Washington Clean Buildings · Tier 2 guide

Is my building Tier 2?

Last checked against official sources on October 9, 2026.

Washington's Clean Buildings Performance Standard (CBPS) splits covered buildings into two tiers. Tier 2 is the newer group of mid-size commercial buildings and multifamily buildings, and its first report is due July 1, 2027. Here is how to tell, in a few minutes, whether a building is likely Tier 2.

The Tier 2 size rule

Commerce defines a Tier 2 covered building as either of these (Commerce, Tier 2 compliance):

• Non-residential: a building where the nonresidential, hotel, motel and dormitory floor areas add up to more than 20,000 gross sq ft but not more than 50,000 gross sq ft, excluding the parking garage area.
• Multifamily residential: a multifamily residential building with more than 20,000 gross sq ft, excluding the parking garage area. There is no upper size limit for multifamily in Tier 2.

Non-residential buildings over 50,000 sq ft are Tier 1, which has different rules and earlier deadlines (RCW 19.27A.200).

What counts as "multifamily"

State law defines a multifamily residential building as a covered building containing sleeping units or more than five dwelling units where occupants are primarily permanent (RCW 19.27A.200). Apartment buildings are the typical example.

Who is the "owner"?

The obligation sits with the building owner: the person or entity holding title to the building (or, on leased land, the entity holding title to the building). For condominiums subject to the standard, the owner is the owners' association (WAC 194-50-030). Many buildings are held by an LLC, so the legal owner may not be the name on the leasing sign.

Condos follow a different count

Individually owned condo units don't count toward the floor area. A condo building is covered when the association-owned common space (lobbies, hallways, mechanical rooms, elevator shafts, amenities) is over 20,000 sq ft, or when common space plus interconnected association-owned commercial space is between 20,000 and 50,000 sq ft (Commerce CBPS 034, Condominium Guidance). See our condo association guide.

Buildings that aren't covered or may be exempt

• Federal buildings and buildings owned by federally recognized tribes are not required to comply.
• A Tier 2 building may qualify for an exemption when one or more of these affect more than 50% of its square footage: no certificate of occupancy; no physical occupancy; unconditioned and semi-heated space; manufacturing or industrial use; agricultural use; pending demolition; financial hardship; or national security.
• Exemptions are applied for building by building in the Clean Buildings Portal, no QEM is needed to apply, and applications must reach Commerce no later than six months before the compliance date.

Source: Commerce, Tier 2 compliance and CBPS 028, Tier 2 compliance through exemption.

A 5-step check

1. Find the gross floor area without parking. Use building plans, the county assessor record, or (in Seattle) the city's public energy benchmarking data. These are estimates: the floor area your QEM calculates is what counts.
2. Decide the building type. Multifamily (more than five dwelling units or sleeping units, mostly permanent occupants), non-residential, or condo.
3. Apply the size rule above. Multifamily over 20,000 sq ft, or non-residential over 20,000 and up to 50,000 sq ft. For condos, count only association-owned common and commercial space.
4. Check for an exemption using the list above. If one may apply, read CBPS 028 before the six-month cutoff.
5. Confirm in the Clean Buildings Portal. Owners can log in, open the Tier 2 Data Pool tab and confirm (or deny) ownership of the buildings Commerce has listed for them (Commerce, Tier 2 compliance).

If the building is covered, the next questions are what you must submit and by when. That's in our deadline, penalties and incentive guide.