Bid guide
How to bid on Seattle City Hall Roof and Windows Replacement for the City of Seattle
What the City of Seattle is buying
The City of Seattle is seeking a contractor to replace the roof and windows at Seattle City Hall. This project also includes related building envelope repairs, such as green roof replacement, waterproofing, roof drainage repairs, and the installation of fall protection and bird deterrent systems. The base estimate for this work is $4,552,000, with four additional bid alternates listed.
This opportunity is for construction firms experienced in large-scale building envelope projects, particularly those involving municipal buildings and specialized roofing or window systems. The work is located at 600 4th Ave, Seattle, Washington.
Key dates and what happens at the deadline
This solicitation was published on August 26, 2026. The deadline for submitting your response is September 23, 2026, at 5:00 PM ET. All proposals must be submitted by this time.
It is important to submit your response well before the deadline to avoid any last-minute technical issues. Late submissions are typically not accepted.
Who this opportunity suits
This opportunity is suitable for construction companies with expertise in commercial roofing, window replacement, and building envelope repair. Experience with green roof systems, waterproofing, and working on public or historic buildings would be beneficial.
Firms with a strong track record in projects of similar scope and value, particularly those involving complex building systems and multiple bid alternates, are encouraged to consider this solicitation. The project falls under the general construction category.
How to respond
To access the full details and respond to this opportunity, you need to use the City of Seattle's procurement portal, OpenGov Procurement. First, locate the original source of the solicitation. When you click on it, OpenGov Procurement will perform a brief security check before loading the project page.
Once on the project page, you will need to sign in to your OpenGov account or create a free vendor account if you don't already have one. Signing in allows you to download plans, ask questions, join the planholders list, and submit your proposal. Any addenda or updates to the solicitation will also be communicated through OpenGov.
Tips for preparing a competitive response
Carefully review all project documents, including the full description, specifications, and any provided drawings. Pay close attention to the engineer's estimate for the base bid and understand the scope of each bid alternate. Clearly address how your firm meets the requirements for each component of the project, including specialized work like green roof replacement and fall protection systems.
Ensure your proposal is well-organized, clear, and directly addresses all requested information. Double-check all calculations, especially for the base bid and each alternate, to ensure accuracy. Consider any specific experience your team has with similar municipal projects or complex building envelope repairs that can highlight your qualifications. Submit your response well in advance of the deadline to prevent any technical submission issues.
See the live bid — deadline, agency details, and how to respond
Dates and requirements can change via addenda; always verify on the bid page and at the original source before responding.
View this bid on BiddingSimpleThis guide was prepared by BiddingSimple from the solicitation’s public posting. It is not official guidance from City of Seattle; the original posting controls.