose
$2,498,000
591 16th Ave, Menlo Park
$2,888,000
45 El Bonito Way, Millbrae
$2,998,000
2593 Cowper St, Palo Alto
$7,988,000
716 Linden Ave, Los Altos
$1,488,000
213 Velvetlake Dr, Sunnyvale
$3,990,000
20387 Clay St, Cupertino
$1,390,000
822 Sunnyarbor Ct, Campbell
$1,338,000
369 Grandin Ct, San Jose
$1,398,000
594 N Daniel Way, San Jose
$2,888,000
4675 Englewood Dr, San Jose
$2,088,888
1753 Ridgetree Way, San Jose
$1,490,000
2725 Mira Bella Cir, Morgan Hill
$7,995,000
16 Black Fish Ln, Nantucket
$3,395,000
1695 Cherry Grove Dr, San Jose
$1,399,888
5707 Lathrop Dr, San Jose
$1,995,000
N 2nd, San Jose
$1,449,000
E Saint John, San Jose
$1,800,000
Arch, Redwood City
$2,495,000
750 California Way, Redwood City
$1,550,000
, San Jose
$4,095,000
Hester, San Jose
$3,100,000
Davis, Redwood City
$2,250,000
James, Redwood City
$2,498,000
1615 Edgewood Rd, Redwood City
$2,699,950
Sixth, Belmont
$1,899,000
17205 Rosemary Cir, Morgan Hill
$3,999,000
Williams, Mountain View
$2,500,000
Mountain Vw, Mountain View
$5,580,000
Easy, Mountain View
$2,399,000
317-319 Waverly St, Sunnyvale
$2,288,000
1248 Cortez Dr, Sunnyvale
$1,448,800
20276 Pinntage Pkwy, Cupertino
$2,650,000
Pomeroy Ave, Santa Clara
$3,995,000
Halford, Santa Clara
$2,300,000
1664 Whitwood Ln, Campbell
$3,998,000
100 Calfhill Ct, Los Gatos
$2,750,000
S Almaden, San Jose
$1,575,000
N 1st, San Jose
$6,200,000
S 4th, San Jose
$2,099,000
Villa, San Jose
$2,100,000
Deland, San Jose
$1,898,000
Cleveland, San Jose
$1,880,000
David, San Jose
$1,099,000
334 Santana Row Apt 321, San Jose
$1,685,000
482 Stonefield Ct, San Jose
$8,800,000
Latham, Mountain View
$3,900,000
Charles, Sunnyvale
$1,580,000
E Julian, San Jose
$1,399,000
670 S 15th St, San Jose
$3,300,000
Alden, San Jose
$1,499,000
6039 Foothill Glen Dr, San Jose
$1,450,000
2809-2807 Union Ave, San Jose
$1,588,888
Leigh, San Jose
$3,580,000
David, San Jose
$808,000
186 Truckee Ln, San Jose
$2,499,000
625 Glenloch Way, Redwood City
$2,600,000
509 Hillside Rd, Redwood City
$2,998,000
Whipple, Redwood City
$2,388,888
175 Miramonte Ave, Morgan Hill
$3,098,000
Everett, Palo Alto
$4,300,000
Dunster, Campbell
$1,525,000
Nordale, San Jose
$4,150,000
S 5th, San Jose
$2,599,000
N 5th, San Jose
$2,800,000
Alden, San Jose
$1,550,000
S Buena Vis, San Jose
$4,998,000
Tilton, San Mateo
$1,999,000
State, San Mateo
$2,225,000
Bush, San Carlos
$8,900,000
N Bayshore, San Mateo
$4,788,888
Roble, Menlo Park
$2,300,000
549 Prospect St, San Carlos
$2,750,000
N Amphlett, San Mateo
$5,425,000
N Amphlett, San Mateo
$2,698,000
1656 Lachine Dr, Sunnyvale
$1,498,000
720 San Ramon Ct, Morgan Hill
$2,899,000
906 Liberty Ct, Cupertino
$2,998,000
10449 Colby Ave, Cupertino
$1,398,000
3039 Seyferth Way, San Jose
$3,150,000
12 Beach Grass Rd, Nantucket
$1,050,000
728 Commercial Ave, South San Francisco
$1,198,000
1307 Hill Ave, Menlo Park
$2,195,000
3815 Vineyard Dr, Redwood City
$5,750,000
740 Arroyo Rd, Los Altos
$4,988,000
264 Leland Ave, Menlo Park
$5,200,000
643 W Glen Way, Woodside
$7,888,000
685 Riviera Dr, Los Altos
$2,350,000
17408 Blue Jay Dr, Morgan Hill
$2,300,000
704 Borello Way, Mountain View
$1,075,000
1080 S 8th St, San Jose
$3,150,000
319 Marmona Dr, Menlo Park
$3,288,000
1505 Solana Dr, Belmont
$900,000
1137 Yvette Ct, San Jose
$1,488,000
3726 Branson Dr, San Mateo
$1,175,000
1210 Nestwood Way, Milpitas
$2,798,000
151 Louise Ln, San Mateo
$8,950,000
27 Catalpa Dr, Atherton
$2,488,888
2015 Ticonderoga Dr, San Mateo
$3,300,000
751 San Benito Ave, Menlo Park
$1,095,000
23A Daffodil Ln, Nantucket
$998,000
386 Margaret St, San Jose
$2,795,000
2087 Belle Ave, San Carlos
$970,000
2281 Brentwood Ct, East Palo Alto
$1,298,000
44 S 16th St, San Jose
$1,149,950
920 Masson Ave, San Bruno
$999,888
1483 Mercury Ct, Milpitas
$3,995,000
301 College Ave, Palo Alto
$598,000
2786 Mauricia Ave, Santa Clara
$2,399,000
1021 Carola Ave, San Jose
$695,000
37 Sheep Pond Rd, Nantucket
$1,399,000
16761 Dry Creek Ct, Morgan Hill
$2,888,888
1117 Clydebank Ct, Sunnyvale
$3,999,888
14211 Old Wood Rd, Saratoga
$2,788,000
650 Ashton Ave, Palo Alto
$3,950,000
26 Botany Ct, Redwood City
$1,888,000
2057 El Capitan Ave, Santa Clara
$4,488,000
5337 Canyon Hills Ln, San Jose
$1,638,000
837 Dwight Ave, Sunnyvale
$2,198,000
4886 Clarendon Dr, San Jose
$1,648,000
1971 Cordilleras Rd, Redwood City
$4,595,000
881 Vista Dr, Redwood City
$1,198,000
138 Rockwood Dr, South San Francisco
$1,698,888
163 Rodrigues Ave, Milpitas
$1,599,000
150 Tehama Ct, San Bruno
$1,799,000
860 W Edmundson Ave, Morgan Hill
$1,500,000
290 N Rengstorff Ave, Mountain View
$2,188,000
2532 Rose Way, Santa Clara
$2,485,888
2820 Steinhart Ct, Santa Clara
$2,599,888
18857 Montalvo Oaks Cir, Monte Sereno
$1,998,000
1364 Boysea Dr, San Jose
$3,000,000
1598 Willowbrook Dr, San Jose
$1,499,998
1850 Comstock Ln, San Jose
$1,799,000
1533 Santa Inez Dr, San Jose
$1,788,888
1490 Maxine Ave, San Jose
$1,598,000
1660 Lincoln Ave, San Jose
$2,998,000
3928 Caxton Ct, San Jose
$639,000
2555 Gimelli Ct Apt 62, San Jose
$2,250,000
911 Madison Ave, Redwood City
$3,388,000
13158 Stewart Ct, Saratoga
$1,388,000
24 N Idaho St, San Mateo
$3,800,000
115 Durham St, Menlo Park
$2,488,800
1038 Holly St, San Carlos
$2,895,000
1455 Ascension Dr, San Mateo
$2,899,888
3605 Kingridge Dr, San Mateo
$9,950,000
216 Valparaiso Ave, Atherton
$1,825,000
934 S Delaware St, San Mateo
$2,398,000
1505 Union Ave, Redwood City
$2,250,000
155 12th Ave, San Mateo
$2,645,880
691 Sheraton Dr, Sunnyvale
$1,198,000
221 N Delaware St, San Mateo
$2,150,000
396 Port Royal Ave, Foster City
$1,500,000
17845 Elaine Ct, Morgan Hill
$1,698,000
460 Markham Ave, San Bruno
$4,498,888
21600 Walton Ave, San Jose
$2,288,000
126 Danbury Ln, Redwood City
$2,750,000
1480 Chukar Ct, Sunnyvale
$3,690,000
453 Remillard Dr, Hillsborough
$1,880,000
1156 Ayala Dr, Sunnyvale
$1,399,000
3539 Kirk Rd, San Jose
$1,250,000
33 Northcrest Dr, South San Francisco
$1,695,000
65 Cleaves Ave, San Jose
$1,395,000
1617 Greenwood Way, Milpitas
$1,675,000
5921 Indian Ave, San Jose
$2,649,000
343 Maclane St, Palo Alto
$2,555,000
867 Arcturus Cir, Foster City
$925,000
1182 Pomeroy Ave, Santa Clara
$1,199,000
18240 Ransen Ct, Morgan Hill
$1,250,000
1392 Turlock Ln, San Jose
$1,748,000
1666 Creek Dr, San Jose
$1,599,888
1901 Camden Ave, San Jose
$1,718,000
5836 Terrazzo Ct, San Jose
$2,198,000
2282 Fairglen Dr, San Jose
$1,785,000
1054 Timbercrest Dr, San Jose
$2,485,000
7182 Silver Lode Ln, San Jose
$1,188,000
711 Emerson Ct, San Jose
$6,400,000
4915 Formby Ct, San Jose
$1,199,000
91 Southbrook Dr, San Jose
$3,998,000
1071 Carolyn Ave, San Jose
$1,848,000
2114 Villanova Rd, San Jose
$2,199,950
1600 Ark St, San Mateo
$1,495,000
346 Del Monte Ave, South San Francisco
$1,325,000
1148 LA Rochelle Ter Unit C, Sunnyvale
$1,398,000
588 Borregas Ave, Sunnyvale
$1,395,000
27 Havenridge Ct, San Mateo
$2,500,000
539 Silver Ave, Half Moon Bay
$2,780,000
300 Helen Dr, Millbrae
$1,825,000
686 Reseda Dr, Sunnyvale
$1,995,000
1624 Sunnyslope Ave, Belmont
$2,198,000
23 Michael Ln, Millbrae
$1,688,000
101 Butterweed Ln, Brisbane
$2,795,000
1476 Forge Rd, San Mateo
$1,789,000
421 W 39th Ave, San Mateo
$1,749,000
780 San Pedro Ave, Morgan Hill
$2,399,000
4178 Alta Mesa Ave, Palo Alto
$6,488,000
740 Spencer Ct, Los Altos
$1,588,800
923 Delano Ter Unit 1, Sunnyvale
$2,248,000
883 Roble Dr, Sunnyvale
$3,488,000
884 Hanover Ave, Sunnyvale
$2,798,000
821 Cumberland Dr, Sunnyvale
$2,650,000
10770 Martinwood Way, Cupertino
$1,275,000
1106 Monroe St, Santa Clara
$3,999,888
20301 Kirkmont Dr, Saratoga
$1,349,000
1011 S 9th St, San Jose
$1,598,000
14 and 16 Garden Ln, San Mateo
$4,995,000
2160 Cedar Ave, Menlo Park
$925,000
629 Millich Dr, Campbell
$2,099,000
5540 Dartmouth Dr, San Jose
$3,395,000
17A Daffodil Ln Unit A, Nantucket
$2,549,000
5916 Pistoia Way, San Jose
$1,588,000
999 Lurline Dr, Foster City
$1,398,000
1164 Morrill Ave, San Jose
$2,050,000
1273 Cortez Dr, Sunnyvale
$1,198,000
5764 Halleck Dr, San Jose
$1,725,000
106 George Ct, Campbell
$2,548,000
2620 Monserat Ave, Belmont
$3,998,000
142 Johnson Ave, Los Gatos
$4,000,000
1037 Harker Ave, Palo Alto
$2,588,888
1464 Georgetta Dr, San Jose
$2,398,000
1567 Oak Point Ter, Sunnyvale
$525,000
1885 E Bayshore Rd Spc 7, East Palo Alto
$1,699,888
1555 Westmont Ave, Campbell
$1,398,000
1419 Kooser Rd, San Jose
$915,000
4744 Durango River Ct, San Jose
$1,285,000
2754 Georgetown St, East Palo Alto
$3,899,000
134 Donohoe St, East Palo Alto
$3,178,000
12457 Lolly Ct, Saratoga
$999,000
1596 Camden Village Cir, San Jose
$2,315,000
1276 Avis Dr, San Jose
$1,299,000
3072 Mary Helen Ln, San Jose
$3,098,000
14785 Nelson Way, San Jose
$1,725,000
926 Larkspur Dr, Millbrae
$1,999,999
415 S 14th St, San Jose
$428,888
5717 Makati Cir Apt G, San Jose
$2,788,000
1245 Laurel Hill Dr, San Mateo
$1,650,000
1833 Redwood Ave, Redwood City
$3,980,000
488 Gilbert Ave, Menlo Park
$1,799,950
967 Elizabeth Dr, Santa Clara
$758,888
596 Walnut St, San Bruno
$1,598,000
2820 Evergreen Dr, San Bruno
$1,450,000
253 Spring Valley Ln, Milpitas
$3,698,000
716 Gailen Ave, Palo Alto
$2,388,000
1608 Longspur Ave, Sunnyvale
$520,000
1534 Alma Ter, San Jose
$2,688,000
20362 Via Napoli, Cupertino
$1,899,950
2005 Stanley Ave, Santa Clara
$1,295,000
6076 Ashburton Dr, San Jose
$3,195,000
24 Macys Ln, Nantucket
$1,695,000
6 Little Isle Ln, Nantucket
$1,799,000
2182 Bowers Ave, Santa Clara
$2,798,000
1041 Crestview Dr, Millbrae
$5,800,000
11008 Sycamore Dr, Cupertino
$2,598,000
1012 Riverside Dr, San Jose
$1,499,000
1357 Goldenlake Rd, San Jose
$2,699,000
512 Bryan Ave, Sunnyvale
$2,800,000
108 Mojonera Ct, Los Gatos
$3,990,000
207 Hawthorne Ave, Palo Alto
$5,299,000
17625 Bruce Ave, Los Gatos
$1,990,000
395 S 13th St, San Jose
$1,849,950
2175 Laurelei Ave, San Jose
$5,980,000
17085 17087 Summit Way, Los Gatos
$1,699,000
2583 Benton St, Santa Clara
$1,450,000
358 S Cypress Ave, San Jose
$1,650,000
750 Almeria Dr, San Jose
$899,900
2531 Illinois St, East Palo Alto
$2,298,000
2464 Betlo Ave, Mountain View
$1,500,000
216 Bartlett Ave, Sunnyvale
$3,998,000
14180 Perata Ct, Saratoga
$1,498,000
1858 Comstock Ln, San Jose
$2,700,000
165 Piedra Dr, Sunnyvale
$2,350,000
930 Wainwright Dr, San Jose
$2,798,000
4122 Woodford Dr, San Jose
$1,999,999
5008 Leigh Ave, San Jose
$2,200,000
542 Grand Ave, South San Francisco
$1,350,000
1582 Starlite Dr, Milpitas
$3,488,000
2751 Richland Ave, San Jose
$2,098,000
1003 Bluebonnet Dr, Sunnyvale
$1,499,888
708 Ardis Ave, San Jose
$2,450,000
3973 Twilight Dr, San Jose
$1,249,000
215 Newbridge St, Menlo Park
$1,499,000
5940 Jenny Lind Ct, San Jose
$4,250,000
1090 Rose Orchard Pl, Morgan Hill
$3,950,000
1095 Rose Orchard Pl, Morgan Hill
$6,688,000
57 E 1st St, Morgan Hill
$6,688,000
70 E Main Ave, Morgan Hill
$1,099,999
1643 Stardust Ct, Santa Clara
$3,648,000
15580 Loma Vista Ave, Los Gatos
$1,250,283
1206 Diego Ln, Morgan Hill
$1,360,207
1230 Francisco Ln, Morgan Hill
$1,299,000
2576 Forest Ave, San Jose
$1,999,888
5222 War Wagon Dr, San Jose
$1,699,999
5860 McGilvra Ct, San Jose
$4,488,000
434 Fernando Ave, Palo Alto
$3,615,000
17215 Copper Hill Dr, Morgan Hill
$1,899,950
5524 Harvard Dr, San Jose
$3,588,000
1741 Nomark Ct, San Jose
$6,688,000
55 E 1st St, Morgan Hill
$1,340,840
18062 Calabazas Ln, Morgan Hill
$1,950,000
17240 Copper Hill Dr, Morgan Hill
$2,950,888
17400 Serene Dr, Morgan Hill
$1,349,000
17200 Copper Hill Dr, Morgan Hill
$1,650,000
17555 Manzanita Dr, Morgan Hill
$1,099,999
17076 Shady Lane Dr, Morgan Hill
$1,549,000
640 Easy St, Morgan Hill
$1,449,999
17285 Copper Hill Dr, Morgan Hill
$1,950,000
17520 Serene Dr, Morgan Hill
$1,399,988
17815 Woodland Ave, Morgan Hill
$2,298,000
15298 Sycamore Dr, Morgan Hill
$799,000
18041 Hillwood Ln, Morgan Hill
$1,799,888
17864 Holiday Dr, Morgan Hill
$1,290,000
16195 Church St, Morgan Hill
$1,499,900
384 Via Loma, Morgan Hill
$1,250,000
570 Biscayne Ct, Morgan Hill
$650,000
744 Anne Ln, Morgan Hill
$656,000
195 Del Monte Ln, Morgan Hill
$1,325,000
19185 Saffron Dr, Morgan Hill
$1,389,000
5224 Twin Falls Rd, Morgan Hill
$599,000
4400 Casa Loma Rd, Morgan Hill
$2,895,000
18600 Castle Ridge Dr, Morgan Hill
$1,199,900
23 Tilton Ave, Morgan Hill
$1,153,000
17109 Shady Lane Dr, Morgan Hill
$665,000
131 LA Crosse Dr, Morgan Hill
$994,888
176 E Main Ave, Morgan Hill
$4,200,000
19963 Hale Ave, Morgan Hill
$650,000
16715 Rita Dr, Morgan Hill
$1,699,000
2729 Mira Bella Cir, Morgan Hill
$1,349,000
726 San Cristoval Ct, Morgan Hill
$644,950
16725 Rita Dr, Morgan Hill
$899,000
190 Warren Ave, Morgan Hill
$1,895,000
17395 Pineau Ct, Morgan Hill
$1,499,999
15565 Armsby Ln, Morgan Hill
$2,180,000
844 Black Walnut Way, Morgan Hill
$1,499,000
475 Calle Asta, Morgan Hill
$3,595,000
18600 Corte Arcangel, Morgan Hill
$1,999,888
13925 Sheila Ave, Morgan Hill
$1,239,000
830 Dakota Dr, Morgan Hill
$2,149,000
13175 Chaparral Rd, Morgan Hill
$3,849,990
18471 Corte Zapala, Morgan Hill
$1,350,000
16610 San Benito Pl, Morgan Hill
$1,569,000
16935 Pine Way, Morgan Hill
$2,600,000
, Morgan Hill
$1,990,000
2745 Cantor Dr, Morgan Hill
$1,265,588
18054 Calabazas Ln, Morgan Hill
$1,099,000
17495 Blue Jay Dr, Morgan Hill
$798,000
17079 Creekside Cir, Morgan Hill
$1,390,000
1080 Easy St, Morgan Hill
$1,448,000
17387 Walnut Grove Dr, Morgan Hill
$1,499,999
17488 Holiday Dr, Morgan Hill
$1,333,000
14960 Dark Star Ct, Morgan Hill
$1,298,800
17054 Mimosa Dr, Morgan Hill
$2,749,500
18713 White Moon Dr, Morgan Hill
$900,000
7150 Croy Rd Unit A, Morgan Hill
$1,590,000
17710 Holiday Dr, Morgan Hill
$1,799,999
16845 Zinfandel Cir, Morgan Hill
$3,500,000
14545 Atherton Cir, Morgan Hill
$1,988,000
15640 Foothill Ave, Morgan Hill
$2,950,000
18430 Corte Anacapi, Morgan Hill
The screener ranks what is already listed. The same underbuilt signals also power the target lists behind unlisted deals: our guide to finding off-market teardown opportunities on the SF Peninsula covers owner outreach, probate and pre-foreclosure records, and the listing-lifecycle triggers that surface these lots before they reach the MLS. This is the same daily-refreshed data platform behind AddressIntel’s ADU and SB 9 screeners, a monthly Developer Market Opportunities Report, and a REST API.
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Underbuilt-Lot Screener FAQ
What is an "underbuilt" lot?
A lot is underbuilt when the existing house uses only a small share of the floor area the zoning would allow, for example, a 1,200 sqft mid-century home on a lot where the city permits 3,500+ sqft. The unused building envelope is the opportunity: add square footage, or scrape and rebuild larger.
How is the redevelopment score calculated?
We estimate the maximum single-family gross floor area allowed on each lot using the city's own zoning rule (its floor-area-ratio formula or coverage/height limits), then compare it to the existing living area to get a utilization percentage and the buildable headroom in square feet. The 0-100 score weights how far below the envelope the home is, its age, and lot size. It is a screening estimate, verify FAR, setbacks, and height with the local planning department.
What is the difference between "expansion room" and a "teardown candidate"?
Expansion room means there is meaningful unused floor area to add on. A teardown candidate is flagged only when a home is both using a low share of its envelope AND is older (pre-1978) on a sizable lot, the profile where a scrape-and-rebuild typically pencils out. Requiring both age and low utilization keeps newer small homes from being mislabeled.
Where do the floor-area limits come from?
Each city sets its own single-family FAR or floor-area limit in its zoning code. We curate the actual rule per city, including sliding-scale formulas (Palo Alto, Mountain View, Menlo Park, Los Altos, Saratoga, Los Gatos), with a municipal-code citation and an as-of date. Cities we have not individually curated, or that set no explicit FAR, use a clearly-flagged conservative estimate.
Does this pair with SB 9 and ADU analysis?
Yes. An underbuilt lot that is also SB 9-eligible or strong for an ADU is a compounding opportunity: you can expand the primary home, split the lot, or add units. The property detail page shows all three signals side by side.
Which markets does the screener cover?
Active listings across San Mateo County and Santa Clara County, scored against each jurisdiction's floor-area rules so you can focus on the most underbuilt Silicon Valley lots.
Is this underbuilt-lot screener part of a larger platform?
Yes. It is one screener inside AddressIntel, a real estate data platform built for Silicon Valley developers, spec builders, and investors. The same permit and parcel data also powers our SB 9 lot-split and ADU-feasibility screeners and the teardown ROI model, so a listing’s teardown, SB 9, and ADU signals all live together on its detail page. Beyond active listings, AddressIntel also surfaces off-market teardown candidates through a monthly Developer Market Opportunities Report and a REST API.
See every signal on one lot
AddressIntel scores every Silicon Valley listing for teardown, SB 9, and ADU upside side by side, plus off-market candidates that never make it to MLS.
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