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Engineer License 90242

Trylon Tsf

The city has issued 9 of the 13 San Francisco building permits that name Trylon Tsf since 2018. The work is a mix of residential and commercial, led by apartments and multifamily. Their median plan-review permit for apartments and multifamily took 5.6 months from filing to issue, 11% faster than the citywide median. Their busiest neighborhoods are Financial District/South Beach, Bayview Hunters Point and South of Market.

Issued by the city
9 of 13 filed since 2018
Median plan-review time, apartments and multifamily
5.6 mo city median 6.2 mo
Rank for apartments and multifamily
No. 195 of 516 by apartments and multifamily issued
Overall rank
No. 417 of 1,146 engineers

What they work on

Every San Francisco building permit with Trylon Tsf on the record since 2018, by project type. Most filed: 8 apartments and multifamily, 3 offices, 1 restaurants and bars.

Residential and commercial, by permits filed

62% residential
39% commercial
Permits by project type, filed and issued
  1. Apartments and multifamily Residential 7 of 8 issued 62% of filings.
  2. Offices Commercial 1 of 3 issued 23% of filings.
  3. Restaurants and bars Commercial 1 of 1 issued 8% of filings.
  4. Hotels, clinics, schools and other commercial Commercial 0 of 1 issued 8% of filings.

Permits over time

Permits filed each year, drawn as a street with one building per year, and how many of all their permits the city has issued.

Busiest year
2020
12 permits filed
Latest filing
May 2022
69% of 13 issued
Permits filed per year: 2018: 0, 2019: 0, 2020: 12, 2021: 0, 2022: 1, 2023: 0, 2024: 0, 2025: 0, 2026: 0. The 2026 figure runs through October 20, 2026.

One building per year, its height the permits filed. Each floor line marks 2 permits; the 2026 building is dashed because it counts permits filed through October 20, 2026.

Issued by the city: 9 of 13 permits filed

69%

All San Francisco project permits since 2018 in this data

93% issued

4 not issued as of October 20, 2026. Source: SF Department of Building Inspection permits via DataSF.

How fast their permits come through

Filing to issue for permits that went through plan review. Trylon Tsf has 12 of those across all project types; the citywide comparison is for apartments and multifamily, their most filed type, where 3,633 of 59,927 permits went through plan review and the rest were approved over the counter.

Trylon Tsf, apartments and multifamily

5.6months

That is 11% faster than the citywide median for apartments and multifamily.

Median months from filing to issue for plan-review permits. Trylon Tsf, apartments and multifamily: 5.6 months. San Francisco, apartments and multifamily: 6.2 months. Middle half of city permits: 2.7 to 12.3 months.
5.6 months for apartments and multifamily, faster than 78 of 106 other engineers ranked for apartments and multifamily that have a median for it Each circle is a firm's median for its plan-review permits for apartments and multifamily. Dashed line: the median of all San Francisco plan-review permits for apartments and multifamily, 6.2 months. Shaded: the middle half of those permits, 2.7 to 12.3 months.
0 3 6 9 12 15 18 21+ months Unicorn Consulting: 9.0 months Ecr Engineering: 4.1 months Double D Engineering: 10.8 months Altos Engineering: 4.4 months Atrium Structural Engineer: 12.8 months Rs Engineering: 17.9 months Enertia Designs: 13.9 months Lawrence Liao Str. Eng: 8.5 months Mercury Engineering Group: 9.4 months Ice Design Inc.: 17.9 months Kevin O'connor Inc.: 5.2 months Innovative Const: 20.2 months Design Consultants Group, Inc: 9.4 months Sia Consulting Corp: 17.7 months Mhc Engineers: 5.0 months Murphy Burr Curry Inc.: 6.9 months Hom & Pisano Engineering Inc.: 8.3 months Base Design: 13.1 months One Design: 17.3 months Erwin O'toole: 4.8 months Rei Build Up Design: 11.9 months W. Charles Perry & Assoc.: 20.1 months Yuflux Engineering Llc.: 8.1 months Acies Engineering: 3.4 months Kung Kay Chiu: 1.2 months Zfa Structural Engineers: 8.5 months Hcg Associates, Inc.: 13.3 months Telesis: 6.1 months Doug Lee: 22.9 months Q Architecture: 12.2 months Streamline Engineering: 5.3 months Nabi Const. & Engineering: 3.4 months Bkf Engineers: 13.5 months Smith Engineering, Inc.: 9.4 months Ftf Engineering Inc.: 4.6 months Degenkolb Engineers: 7.6 months Acg Engineers Inc: 6.8 months Kpff: 10.1 months Ny Engineering Consulting: 14.8 months Simpson Gumpertz & Heger: 13.2 months Dci Engineers: 3.5 months Semco Engineering Inc.: 9.7 months Ashley & Vance Engineering: 9.2 months Edesignc Incorporated: 7.5 months Sergio Mayorga Assc: 31.8 months Mk Engineers Inc.: 12.7 months Engineering 350: 5.8 months A & J Design Associates Inc.: 9.2 months Interlocity: 5.6 months Dolmen Structural Engineer: 5.5 months Smw Associates: 26.1 months Access System & Solutions Inc: 7.8 months Bahman Ghassenmzadeh: 11.4 months Dominguez Associates: 13.3 months Wmstructural: 6.7 months Holmes Culley: 6.1 months Aj Miller And Associates: 2.8 months Interface Engineering: 3.3 months Emerald City: 5.9 months Thomas Podesta Engineer: 30.9 months Hohbach-Lewin, Inc: 13.1 months Soha Engineers: 9.8 months Optimal Design Group: 18.5 months Imeg: 6.5 months Spi Consulting Engineers, Inc.: 11.2 months Julia Y. Chen Design Inc.: 2.2 months Luk And Associates: 6.3 months Integrand Structural Engineer: 13.4 months Duquette Engineering: 8.5 months Kpff Consulting Engineers: 4.5 months S & P Structural Engineers: 33.0 months Framework Engineering: 11.9 months Lx Engineering: 6.8 months Pae: 8.8 months Powell And Associates: 16.6 months Tipping-Mar Structural Eng: 6.5 months Geissler Engineering: 46.9 months D H Charles: 2.2 months Urban Design Consulting Eng: 6.5 months Tommy Siu & Associates: 7.7 months Hc Structural Engineering Inc: 4.3 months Tuan & Robinson Str. Engineer: 8.4 months Gregory Miller Structural Eng.: 8.4 months Drill Tech: 2.8 months Meyers+Engineers: 5.2 months Bay City Mechanical Inc.: 10.4 months Jaime Neilson, P.E., S.E: 4.5 months Edward C. Robinson, Pe: 4.9 months Brierley Associates: 2.7 months Mcginnis & Assoc Consulting: 8.2 months O'brien Mechanical Inc Ii: 6.5 months W.H.Yang Structural Engr: 30.1 months Ficcadenti Waggonen & Castle: 2.8 months Nishkian Menninger: 2.2 months J.W. Mcclenahan Co.: 19.9 months Nexius Solutions Inc: 10.3 months Tuan & Robinson Structural: 4.3 months Condon - Johnson & Assoc.: 8.7 months Calvin Abshier: 14.1 months Craig M. Horner: 17.0 months Desmond Blake: 0.9 months Earthbound: 8.9 months Rde Structural Engineering: 5.6 months Zeiger Engineers Inc.: 13.8 months Wm Tucker Associates: 3.0 months Gary L Hennings: 13.9 months Trylon Tsf 0 3 6 9 12 15 18 21+ months Unicorn Consulting: 9.0 months Ecr Engineering: 4.1 months Double D Engineering: 10.8 months Altos Engineering: 4.4 months Atrium Structural Engineer: 12.8 months Rs Engineering: 17.9 months Enertia Designs: 13.9 months Lawrence Liao Str. Eng: 8.5 months Mercury Engineering Group: 9.4 months Ice Design Inc.: 17.9 months Kevin O'connor Inc.: 5.2 months Innovative Const: 20.2 months Design Consultants Group, Inc: 9.4 months Sia Consulting Corp: 17.7 months Mhc Engineers: 5.0 months Murphy Burr Curry Inc.: 6.9 months Hom & Pisano Engineering Inc.: 8.3 months Base Design: 13.1 months One Design: 17.3 months Erwin O'toole: 4.8 months Rei Build Up Design: 11.9 months W. Charles Perry & Assoc.: 20.1 months Yuflux Engineering Llc.: 8.1 months Acies Engineering: 3.4 months Kung Kay Chiu: 1.2 months Zfa Structural Engineers: 8.5 months Hcg Associates, Inc.: 13.3 months Telesis: 6.1 months Doug Lee: 22.9 months Q Architecture: 12.2 months Streamline Engineering: 5.3 months Nabi Const. & Engineering: 3.4 months Bkf Engineers: 13.5 months Smith Engineering, Inc.: 9.4 months Ftf Engineering Inc.: 4.6 months Degenkolb Engineers: 7.6 months Acg Engineers Inc: 6.8 months Kpff: 10.1 months Ny Engineering Consulting: 14.8 months Simpson Gumpertz & Heger: 13.2 months Dci Engineers: 3.5 months Semco Engineering Inc.: 9.7 months Ashley & Vance Engineering: 9.2 months Edesignc Incorporated: 7.5 months Sergio Mayorga Assc: 31.8 months Mk Engineers Inc.: 12.7 months Engineering 350: 5.8 months A & J Design Associates Inc.: 9.2 months Interlocity: 5.6 months Dolmen Structural Engineer: 5.5 months Smw Associates: 26.1 months Access System & Solutions Inc: 7.8 months Bahman Ghassenmzadeh: 11.4 months Dominguez Associates: 13.3 months Wmstructural: 6.7 months Holmes Culley: 6.1 months Aj Miller And Associates: 2.8 months Interface Engineering: 3.3 months Emerald City: 5.9 months Thomas Podesta Engineer: 30.9 months Hohbach-Lewin, Inc: 13.1 months Soha Engineers: 9.8 months Optimal Design Group: 18.5 months Imeg: 6.5 months Spi Consulting Engineers, Inc.: 11.2 months Julia Y. Chen Design Inc.: 2.2 months Luk And Associates: 6.3 months Integrand Structural Engineer: 13.4 months Duquette Engineering: 8.5 months Kpff Consulting Engineers: 4.5 months S & P Structural Engineers: 33.0 months Framework Engineering: 11.9 months Lx Engineering: 6.8 months Pae: 8.8 months Powell And Associates: 16.6 months Tipping-Mar Structural Eng: 6.5 months Geissler Engineering: 46.9 months D H Charles: 2.2 months Urban Design Consulting Eng: 6.5 months Tommy Siu & Associates: 7.7 months Hc Structural Engineering Inc: 4.3 months Tuan & Robinson Str. Engineer: 8.4 months Gregory Miller Structural Eng.: 8.4 months Drill Tech: 2.8 months Meyers+Engineers: 5.2 months Bay City Mechanical Inc.: 10.4 months Jaime Neilson, P.E., S.E: 4.5 months Edward C. Robinson, Pe: 4.9 months Brierley Associates: 2.7 months Mcginnis & Assoc Consulting: 8.2 months O'brien Mechanical Inc Ii: 6.5 months W.H.Yang Structural Engr: 30.1 months Ficcadenti Waggonen & Castle: 2.8 months Nishkian Menninger: 2.2 months J.W. Mcclenahan Co.: 19.9 months Nexius Solutions Inc: 10.3 months Tuan & Robinson Structural: 4.3 months Condon - Johnson & Assoc.: 8.7 months Calvin Abshier: 14.1 months Craig M. Horner: 17.0 months Desmond Blake: 0.9 months Earthbound: 8.9 months Rde Structural Engineering: 5.6 months Zeiger Engineers Inc.: 13.8 months Wm Tucker Associates: 3.0 months Gary L Hennings: 13.9 months Trylon Tsf

7 firms with medians over 21 months are drawn at the right edge.

Where they rank

Ranked by permits the city has issued since 2018, first across every project type, then for apartments and multifamily alone.

  1. 415 Prostruct Engineering 9
  2. 416 Sierra Engineering Group 9
  3. 417 Trylon Tsf 9
  4. 418 Divis Consulting Inc. 9
  5. 419 Qi Structural Engineering 9

All permits issued, 1,146 engineers Full ranking

  1. 193 Lok C Kwan 7
  2. 194 Lefler Engineering, Inc 7
  3. 195 Trylon Tsf 7
  4. 196 Wje 7
  5. 197 Edward C. Robinson, Pe 7

Apartments and multifamily issued, 516 engineers

Where they work

The neighborhoods where Trylon Tsf files the most permits, and how many engineers count each one among their top 4 neighborhoods.

  1. 01 Financial District/South Beach 386 engineers count Financial District/South Beach among their busiest neighborhoods
  2. 02 Bayview Hunters Point 149 engineers count Bayview Hunters Point among their busiest neighborhoods
  3. 03 South of Market 204 engineers count South of Market among their busiest neighborhoods
  4. 04 Nob Hill 94 engineers count Nob Hill among their busiest neighborhoods

Questions for the first call

  1. Which of your recent San Francisco permits are closest to my project in type, size and neighborhood, and can I see the permit numbers?
  2. How long did those permits take from filing to issue, and what did plan check send back?
  3. Who on your team draws the set, who stamps it, and who answers the city's comments?

Other engineers for apartments and multifamily

Firms ranked near Trylon Tsf by permits issued for apartments and multifamily.

  1. 188 Bay City Mechanical Inc. 7 apartments and multifamily issued · 10.4 mo median for apartments and multifamily
  2. 189 Next Edge 7 apartments and multifamily issued
  3. 194 Lefler Engineering, Inc 7 apartments and multifamily issued
  4. 199 Acco Enginneered Sys 6 apartments and multifamily issued
  5. 200 Sfdpw 6 apartments and multifamily issued
  6. 201 James Li P.E. Consulting 6 apartments and multifamily issued
Sheet
S-417 No. 417 of 1,146
Drawing
Permit record, Trylon Tsf
Engineer
License
90242 check with BPELSG
Data as of
Oct 2026
Scale
Not to scale

Built only from public San Francisco Department of Building Inspection records (permits, permit contacts), updated 2026-10-20. It is not a review or an endorsement, and Trylon Tsf has not paid to be listed. Project addresses are never shown.

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