BuildingCensus

Biggest building emitters in Seattle

Top 100 by reported greenhouse-gas emissions under Seattle Energy Benchmarking Ordinance (SMC 22.920), latest disclosure year per building. Seattle's Building Emissions Performance Standard (adopted 2023) applies to buildings over 20,000 sq ft: benchmarking verification is due 2027–2030 and initial emissions targets 2031–2035, reaching net zero by 2041–2050, with fines for non-compliance.

At a glance

Uw - University Of Washington Seattle Campus (Master) is Seattle's biggest reported building emitter, at 113,771 tCO₂e in its 2025 disclosure. The 100 buildings ranked here reported 258,134 tCO₂e together — 54% of the 478,698 tCO₂e disclosed by all 3,871 Seattle buildings.

Top 100 by reported emissions

#BuildingCityEmissionsScoreFloor area
1Uw - University Of Washington Seattle Campus (Master)Seattle113,771 tCO₂e–—15,216,474 sq ft
2Harborview Medical Center - CampusSeattle9,934 tCO₂eA971,926,841 sq ft
3University Of Washington Medical Center (Uwmc)Seattle9,652 tCO₂eB831,739,802 sq ft
4Swedish Medical Center First Hill - CampusSeattle9,147 tCO₂e–—2,080,885 sq ft
5Seattle Children's Hospital (Main Campus)Seattle6,604 tCO₂eC56879,000 sq ft
6Boeing Plant 2 - CampusSeattle5,227 tCO₂e–—2,026,324 sq ft
7Swedish Medical Center Cherry Hill - CampusSeattle4,279 tCO₂eB73597,519 sq ft
8Virginia Mason - Central PavilionSeattle3,766 tCO₂eB81374,466 sq ft
9Seattle University (Main Campus)Seattle3,213 tCO₂e–—2,099,379 sq ft
10Westin Hotel (Parent Building)Seattle2,881 tCO₂eC63956,110 sq ft
11Fhcrc - Weintraub/Hutchinson/Thomas Bldgs CombinedSeattle2,634 tCO₂e–—603,009 sq ft
12Four Seasons Hotel & 99 Union Street Private ResidencesSeattle2,415 tCO₂e–—455,883 sq ft
13Research & Training Building (Harborview) -Seattle2,321 tCO₂e–—181,930 sq ft
14Sheraton Grand Seattle - (Parent Building)Seattle2,298 tCO₂eB781,083,197 sq ft
15Seattle Convention CenterSeattle2,225 tCO₂e–—1,842,925 sq ft
16Swedish Medical Center Ballard - CampusSeattle2,050 tCO₂eD38451,526 sq ft
17Seattle Central Community College Master Campus Id (Benchmarking)Seattle1,903 tCO₂e–—122,976 sq ft
18T-Mobile Park (Safeco Field)Seattle1,840 tCO₂e–—1,172,127 sq ft
19Fairmont Olympic HotelSeattle1,815 tCO₂eB71544,174 sq ft
20Seattle Children's Building CureSeattle1,802 tCO₂e–—575,826 sq ft
21Providence Mt St VincentSeattle1,777 tCO₂eD44371,257 sq ft
22Virginia Mason - Jones PavilionSeattle1,721 tCO₂eD52267,470 sq ft
23King County CourthouseSeattle1,712 tCO₂eC56540,360 sq ft
24UW Medicine Phase 3Seattle1,689 tCO₂e–—339,591 sq ft
25Seattle Children's Hospital (Jack R Mcdonald Building)Seattle1,683 tCO₂e–—299,070 sq ft
26King County Correctional FacilitySeattle1,586 tCO₂e–—385,274 sq ft
27The Westin Building Exchange (Office)Seattle1,498 tCO₂e–—429,405 sq ft
28Onni South Lake UnionSeattle1,470 tCO₂eB771,546,084 sq ft
29Washington Athletic ClubSeattle1,438 tCO₂e–—305,548 sq ft
30Seattle Art MuseumSeattle1,277 tCO₂e–—280,230 sq ft
31Horizon HouseSeattle1,191 tCO₂eA92756,740 sq ft
32The Juno BuildingSeattle1,183 tCO₂e–—443,118 sq ft
33Sodo Urban WorksSeattle1,126 tCO₂e–—188,681 sq ft
341208 Eastlake Ave E (Dendreon)Seattle1,108 tCO₂e–—128,408 sq ft
35Mirabella Retirement CommunitySeattle1,063 tCO₂eA97724,148 sq ft
36Olive 8 (Mixed Use)Seattle1,062 tCO₂eC64675,497 sq ft
37Kraken Community Iceplex - Northgate Station Lot 6Seattle1,032 tCO₂e–—172,297 sq ft
38Puget Sound PlazaSeattle1,022 tCO₂eC66552,176 sq ft
39Seattle Cancer Care Alliance ClinicSeattle988 tCO₂e–—351,530 sq ft
40ARNOLD PAVILLIONSeattle980 tCO₂e–—225,982 sq ft
41Centurylink Field-StadiumSeattle974 tCO₂e–—1,913,640 sq ft
42First Hill Medical Pavilion (Hart First Hill Llc)Seattle961 tCO₂e–—383,914 sq ft
43UW MEDICINE-LK UNION PHASE II ITHS.ORGSeattle954 tCO₂e–—436,497 sq ft
442200 WestlakeSeattle924 tCO₂eA96516,407 sq ft
45Seattle Children's Hospital Building HopeSeattle903 tCO₂eA98330,000 sq ft
46Grand Hyatt SeattleSeattle895 tCO₂e–—838,117 sq ft
47188 East BlaineSeattle877 tCO₂e–—310,584 sq ft
48ParkshoreSeattle864 tCO₂eD23225,629 sq ft
49401 Terry Ave (Institute For System Biology)Seattle841 tCO₂e–—258,505 sq ft
501616 Eastlake BuildingSeattle827 tCO₂e–—281,306 sq ft
51Expedia - CampusSeattle826 tCO₂eA861,552,140 sq ft
52Edgewater InnSeattle823 tCO₂eD37122,309 sq ft
53Komo Plaza East & West BuildingsSeattle815 tCO₂e–—524,610 sq ft
54PLAZA 600 BUILDINGSeattle815 tCO₂eB81265,851 sq ft
55Day 1 Tower And Spheres (Amazon)Seattle814 tCO₂eA931,599,230 sq ft
56Bill & Melinda Gates FoundationSeattle813 tCO₂eB73920,598 sq ft
57Harbor Steps Ne SiteSeattle804 tCO₂eB811,256,335 sq ft
58Skye At BelltownSeattle783 tCO₂eB76393,841 sq ft
59Allen Institute For Brain Science (Aibs)Seattle769 tCO₂e–—345,290 sq ft
60Port Of Seattle- Terminal 91 (Campus)Seattle762 tCO₂e–—1,012,278 sq ft
61Port Of Seattle Bell Harbor Complex & Conference - CampusSeattle744 tCO₂e–—217,088 sq ft
62Concord CondominiumSeattle728 tCO₂eD11219,874 sq ft
63Jefferson TowerSeattle718 tCO₂eB76108,618 sq ft
641201 Eastlake Ave E (Zymogenetics)Seattle717 tCO₂e–—169,785 sq ft
65Ups WarehouseSeattle709 tCO₂e–—141,686 sq ft
66Seattle Tennis ClubSeattle703 tCO₂e–—71,280 sq ft
67Caroline Kline Galland HomeSeattle697 tCO₂eA93141,297 sq ft
68Seattle Waterfront MarriottSeattle687 tCO₂eD49293,030 sq ft
69Brotman Building D: UW Medicine ResearchSeattle676 tCO₂e–—102,235 sq ft
70Embassy Suites- Downtown SeattleSeattle672 tCO₂eA91680,770 sq ft
71THORNTON PLACE APTS BLD 2 (CHILD PROPERTY FOR #52046)Seattle666 tCO₂eC60124,642 sq ft
72University Village South BldgSeattle660 tCO₂e–—305,025 sq ft
73Stratus Apartments- Mixed UseSeattle648 tCO₂eC69614,765 sq ft
74Rainier Square Tower (Mf + Commercial)Seattle641 tCO₂eB741,527,817 sq ft
75Seattle TowerSeattle635 tCO₂e–—216,571 sq ft
76Costco 4th Ave SSeattle633 tCO₂eC65158,415 sq ft
77Fifteen Twenty-One Second AvenueSeattle628 tCO₂eD31330,693 sq ft
78The SummitSeattle625 tCO₂eD21207,022 sq ft
79Renaissance Madison HotelSeattle623 tCO₂eC63460,902 sq ft
80Pier 57 Bay PavilionSeattle615 tCO₂e–—43,728 sq ft
81Amazon Doppler BuildingSeattle603 tCO₂eA901,496,961 sq ft
82Frye Art MuseumSeattle602 tCO₂e–—47,699 sq ft
83Centurylink: Seattle Bell PlazaSeattle596 tCO₂eA91791,396 sq ft
84Wash Mutual Tower (1201 Third Ave)Seattle593 tCO₂eA921,413,575 sq ft
85JosephinumSeattle580 tCO₂eC69148,219 sq ft
86Data Center, 2020 5TH AVESeattle580 tCO₂e–—82,149 sq ft
87Boeing South Park Campus ReportSeattle578 tCO₂e–—334,368 sq ft
88Fhcrc - Arnold BldgSeattle575 tCO₂eC69560,516 sq ft
89South Seattle College - Campus Master IdSeattle571 tCO₂e–—529,343 sq ft
90Tower 12, 2015 2ND AVESeattle570 tCO₂eB71539,039 sq ft
91Hotel 1000Seattle565 tCO₂eC63392,552 sq ft
92Insignia CondosSeattle553 tCO₂eD471,464,631 sq ft
93F5 TowerSeattle552 tCO₂eB82905,655 sq ft
94Helios AptsSeattle549 tCO₂eB72559,958 sq ft
95Magnuson Park CampusSeattle547 tCO₂e–—564,258 sq ft
96Gilead Sciences Bldg. (Alexandria R.e.) Econ. UniSeattle539 tCO₂e–—175,918 sq ft
97W Seattle HotelSeattle535 tCO₂eB74333,176 sq ft
98THORNTON CINEMA BUILDING & PARKING GARAGE (CHILD PROPERTY FOR #52046)Seattle533 tCO₂e–—423,569 sq ft
99Thornton Place (Parent Property)Seattle532 tCO₂eC61771,253 sq ft
100Continental Place CondominiumSeattle529 tCO₂eD30190,610 sq ft

What do Seattle's biggest-emitting buildings have in common?

By property type the list is led by mixed use property (15), laboratory (14) and multifamily housing (13). Their average site EUI is 146.0 kBtu/ft², about 207% above the citywide average of 47.6 kBtu/ft². Combined they cover 75.3 million square feet; the median ranked building has 429,405 sq ft.

The ranking orders Seattle's disclosed buildings by total reported greenhouse-gas emissions in their latest report year; figures far outside what a building of that type and size can emit are treated as data-entry errors and left out.

More Seattle rankings and data

Frequently asked questions

Which Seattle building emits the most carbon?

Uw - University Of Washington Seattle Campus (Master) reported 113,771 tCO₂e in its latest Seattle Energy Benchmarking Ordinance (SMC 22.920) disclosure — the highest in Seattle. Seattle's Building Emissions Performance Standard (adopted 2023) applies to buildings over 20,000 sq ft: benchmarking verification is due 2027–2030 and initial emissions targets 2031–2035, reaching net zero by 2041–2050, with fines for non-compliance.

About this data

Source: Building Energy Benchmarking (Seattle Energy Benchmarking Ordinance (SMC 22.920)), as published October 2, 2026. See the methodology for how records are matched, cleaned and scored.

Cite as: BuildingCensus, “Biggest-emitting buildings in Seattle”, https://buildingcensus.com/rankings/biggest-emitters/seattle (data as of October 2, 2026).