Solar PV Request for Proposal (RFP #2627-0577) Solicitation 3: Cordata, DO, Happy Valley

Bellingham School District #501

Solar Design & Installation

Solicitation 3 — Cordata Elementary School, District Office, and Happy Valley Expansion

Request for Proposals

RFP #2627-0577

Proposal Due Date: Thursday, October 29, 2026, 3:00 PM Pacific

Solicited pursuant to RCW 39.04.290

Bellingham School District #501 Operations Department

1985 Barkley Blvd Bellingham, WA 98226

Owner’s Representative: Cascadia Renewables LLC

1. Introduction

1.01 Purpose

Bellingham School District #501 (the “District”) is soliciting proposals from qualified design-build contractors for the design, fabrication, and installation of rooftop photovoltaic (PV) systems at three District sites under a single contract:

• Cordata Elementary School, 4420 Aldrich Road, Bellingham, Washington 98226 (Whatcom County parcel #380212067442) — a new 100.34 kW DC / 80.00 kW AC system;

• District Office, 1985 Barkley Blvd, Bellingham, Washington 98226 (Whatcom County parcel #193765) — a new 70.76 kW DC / 60.00 kW AC system; and

• Happy Valley Elementary School, 1041 24th Street, Bellingham, Washington 98225 — a 34.80 kW DC expansion of the District’s existing 220.98 kW DC rooftop photovoltaic system, added to the existing inverters with no new alternating-current equipment and no new point of interconnection.

The selected Contractor will carry the design engineering through to issuance of construction documents and will construct, commission, and place all three systems in service. Each site is a separate generating facility with its own utility account, its own point of interconnection and its own Permission to Operate; the three are procured, contracted, scheduled and paid for as one project. See Section 6.07.

This Solicitation 3 is the third of an anticipated total of five solicitations to complete a ten-site District solar program, with projects running from 2026 through 2028. Proposers are encouraged to review the full program calendar in Section 3.04 when assessing their capacity to perform.

1.02 The District and the program

Bellingham Public Schools serves approximately 11,200 students and 1,400 staff across 22 main school buildings totaling more than 1.5 million square feet. In 2025, the District completed approximately 1 MW of rooftop solar across five schools as part of a previous program; the existing array at Happy Valley Elementary School is one of those installations. The current program will extend that work to ten additional sites and is being delivered under Washington State University (WSU) Energy’s Community Solar Expansion Program (CSEP).

1.03 Owner’s Representative and conflict of interest

Cascadia Renewables LLC (“CR”) serves as the District’s independent Owner’s Representative for this program.

CR prepared the technical bid specification, is administering this solicitation on the District’s behalf, and will provide design review, construction oversight, and commissioning oversight. CR also serves as one member of the evaluation panel detailed under Section 9.04. Every determination of responsiveness, responsibility, and award remains at the District’s discretion; determinations will be made and signed by the District pursuant to Sections 7.03 and 9.01.

CR, together with its subsidiaries and affiliates, is not a Proposer on this solicitation, holds no design-build contract for this work, and will not be a proposer, subcontractor, or equipment supplier on Solicitations 1 through 5 of this program. Neither CR nor any of its principals will hold a financial interest in any Proposer, proposed subcontractor, or equipment supplier in connection with this solicitation.

1.04 Funding and schedule

This project is funded by a WSU Energy Program CSEP incentive combined with the elective payment (“Direct Pay”) provision of the federal Investment Tax Credit (or “ITC”) under IRC §6417. The District is claiming the energy community bonus, which is location-based. Domestic content is encouraged but not required under this solicitation for modules, racking and balance of system. Power inverters and module-level power electronics are subject to Section 2.03. Federal prevailing wage, apprenticeship and prohibited foreign entity requirements bearing on the Credit are set out in Section 2.04.

Direct Pay eligibility depends on each system being placed in service on or before December 31, 2027. If that date is missed at a site, the credit attributable to that site is lost in full—there is no partial credit and no cure available to the District in such an event. The District has therefore set the (a) Substantial Completion and (b) Placed in Service dates in Section 12.01 well in advance of that deadline, so that the credit is not exposed to late-season utility processing. Proposers are strongly encouraged to read and understand Sections 12.01 and

12.02 carefully before pricing this work.

2. Procurement Authority and Method

2.01 Statutory authority

This solicitation is issued under and governed by RCW 39.04.290, which allows for the competitive bidding of building engineering systems. The selected contractor must provide final specifications and a bid price for the system, with all specifications subject to approval by the appropriate design, engineering, and/or public regulatory body. Chapter 39.80 RCW does not apply to the design of building engineering systems included in a contract under this section.

The selected Proposer is responsible for producing final specifications stamped by a Washington-licensed professional engineer and approved by the City of Bellingham as the authority having jurisdiction.

2.02 Method of award

This is a best-value procurement, not a low-bid procurement. The District will award the contract to the responsive, responsible Proposer with the highest total evaluated score under Section 9. Price is a scored, weighted element of that evaluation, but the District is not obligated to award to the lowest-priced Proposer.

This is a single award covering all three sites. The District will not award a site to one Proposer and another site to a different Proposer, and a proposal that prices fewer than all three sites will be rejected as non-responsive.

This procurement is not conducted through a small works roster and is not subject to RCW 39.04.155. All other public works requirements of Title 39 RCW apply, including but not limited to prevailing wages under Chapter

39.12 RCW, bonding under Chapter 39.08 RCW, retainage under Chapter 60.28 RCW, and the mandatory and supplemental bidder responsibility criteria of RCW 39.04.350 (Sections 7.01 and 7.03). The apprentice utilization requirements of RCW 39.04.320 and the subcontractor listing requirements of RCW 39.30.060 do not apply to this solicitation; see 8.04.

2.03 Prohibited foreign equipment – FCC Covered List

The work required for the program will include the use of power inverters and module-level power electronics.

Foreign-produced power inverters and module-level power electronics are included on the Federal Communications Commission’s (“FCC”) Covered List maintained under the Secure and Trusted Communications Networks Act of 2019 (Public Notice DA 26-786, WC Docket No. 18-89, ET Docket No. 21-232, EA Docket No.

21-233), except to the extent the Department of Homeland Security or the Department of War has granted a conditional approval for a specific power inverter or module-level power electronics.

Proposers must acquaint themselves with the definition of a power inverter and what qualifies as foreign-produced for purposes of the FCC Covered List, and exceptions or exclusions that may be applicable.

• As part of its proposal, a Proposer must:

• Certify in its proposal, on the form provided in the Contractor Response Template, that each power inverter and each module-level power electronic device it proposes either:

• is not foreign-produced (consistent with the definition applicable to the FCC Covered List);

• has been granted a Conditional Approval by the Department of War or the Department of Homeland Security; or

• held a valid FCC equipment authorization in effect on the proposal deadline and remains lawfully marketable in the United States;

• Re-certify the same at product submittal under Bid Specification Section 1.06.1, and again before the equipment is ordered;

• Notify the Owner’s Representative in writing within five (5) business days of becoming aware that any proposed or ordered device has been added to the Covered List, has had an equipment authorization denied, revoked or withdrawn, or has otherwise lost the status certified under subsection 1 above; and

• Substitute a device of equal or better performance meeting the Bid Specification and this Section, at no increase in the Contract Sum and no extension of the Contract Time, where a device previously certified under subsection 1 above cannot lawfully be installed.

• Basis of design and deviations. The Bid Specification names one (1) SolarEdge SE80K-US inverter at Cordata Elementary School and two (2) SolarEdge SE30K-US inverters at the District Office, with the SolarEdge C651U power optimizer at all three sites, as the basis of design. A Proposer offering any alternative inverter or module-level power electronic device must document with its proposal that the alternative satisfies subsection A.1 above. Approval of an alternative under Bid Specification Sections 2.05.5 and 2.03.3 does not waive this requirement. This Section applies to devices proposed or installed by the Contractor; it does not apply to the District’s existing inverters at Happy Valley Elementary School, which the Contractor is not required to replace. The module-level power electronics the Contractor installs on the Happy Valley expansion modules are within this Section.

• In addition to and separate from the requirements set forth in subsection A.1, the District additionally requires that power inverters and module-level power electronics be supplied by a manufacturer that is not headquartered in a country of concern. This criterion set forth in subsection C is separate from, and does not substitute for, subsection A, and a device may satisfy one and fail the other.

This Section 2.03 applies to power inverters and module-level power electronics. The advanced robotic devices addressed by the same Public Notice are not within the scope of this project.

2.04 Federal tax credit compliance — prevailing wage and apprenticeship, and prohibited foreign entity restrictions The District intends to claim the Clean Electricity Investment Credit under Section 48E of the Internal Revenue Code of 1986, as amended (the “Credit”), through the elective payment provision of Code Section 6417, together with the energy community bonus described in Section 1.04. Two sets of federal requirements bear directly on the Work and on how it should be priced. They are separate from, and additional to, the Washington public works requirements of Section 12.06 and the FCC Covered List requirements of Section 2.03.

A. Prevailing wage and apprenticeship. The increased credit amount ordinarily depends on compliance with the prevailing wage and apprenticeship requirements of Code Sections 48(a)(10) and 45(b)(8), as incorporated into the Credit by Code Sections 48E(d)(3) and (4) (the "PWA Requirements"). The maximum net output of each of the three facilities under this solicitation, measured in alternating current at the capacity limits in Section 6.01 and Bid Specification Section 1.04.3, is less than one megawatt. Each facility therefore qualifies for the increased credit amount under the one-megawatt exception in Code Section 48E(a)(2)(A), and the PWA Requirements do not apply to this Work. No federal prevailing wage determination, registered apprenticeship standard or PWA compliance declaration is sought from the Contractor, and Proposers must not price for any of them.

Washington prevailing wage obligations under Chapter 39.12 RCW apply independently of the Credit and are addressed in Section 12.06.

By submitting a proposal the Proposer certifies, on the form provided in the Contractor Response Template, that it will not design or construct any facility such that its maximum net output reaches one megawatt of alternating current, whether alone or combined with existing generating equipment at the same site; and that it will furnish, site by site, the records the District requires to substantiate the location, placed-in-service date and qualified basis of each facility.

B. Prohibited foreign entity restrictions. Because construction of this project begins after December 31, 2025, the Credit is subject to the prohibited foreign entity restrictions of Code Sections 7701(a)(51) and (52), as incorporated into the Credit by Code Sections 48E(b)(6), (c)(3) and (d)(6), including the payment rules of Code Section 7701(a)(51)(D)(i)(II) and (ii) and the material assistance rules of Code Section 7701(a)(52) (the “PFE Restrictions”).

By submitting a proposal the Proposer certifies, on the form provided in the Contractor Response Template, that it, its subcontractors and its suppliers are able to comply with the PFE Restrictions, and that for every manufactured product and eligible component incorporated into the Work it will deliver (1) a supplier certification in substantially the form issued with this RFP, signed under penalty of perjury and stating the supplier’s employer identification number or foreign equivalent (Bid Specification Section 2.01.8.3), and (2) the direct cost information the District requires to compute the material assistance cost ratio for the Work, reported separately for each of the three sites. The Proposer and the District must each retain these records for six (6) years.

C. Timing and substitution. Certifications under this Section are re-confirmed at product submittal under Bid Specification Sections 2.01.8 and 1.06.2.15 and again before equipment is ordered, on the same terms as Section

2.03. Where a product previously certified can no longer be supplied in compliance with this Section, the Contractor must substitute a product of equal or better performance meeting the Bid Specification, at no increase in the Contract Sum and no extension of the Contract Time.

D. Contract liability. The form of design-build agreement published by addendum under Section 12 will state the Contractor’s liability to the District for any reduction, disallowance or recapture of the Credit, and any associated penalties or interest, attributable to a failure by the Contractor, its subcontractors or its suppliers to meet the PWA Requirements or the PFE Restrictions. That liability is measured site by site, because each of the three sites is separate energy property with its own credit basis. Proposers should price this work on that basis.

E. Questions. The sample supplier certification form is issued with this RFP through Bonfire. A Proposer that believes any requirement of this Section cannot be met as specified must raise it through the Q&A process under Section 5.02 before the question deadline in Section 3.02.

3. Procurement Schedule

3.01 Notice

Notice of this solicitation is published in at least one newspaper of general circulation within the District once each week for two consecutive weeks, on Wednesday, September 30, 2026, and Wednesday, October 7, 2026, in accordance with RCW 28A.335.190(1). The RFP and all exhibits are available through Bonfire on the first publication date.

3.02 Key dates

Event Date

First publication of notice; RFP issued Wednesday, September 30, 2026

Second publication of notice Wednesday, October 7, 2026

Mandatory site walk — registration requested Thursday, October 8, 2026, 8:30 AM

Form of design-build agreement published by addendum

On or about Friday, October 9, 2026

Deadline for written questions; deadline to request modification of supplemental criteria (Section

Friday, October 16, 2026, 3:00 PM

Event Date

7.03); deadline to protest solicitation terms (Section 13.01)

Addendum issued with question responses Wednesday, October 21, 2026

PROPOSALS DUE Thursday, October 29, 2026, 3:00 PM

Evaluation and scoring October 30 – November 5, 2026

Finalist interviews (if held) November 9 – November 11, 2026

Board of Directors approval Thursday, December 17, 2026

Contract execution and Notice to Proceed On or about Friday, December 18, 2026

The District reserves the right to modify this schedule of Key Dates, in part or in full, by addendum.

3.03 Performance milestones

Unless a milestone is expressly identified as site-specific, it applies to the Work as a whole and is met only when it has been met at all three sites.

Milestone Date

30% design submittal — all three sites, including the structural and roof loading submittals required by Bid Specification Section 1.06.4 and the existing system integration plan for Happy Valley required by Bid Specification Section 1.06.2.16

Within 30 days of Notice to Proceed

PSE Schedule 150 interconnection applications filed — Cordata Elementary School and District Office; written confirmation from PSE of the treatment of the Happy Valley expansion under Bid Specification Section 1.04.15.2

Within 45 days of Notice to Proceed

60% issued-for-permit design submittal; roof access and fall arrest provisions finalized at each site (Section 6.05)

Within 60 days of Notice to Proceed

90% issued-for-construction design submittal On or before Monday, March 15, 2027

Building and electrical permits issued — all three sites

On or before Friday, April 9, 2027

On-site construction begins On or after Monday, April 12, 2027 (see Section 12.12)

Happy Valley Elementary School expansion Placed in Service (site-specific — sequenced first under Section 6.07)

On or before Friday, June 11, 2027

Recovery schedule trigger — forecast Placed in Service of any site later than August 15, 2027 (Section 12.03)

Notice within 5 business days; recovery schedule within 10 business days

SUBSTANTIAL COMPLETION — all three sites Thursday, July 15, 2027

PLACED IN SERVICE — PSE Permission to Operate and energization at all three sites

On or before Sunday, August 15, 2027

Final completion, closeout, and final acceptance Friday, October 29, 2027

3.04 Program calendar — remaining solicitations

The following is provided for reference purposes only and so that Proposers can plan capacity across the program. Dates and capacities other than those for this Solicitation 3 are targets and are subject to change in the District’s sole discretion.

Solicitation Sites Estimated Capacity (DC) Advertised Completion

1 Squalicum High School 498.22 kW Sept 23, 2026 Jul 2027

2 Sehome High School 557.38 kW Sept 23, 2026 Jul 2027

3 Cordata Elementary, District Office, Happy Valley Expansion

205.90 kW Sept 30, 2026 Jul 2027

4 Bellingham High School, Whatcom Middle School

675.12 kW Aug 2027 Aug 2028

5 Parkview Elementary, Birchwood Elementary

515.04 kW Aug 2027 Aug 2028

A Proposer may respond to more than one solicitation. Award of one solicitation does not preclude award of another; however, demonstrated capacity to perform concurrent work is scored under Section 9.

The Solicitation 1 and Solicitation 2 site walks were held on Thursday, October 1, 2026. Proposals for those solicitations are due on Thursday, October 22, 2026, one week before proposals for this Solicitation 3.

4. Mandatory Site Walk

4.01 Attendance and registration

Attendance at the site walk on Thursday, October 8, 2026, is mandatory. Attendance must be by an employee or officer of the Proposer or of a firm named in the proposal as a joint venture partner. Attendance by a proposed subcontractor or outside consultant does not satisfy this requirement. A proposal from a firm that did not attend will be rejected as non-responsive.

The site walk visits all three sites in one sequence. A firm must attend the full sequence. Attendance at part of the sequence only does not satisfy this Section.

Registration for the site walk is requested by 3:00 PM on Monday, October 5, 2026, via Bonfire, so that badges can be prepared. A firm that has not registered by that time is not excluded: it may attend by notifying the District through Bonfire at any time before the site walk begins, or by presenting itself at the start location, subject to the access requirements below.

● Start location: Happy Valley Elementary School, 1041 24th Street, Bellingham, WA 98225.

● Arrival and introductions: 8:30 AM at Happy Valley Elementary School. The sequence moves by private vehicle from Happy Valley Elementary School to Cordata Elementary School and then to the District Office, and concludes at approximately 1:15 PM at the District Office.

● Parking at Happy Valley Elementary School, 1041 24th Street: when you pull into the parking lot, follow the curved road on the right side all the way up, curve around, then keep going back toward the street and park on the straight edge of the road. Depending on the number of vehicles, you may pull clear down to the black mailbox area. Park on the west corner of the lot furthest from the school. See the Happy Valley site walk plan in Exhibit F.

● Parking at Cordata Elementary School, 4420 Aldrich Road: park in the south corner of the lot, furthest from the school building, and assemble at the generator enclosure at the south end of the parking area.

See the Cordata Elementary site walk plan in Exhibit F.

● Parking at the District Office, 1985 Barkley Blvd: do NOT park in the lot signed BPS Parking; that lot is reserved and space is limited. Park in BPS Event Parking #1, on the south side of Barkley Blvd, and follow the marked walk path north to the District Office plaza entrance. The parking areas and the walk path are shown on the District Office site walk plan in Exhibit F.

● Exhibit F reproduces the site walk plan for each site, showing parking, the assembly point and the route between the generator, transformer, main service entrance, electrical room and the roof areas to be assessed. Exhibit F is part of this RFP. Attendees are encouraged to review it before arriving at each site.

● Attendees must wear company-logo clothing or a high-visibility vest at all times.

● Roof access will be provided at all three sites. Attendees must be capable of interior stair and ladder access and must comply with District fall-protection direction. At Happy Valley Elementary School attendees will be taken onto roof areas adjacent to an energized photovoltaic array and must not handle any part of that array; at Cordata Elementary School the three roof sections are reached from separate interior access stairs and ladders in equipment service rooms distributed through the building; at the District Office the roof is reached by interior stairs to a rooftop access door, with a ladder to the raised service mezzanine.

● If attendance exceeds 30, the group will be split into two rotations.

All questions must be submitted via Bonfire to ensure uniform responses that are available to all potential proposers. Oral statements made in response to questions raised during the site walk are not binding on the District.

4.02 Site walk anticipated schedule

Time Activity

8:30 – 8:50 AM Arrival at Happy Valley Elementary School, 1041 24th Street. Park on the west corner of the lot furthest from the school, following the curved road as described in Section

4.01 and Exhibit F. Check-in, introductions, agenda review.

8:50 – 9:25 AM Happy Valley — roof: the existing 220.98 kW DC array, the two roof faces proposed for the 34.80 kW DC expansion, the existing racking and attachment detail to be matched, and the existing SolarEdge inverters, combiner and monitoring equipment

9:25 – 9:45 AM Happy Valley — generator, transformer and main service entrance; main electrical room; staging and access review;

closing questions for this site

Time Activity

9:45 – 10:00 AM Travel to Cordata Elementary School, 4420 Aldrich Road.

Park in the south corner of the lot, furthest from the school building (Exhibit F)

10:00 – 10:35 AM Cordata — exterior and primary electrical room: PSE pad-mount transformer and CT panel on the northwest corner of the southernmost building, PSE CT meter, generator in the south parking area; 1200 A main switchboard, 1200 A main OCPD, integrated PCC, automatic transfer switch X/XE and sub-panels

LXEA/HXEA/HA/LA/L1/HXA

10:35 – 11:10 AM Cordata — roofs: the three proposed array roof sections, the new Imetco Series 300 standing seam metal roof assembly and seam profile, roof access locations, existing walkways and tie-off anchors, and internal conduit routing candidates between buildings

11:10 – 11:30 AM Cordata — staging and access review: staging area adjacent to the generator, lift and crane positioning; closing questions for this site

11:30 – 11:45 AM Travel to the District Office, 1985 Barkley Blvd. Park in BPS Event Parking #1 and walk the marked path north to the plaza entrance (Exhibit F)

11:45 AM – 12:20 PM District Office — lower-level main electrical room, entered from the exterior door on the south side off Barkley Blvd:

1200 A main switchboard, 1200 A main OCPD, PSE meter on the MDP, 800 A automatic transfer switch and panel HXE; PSE 500 kVA pad-mount transformer on the southwest exterior corner; Kohler generator enclosure at the northwest corner of the north parking area

12:20 – 1:00 PM District Office — roof: the uppermost flat roof section and the western and eastern lower flat roof sections, the 2022 TPO membrane and the moss and bubbling conditions identified in Bid Specification Section 1.03.12, rooftop equipment and vents, the raised service mezzanine proposed for the inverters, and the wall, roof and floor penetration routes down to the lower-level electrical room

1:00 – 1:15 PM District Office — staging and access review; closing questions for all three sites, held at the plaza entrance, and adjourn

Travel between sites is by attendees’ own vehicles. Attendees are responsible for arriving at each site within the window above; the group will not wait.

4.03 Site briefing — conceptual design and service

The following summarizes conditions Proposers are encouraged to examine during the site walk. Nothing set forth below is a substitute for the Bid Specification or the feasibility studies issued with this RFP through Bonfire, and it does not relieve the Contractor of the field verification obligations in Bid Specification Section 3.01.

4.03.1 Happy Valley Elementary School — expansion

Item Condition

Conceptual system 34.80 kW DC added to the District’s existing 220.98 kW DC array; (60) Heliene 144HC M10 NTYP SL Bifacial 580 W modules in two (2) strings of thirty (30), with (60) SolarEdge C651U optimizers, terminated into the existing SolarEdge SE120K-US inverters. No new inverters, no new AC equipment, no new point of interconnection. Combined array 255.78 kW DC

Existing system 220.98 kW DC / (381) modules installed in 2025 under a Washington Department of Commerce EPIC award, served by two (2) existing SolarEdge SE120K-US inverters at 480 V. The system is in service and under manufacturer and workmanship warranties that must survive this work

Expansion arrays Two roof faces, both at 163° azimuth: a fourteen (14) module area at 10° pitch and a forty-six (46) module area at 7° pitch. Annual solar access 100% and 97% respectively;

weighted TSRF across the expansion arrays 87.2%

Attachment The Contractor shall match the racking system, attachment detail and flashing method of the existing array, confirmed in writing by the racking manufacturer and by the roof membrane manufacturer. See Bid Specification Sections

1.04.13.3 and 1.04.15

Production Estimated 35,218 kWh in the first year for the expansion arrays alone, modeled in Aurora against an 8760 hourly weather file

Interconnection No new interconnection application is anticipated, because no alternating-current capacity is added. The Contractor must nonetheless obtain and deliver PSE’s written confirmation of the treatment of the added direct-current capacity, and file any amendment or notification PSE requires, under Bid Specification Section 1.04.15.2

Metering and reporting The expansion shares the existing revenue meter, PSE Z13591576, with the base system. String-level SolarEdge reporting is required so that the production of the expansion arrays can be reported separately for WSU Community Solar Expansion Program purposes. See Bid Specification Section 2.06.4

Utility tariff PSE Schedule 667. The site is not net metered

Access and staging Roof access and staging as at the other elementary sites;

work is adjacent to an energized array and the Site Specific Safety Plan must address that

4.03.2 Cordata Elementary School

Item Condition

Conceptual system 100.34 kW DC / 80.00 kW AC; (173) Heliene 144HC-580 M10 modules; (1) SolarEdge SE80K-US inverter with (173) C651U optimizers

Attachment Non-penetrating flush mount rail system clamped to standing seam; IronRidge XR100 with S-5! or equivalent non-penetrating seam clamps is the basis of design

Layout Three (3) arrays: Roof 1, the southernmost 219°-facing roof at 10° pitch; Roof 2, the 189°-facing roof at 10° pitch; and Roof 3, the northernmost 204°-facing roof at 18° pitch, preserving IFC fire setbacks and 4-foot access pathways.

No modules are proposed on north-facing roofs

Roof New standing seam metal roof installed by the District in 2026 over the original 2011 composition shingle assembly, under a separate District contract. The assembly is Imetco Series 300 symmetrical standing seam metal roofing, standard profile, with a one-inch symmetrical seam cap and a nominal seam height of 2-3/8 inches, as described in Bid Specification Section 1.03.12.1. The Contractor’s clamp selection must be listed for that profile and approved in writing by the panel manufacturer

Roof loading Roof loading capacity 469 plf with more than 200 plf additional available; conceptual PV loading 2.6 psf. Bid Specification Section 1.04.13 caps the complete array at

4.00 psf distributed dead load

Service 480Y/277V 3-phase; PSE pad-mount transformer co-located with the PSE meter and CT panel at the northwest corner of the southernmost building; 1200 A main switchboard and 1200 A main OCPD

Interconnection headroom 240 A available under the 120% rule, against which the conceptual design carries a 125 A solar interconnection breaker. Feasibility-stage hosting capacity at this feeder was reported as 0.00 MW net of generation in queue, measured against direct transfer trip thresholds that are not ordinarily applied to a net metered inverter-based facility of this size interconnected under PSE Schedule 150; see Bid Specification Section 2.02.4 and Section 12.09

Primary utility meter PSE P177888912, on a northwest-facing exterior wall adjacent to the outdoor transformer. Utility tariff PSE Schedule 25

Standby generator Cummins 175 kW, 480Y/277V, 3-phase diesel, through an automatic transfer switch serving dedicated critical loads.

Backed-up load panels, not whole-site backup

Shading The proposed array locations are all southeast-facing with no material shading. Conceptual design achieves 91.0%

TSRF

Access and staging The three roof sections are reached from separate interior access stairs and ladders in equipment service rooms distributed through the building. Roof height requires mechanical lifting; the staging area is busy and may not accommodate a telehandler of sufficient reach, and a crane may be required. An external man-lift or forklift is recommended so that routine material movement does not pass through occupied areas

Array conduit The system may require trenching or exterior routing between buildings to reach the single inverter on the southernmost building. Internal routing is permitted subject to Bid Specification Section 2.07.2

4.03.3 District Office

Item Condition

Conceptual system 70.76 kW DC / 60.00 kW AC; (122) Heliene 144HC-580 M10 modules; (2) SolarEdge SE30K-US inverters with (122) C651U optimizers

Attachment Ballasted with seismic restraint anchors; PanelClaw FR Pro with U-Anchor seismic anchors, 9-degree tilt, 17-inch inter-row spacing, is the basis of design. Seismic anchors penetrate the membrane

Layout Four (4) individual arrays: (60) modules on the uppermost flat roof section, (20) on the western lower flat roof section and (42) on the eastern lower flat roof section, preserving IFC fire setbacks and 4-foot access pathways to all rooftop equipment and vents

Roof loading Roof loading capacity 25.0 psf with 6.5 psf additional available for PV; the feasibility estimate for the conceptual array is 5.0 to 6.5 psf, which does not clear the available capacity with design margin. Bid Specification Section

1.04.13 caps the complete array at 5.00 psf distributed dead load and Section 1.04.13.1 requires ballast to be proportioned against mechanical attachment to achieve it

Roof 2022 TPO membrane, in service, not being replaced, under a live manufacturer warranty. The site assessment recorded areas of moss growth and areas of membrane bubbling or separation. Remediation and the remaining-useful-life confirmation are District scope under Section 6.05

Service 480Y/277V 3-phase; PSE 500 kVA pad-mount transformer on the southwest exterior corner along Barkley Blvd; 1200 A main switchboard and 1200 A main OCPD in the lower-level main electrical room

Interconnection headroom 240 A available under the 120% rule, against which the conceptual design carries a 100 A solar interconnection breaker. PSE hosting capacity 0.42 MW (0.92 MW less 0.50 MW generation in queue); no direct transfer trip upgrades required at 60.00 kW AC

Primary utility meter PSE P157453238, located on the main distribution panel in the lower-level main electrical room. Utility tariff PSE Schedule 25

Standby generator Kohler 300 kVA diesel, 480Y/277V, interconnecting to the 1200 A MDP (H1) through an 800 A automatic transfer switch feeding the 1000 A panel HXE, with load shedding.

Backed-up load panels, not whole-building backup

Shading Limited rooftop shading from the two elevated roof sections, avoidable by layout. No surrounding trees or buildings. Conceptual design achieves 89.0% TSRF

Access and staging The roof is reached by interior stairs to a rooftop access door, with a ladder to the raised service mezzanine. Roof height requires mechanical lifting; an external man-lift or forklift is recommended so that routine material movement does not pass through occupied office areas. The building operates year-round

Array conduit Wall penetrations into the raised service mezzanine where the inverters are proposed, plus wall and internal roof and floor penetrations to reach the lower-level main electrical room

5. Communications, Questions and Addenda

5.01 Single point of contact

From the date this RFP is issued until the Notice of Intent to Award, all communication regarding this solicitation must be submitted through Bonfire. Proposers must not contact District staff, school principals, site staff, Board members, or the Owner’s Representative directly regarding this solicitation. Unauthorized contact may result in rejection of the proposal.

This restriction does not limit a Proposer’s right to attend or comment at an open public meeting of the Board of Directors under Chapter 42.30 RCW, to request modification of supplemental responsibility criteria under Section 7.03, to appeal a determination of non-responsibility under Section 7.03, to protest under Section 13.01, or to communicate with the District on matters unrelated to this solicitation.

5.02 Questions and responses

Written questions are due through Bonfire by 3:00 PM on Friday, October 16, 2026. All questions and the District’s responses will be published by addendum to all registered Proposers, without attribution, on or about Wednesday, October 21, 2026. Proposers are strongly encouraged to submit questions early so that supporting documentation can be gathered before the response deadline.

5.03 Addenda

Only written addenda issued by the District modify this RFP. Oral statements made at the site walk or elsewhere are not binding. Proposers must acknowledge receipt of all addenda in their proposal. Addenda are issued solely through Bonfire.

6. Project Scope and Budget

6.01 Site summary

The Work comprises three sites under one contract. Capacities, production floors and loading limits are site-specific and are stated separately below. Full technical requirements are in the Solicitation 3 Bid Specification, issued as Exhibit A to this RFP.

6.01.1 Cordata Elementary School

Parameter Requirement

Site Cordata Elementary School, 4420 Aldrich Road, Bellingham, WA 98226

Minimum DC capacity 100.34 kW DC

AC capacity Exactly 80.00 kW AC — both a minimum and a maximum. In no event may the system be capable of generating more than

100.00 kW AC; see Section 6.04 and Bid Specification Section 1.04.3

Minimum first-year production 105,714 kWh

Site annual consumption (reference) Approximately 401,350 kWh

Mounting Non-penetrating clamped attachment to the standing seam metal roof installed by the District in 2026. The complete array must not exceed 4.00 psf distributed dead load; see Bid Specification Section 1.04.13

Electrical service 480Y/277V, 3-phase; PSE pad-mount transformer; 1200 A main switchboard and 1200 A main OCPD; 240 A available for PV under NEC 705.12

Interconnection PSE Schedule 150 net metering. The system is rated at or below 100 kW AC and is eligible for net metering under PSE’s tariff

Sales tax status Exempt at point of sale under RCW 82.08.962(1)(e). See Section 6.04

6.01.2 District Office

Parameter Requirement

Site Bellingham Public Schools District Office, 1985 Barkley Blvd, Bellingham, WA 98226

Minimum DC capacity 70.76 kW DC

AC capacity Exactly 60.00 kW AC — both a minimum and a maximum. In no event may the system be capable of generating more than

100.00 kW AC; see Section 6.04 and Bid Specification Section 1.04.3

Minimum first-year production 75,161 kWh

Site annual consumption (reference) Approximately 604,800 kWh

Mounting Ballasted with seismic restraint anchors on an existing (2022) TPO membrane roof. The complete array must not exceed

5.00 psf distributed dead load; see Bid Specification Section 1.04.13

Parameter Requirement

Electrical service 480Y/277V, 3-phase; 500 kVA PSE pad-mount transformer;

1200 A main switchboard and 1200 A main OCPD; 240 A available for PV under NEC 705.12

Interconnection PSE Schedule 150 net metering. The system is rated at or below 100 kW AC and is eligible for net metering under PSE’s tariff

Sales tax status Exempt at point of sale under RCW 82.08.962(1)(e). See Section 6.04

6.01.3 Happy Valley Elementary School — expansion

Parameter Requirement

Site Happy Valley Elementary School, 1041 24th Street, Bellingham, WA 98225

Minimum DC capacity added 34.80 kW DC, bringing the combined array to 255.78 kW DC

AC capacity No alternating-current capacity is added. The existing SolarEdge SE120K-US inverters are retained unchanged and the existing point of interconnection is unchanged. The Contractor must not add, replace or re-rate any inverter

Minimum first-year production 35,218 kWh, for the expansion arrays alone

Mounting Matching the racking system, attachment detail and flashing method of the existing array, confirmed in writing by the racking manufacturer and the roof membrane manufacturer;

see Bid Specification Sections 1.04.13.3 and 1.04.15

Electrical Two (2) strings of thirty (30) modules with module-level power electronics, terminated into spare direct-current input capacity on the existing inverters, within the manufacturer’s published string voltage, current and optimizer limits

Interconnection No new interconnection application is anticipated. The Contractor must obtain PSE’s written confirmation of the treatment of the added direct-current capacity and file any amendment or notification PSE requires; see Bid Specification Section 1.04.15.2

Sales tax status Taxable. The combined generating facility at this site is rated above 100 kW AC, so the point-of-sale exemption in RCW 82.08.962(1)(e) is not available for this scope. See Section 6.04

6.02 Maximum Allowable Construction Cost

The Maximum Allowable Construction Cost (MACC) for the Work is $514,100, allocated as follows:

Site MACC

Cordata Elementary School $249,900

District Office $184,200

Happy Valley Elementary School expansion $80,000

Site MACC

TOTAL $514,100

Because the Cordata Elementary School and District Office scopes are exempt from Washington retail sales tax at point of sale, and because sales tax on the Happy Valley Elementary School scope is excluded from the Not-to-Exceed price and paid separately by the District under Section 6.04, the MACC and the Not-to-Exceed price required by Section 6.03 are stated on the same basis and are directly comparable. A proposal above the MACC is not automatically non-responsive; the District may negotiate scope or price with the highest-ranked Proposer under Section 11.01 before award. Proposers should nonetheless treat the MACC as the District’s funded ceiling.

The per-site allocation above is the District’s funding basis and is used for grant reporting and for the site-by-site credit basis described in Section 2.04.D. It is not a per-site ceiling; a Proposer may allocate its price among the sites as its estimate requires, provided the allocation in Section D.1 of the Contractor Response Template is a true reflection of the cost of the work at each site.

6.03 Not-to-Exceed pricing and contingency

Proposers must state a single Not-to-Exceed (“NTE”) price for the Work as a whole, together with the portion of that price attributable to each of the three sites. The NTE price must include the cost of integrating the Happy Valley expansion with the District’s existing photovoltaic system under Bid Specification Section 1.04.15, the cost of all mechanical attachments, seismic anchors and associated roofing work required to meet the roof loading limits in Bid Specification Section 1.04.13, the cost of mobilizing separately to three sites, and the Proposer’s own contingency. No exclusions from the NTE price will be accepted. Anything a Proposer excludes from its base price must be covered by the Proposer’s contingency and/or its fee, within the NTE.

The NTE price is stated exclusive of Washington retail sales tax; see Section 6.04.

6.04 Washington retail sales tax

Cordata Elementary School and the District Office. Each of these systems is a solar energy system capable of generating no more than one hundred kilowatts AC of electricity. Machinery and equipment used directly in generating electricity at each site, and the labor and services rendered in respect to installing that machinery and equipment, are exempt from Washington retail sales tax at the point of sale under RCW 82.08.962(1)(e). This is a point-of-sale exemption, not a remittance: the District will furnish the Contractor with an exemption certificate in the form and manner prescribed by the Department of Revenue, and the Contractor must not charge sales tax on the exempt portion of the Work.

The exemption for labor and services under RCW 82.08.962(1)(e)(ii) is available only if the seller, at the time of the sale for which the exemption is claimed, (A) holds a certificate of registration under Chapter 18.27 RCW, (B) holds a current Washington unified business identifier number, (C) possesses proof of Title 51 RCW industrial insurance coverage for its employees working in Washington, an Employment Security Department number under Title 50 RCW, and a state excise tax registration number under Title 82 RCW, and (D) has had no findings of violation of federal or state wage and hour laws or regulations in a final and binding order by an administrative agency or court of competent jurisdiction in the past twenty-four months. Every Proposer must certify to those four conditions in Section B of the Contractor Response Template. That certification is a supplemental bidder responsibility criterion under Section 7 and a continuing contractual obligation: the Contractor must maintain each condition through final payment and must notify the District in writing within five

(5) business days of any event that causes it to fail any of them. The Contractor is responsible for any sales tax, interest and penalty the District incurs because the Contractor did not meet those conditions at the time of a sale.

Proposers should note that condition (D) applies to the entity making the sale. A Proposer that cannot certify condition (D) should raise it through the Q&A process under Section 5.02 before the question deadline rather than at award.

Happy Valley Elementary School. The existing generating facility at this site is rated above one hundred kilowatts AC. The combined facility as expanded is therefore not a solar energy system capable of generating no more than one hundred kilowatts AC, and the point-of-sale exemption in RCW 82.08.962(1)(e) is not available for the expansion scope. Proposers must state the Happy Valley portion of the NTE price exclusive of Washington retail sales tax, and must identify separately, in Section D of the Contractor Response Template, the portion of that price that is a taxable retail sale. Washington retail sales tax on the Happy Valley scope, at the City of Bellingham combined rate in effect at the time of each sale, will be added to the Contract Sum at cost and paid by the District. It will not count against the NTE price and will not be included in the price scored under Section

9.03. The District has requested a written determination from the Department of Revenue on the treatment of an expansion to an existing generating facility under RCW 82.08.962. If that determination establishes a different treatment before award, the District will state it by addendum; if it issues after award, the Contract Sum will be adjusted by change order to reflect it, without markup.

6.05 Owner-furnished work

The District will furnish the following at its own cost before PV installation at the site concerned. Contractors must not include this scope in their pricing.

Cordata Elementary School

• Replacement of the original composition shingle roof with a standing seam metal roof assembly, completed under a separate District contract. The assembly, seam profile and seam spacing are described in Bid Specification Section 1.03.12.1 and in the roof project manual issued with this RFP through Bonfire.

• Roof cleaning prior to PV installation. Spot cleaning at the point of attachment remains the Contractor’s responsibility per best practice.

• Permanent fall arrest anchors and permanent roof access ladders.

District Office

• Remediation of the membrane conditions identified in Bid Specification Section 1.03.12.2, under a separate District contract, together with written confirmation from the original installing roofer or the membrane manufacturer that the roof sections receiving PV have not less than ten (10) years of remaining useful life.

• Roof cleaning prior to PV installation, including removal of moss and biological growth from the roof sections receiving PV. Spot cleaning at the point of attachment remains the Contractor’s responsibility per best practice.

• Permanent fall arrest anchors and permanent roof access ladders.

Happy Valley Elementary School

• Roof cleaning of the expansion array areas prior to PV installation.

Coordination on anchor and ladder placement is mandatory, not optional. Anchor and ladder locations at Cordata Elementary School and the District Office will not be finalized until the Contractor’s 60% issued-for-permit design for that site is approved, so that the fall protection system suits the released array layout. The District will not install anchors or ladders before that approval without the Contractor’s written concurrence. Fall protection provisions already installed at Happy Valley Elementary School with the existing array are fixed and are not subject to this coordination.

6.06 Bid alternates

The District has identified the alternates listed below. Proposers must price each alternate separately on the Contractor Response Template at Section D.8. Alternate pricing is stated in addition to the Not-to-Exceed price and is not included in the NTE price scored under Section 9.03. The District may accept or reject any alternate, in whole or in part, and site by site, in its sole discretion at award, and acceptance or rejection of an alternate does not change the NTE price or any schedule milestone. Alternate pricing is stated on the same tax basis as the NTE price under Section 6.04 and must be held firm on the same terms as the NTE price under Section 8.02.

Alternate 1 — Load monitoring. Building load (consumption) monitoring integrated with the photovoltaic monitoring platform, priced separately for Cordata Elementary School and for the District Office. Bid Specification Sections 2.06.5 and 3.12.1. Photovoltaic production monitoring is included in the base bid and is not part of this alternate. Load monitoring is not sought at Happy Valley Elementary School.

Alternate 2 — Module cleaning. Annual cleaning of all photovoltaic modules for two (2) years following Substantial Completion, priced separately for each site. At Happy Valley Elementary School the alternate covers the complete combined array, not the expansion modules alone. Bid Specification Section 3.12.2.

6.07 Multi-site delivery, sequencing and site acceptance

The Work is three separate generating facilities delivered under one contract. The following governs how they are delivered.

A. Sequencing. The Happy Valley Elementary School expansion is the least complex scope and is sequenced first. The Contractor must achieve Placed in Service at Happy Valley Elementary School on or before June 11, 2027, as stated in Section 3.03. The Contractor may sequence Cordata Elementary School and the District Office in either order and may overlap them, subject to Section 12.12 and to the milestone dates in Section 3.03.

B. Single contract, separate facilities. Each site has its own utility account, its own point of interconnection, its own permit set and its own Permission to Operate, and each is separate energy property for federal tax credit purposes.