20260515Final_Order_No_37042.pdf

Office of the Secretary
Service Date
May 15,2026
BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF AVISTA ) CASE NO.AVU-E-26-02
CORPORATION'S ANNUAL RATE )
ADJUSTMENT FILING FOR ITS ELECTRIC ) ORDER NO. 37042
LINE EXTENSION SCHEDULE 51 )
On March 6, 2026, Avista Corporation, doing business as Avista Utilities ("Company")
applied to the Idaho Public Utilities Commission ("Commission") requesting approval to update
costs and make administrative changes to the Company's Electric Line Extension Schedule 51
("Schedule 51"), effective May 15, 2026 ("Application").
On March 30, 2026, the Commission issued a Notice of Application and Notice of
Modified Procedure, establishing public comment and Company reply deadlines. Order No.
36985. No petitions to intervene were filed. Staff filed the only comments.
Based on our review of the record, we issue this Final Order approving the Company's
request to update costs and make administrative changes to its Schedule 51, effective May 15,
2026.
THE APPLICATION
The Company requested approval to update the costs of, and make administrative changes
to,its Schedule 51,and for the changes to take effect May 15,2026.Application at 1.The Company
represented Schedule 51 establishes the estimated costs for electrical infrastructure regularly used
in extending electrical service, such as transformers and conduit.Id. at 2. The Company stated that
the estimated costs for Schedule 51 were determined from the recent average costs of the electrical
infrastructure. Id. The Company did not propose changing the average costing principle used to
determine the estimated costs in Schedule 51.Id.
The Company requested approval to update its allowances in Schedule 51 for incoming
commercial, industrial, and residential customers. Id. at 3. The Company represented that the
revised allowances were calculated by using the embedded-cost methodology approach. Id. The
Company explained the approach ensures that the cost of distribution/terminal facilities for each
new customer is similar to the costs of the same infrastructure already allocated for in the
Company's base rates. Id. New customers will have to pay for costs that exceed the updated
ORDER NO. 37042 1

allowances. Id. The Company represented the embedded-cost calculation was based on the Cost-
of-Service study approved in Order No. 36741.Id. The Company proposed the following changes
to the allowances:
Service Schedule Existing Proposed
Schedule 1 Individual Customer(per unit $2,545 $2,755
Schedule 1 Duplex (per unit $2,035 $2,205
Schedule 1 Multiplex(per unit $1,530 $1,655
Schedule 11/12 (per kWh) $0.19912 $0.21041
Schedule 21/22 (per kWh $0.18388 $0.20083
Schedule 31/32 (per kWh $0.32929 $0.35568
Id.
The Company also requested approval to update the average costs for primary circuits,
secondary circuits, service circuits, and transformers. Id. at 4. The Company proposed the
following updates to the average costs:
Present Proposed
Overhead Primary Circuit
Fixed Cost $5,536 $5,952
Variable Costs $11.20 $12.04
Underground Primary Circuit
Fixed Costs $2,583 $2,754
Variable Costs $13.55 $14.31
Underground Secondary Circuit
Fixed Costs $647 $688
Variable Costs $12.75 $13.18
Overhead Secondary Circuit
Fixed Costs $2,279 $2,466
Overhead Service Circuit $5.06 $5.56
Underground Service Circuit $10.29 $10.78
Overhead Transformer $5,308 $5,222
Padmount Transformer $10,003 $9,134
Id. The Company represented that the increase in average costs was due to higher overhead and
vehicle costs. Id. Higher overhead costs were due to increased costs for labor and benefits. Id. at
5. Higher vehicle costs were due to expenses for maintenance and repair of the Company's fleet
vehicles and higher fuel costs. Id. at 4.
ORDER NO. 37042 2

The Company requested approval to update its residential development costs.Id. at 5. The
update to the residential development costs were based on the Company's current Construction&
Material Standards, which reflected the most recent revisions to the National Electrical Safety
Code, and average construction costs for 2025.Id. The Company proposed the following updates:
Residential Developments Present Proposed
Total Cost per Lot $ 3,849 $ 3,818
Less: Service Cost $ 516 $ 541
Developer Responsibility $ 3,333 $ 3 277
Developer Refundable Payment $ 2,545 $ 2,755
Builder Non-Refundable Payment $ 1,304 $ 1,063
Allowance $ 2,545 $ 2,755
Id.
The Company requested approval to remove "after the extension is completed" from
Schedule 51G.Id. Schedule 5 1 G states the following:
A Developer who pays the extension cost described in 4.b.1) may apply for a refund
annually for each permanent Customer connected within the development during the first
five years from the start of construction after the extension is completed.
Id. The Company felt removing "after the extension is completed" would clarify that developers
who pay for extension costs described in 4.b.1)can apply for a refund annually for each permanent
customer that is connected in the development in the first five years following the start of
construction. Id. Lastly, the Company indicated that it would send a letter to its developer and
builder customers who could be affected by the Company's proposed changes to Schedule 51.Id.
STAFF COMMENTS
After reviewing the Company's Application and supporting workpapers, and comparing
the Company's requested cost changes to the costs approved by the Commission in Order No.
36613, Staff recommended that the Commission: (1)approve the Company's proposed changes to
construction allowances and average costs in Schedule 51; (2) approve the Company's requested
change to Schedule 51G's language; and (3) approve the Company's proposed Schedule 51 tariff
as filed, with a May 15, 2026, effective date, or an effective date of the Commission's final Order
in this case, whichever occurs later. Staff Comments at 2.
ORDER NO. 37042 3

I. Construction Allowances.
Staff reviewed the Company's proposed updates for new residential, commercial, and
industrial customer services outlined in Table 1 of the Application. Id. at 2-3. Because Staff
believed the Company used the embedded-cost methodology approach and inputs previously
approved by the Commission, Staff recommended that the Commission approve the construction
allowance changes in Schedule 51.Id. at 3.
II. Average Costs.
To review the Company's proposed changes to average costs for primary circuit,secondary
circuit, service circuit, and transformer, Staff compared the Company's average costs proposed in
the Application to the average costs approved in Order No. 36613. Staff Comments at 3. As a
result, Staff calculated the difference between the Company's existing costs and proposed costs:
Table No. 2: Proposed Average Cost Changes
Costs lExisting Proposed jIncrease Rate
Overhead Primary Circuit
Fixed Cost $5,536 $5,952 7.51%
Variable Cost $11.20 $12.04 7.50%
Underground Primary Circuit
Fixed Cost $2,583 $2,754 6.62%
Variable Cost $13.55 $14.31 5.61%
Underground Secondary Circuit
Fixed Cost $647 $688 6.34%
Variable Cost $12.75 $13.18 3.37%
Overhead Secondary Circuit
Fixed Cost $2,279 $2,466 8.21%
Overhead Service Circuit $5.06 $5.56 9.88%
Underground Service Circuit $10.29 $10.78 4.76%
Overhead Transformer $5,308 $5,222 -1.62%
Padmount Transformer $10,003 $9,134 -8.69%
Id. at 4.
ORDER NO. 37042 4

The Company's overhead costs increased by 20.20%. Id. Specifically, labor overhead
increased by 15%.Id. Staff believed that the higher labor overhead costs contributed to the average
cost increase. Id. at 4-5. The Company's vehicle costs also increased by 21.01%. Id. at 5.
Specifically, repair costs for the Company's double bucket trucks increased by 69.30% and repair
costs for its tandem diggers increased by 53.30%.Id. Based on Staff's calculations,the Company's
fuel usage increased by 22.85% and resulted in the Company's fuel costs rising by 26.03%. Id.
Staff believed that the Company's higher vehicle costs and fuel usage contributed to the average
cost increase.Id.
III. Residential Developments.
After reviewing the Company's proposed cost changes to residential development, Staff
believed that the developer responsibility cost decreased by 1.68%, as detailed in the following
table:
Table No. 3: Proposed Residential Development Cost Changes
Residential Development Existing Proposed Increase Rate
Total Cost per Lot $3,849 $3,818
Less: Service Cost $516 $541 4.84%
Developer Responsibility $3,333 $3,277 -1.68%
Developer Refundable Payment $2,545 $2,755
Builder Non-Refundable Payment $1,304 $1,063
Allowance $2,545 $2,755
Id. at 5. Staff believed the decrease in developer responsibility costs were reasonable because even
though overhead and tool costs increased by 15.9% and 17.4%, respectively, material costs
decreased by 8.7%, and those costs make up most of the expenses for developer responsibility.Id.
IV. Administrative Changes & Customer Notice.
Staff agreed that removing "after the extension is completed" from Schedule 51 G would
help clarify that the start of construction is when the five-year look back period begins. Id. Staff
also believed that the Company's Customer notice met the requirements of Rule 125 of the Idaho
ORDER NO. 37042 5

Administrative Procedures Act 31.01.01 and provided a reasonable amount of time for the public
to file comments before the Commission's set deadline. Staff Comments at 5.
COMMISSION FINDINGS AND DECISION
The Commission has jurisdiction over the Company's Filing and the issues in this case
under Title 61 of the Idaho Code including, Idaho Code §§ 61-501, -502, and -503. The
Commission is empowered to investigate rates, charges,rules,regulations,practices, and contracts
of all public utilities and to determine whether they are just, reasonable, preferential,
discriminatory, or in violation of any provisions of law, and to fix the same by order.Idaho Code
§§ 61-501, -502, and-503.
The Commission has reviewed the record in this case. Based on our review,we find it fair,
just, and reasonable to: (1) approve the Company's proposed changes to construction allowances
and average costs in Schedule 51; (2)approve the Company's requested change to Schedule 51G's
language; and (3) approve the Company's proposed Schedule 51 tariff as filed, with a May 15,
2026 effective date.
The Commission finds that the Company used the embedded-cost methodology approach
and inputs previously approved by the Commission. Further, the Commission finds that the
Company's higher vehicle costs and fuel usage contributed to the average cost increase in Schedule
51. The Commission finds that because the Company's costs for material decreased, which make
up most of the expenses for developer responsibility costs, it is reasonable that the developer
responsibility costs decreased in Schedule 51. The Commission finds that removing "after the
extension is completed" from Schedule 51 G will clarify that the start of construction is when the
five-year look back period begins under Schedule 51. Id. Lastly, the Commission finds that the
Company's Customer notice meets the requirements of Rule 125 of the Idaho Administrative
Procedures Act 31.01.01 and provided a reasonable amount of time for the public to file comments.
ORDER
IT IS HEREBY ORDERED that the Application to update costs for Schedule 51 and
remove "after the extension is completed" from Schedule 51 G is approved as filed.
THIS IS A FINAL ORDER. Any person interested in this Order may petition for
reconsideration within 21 days of the service date of this Order regarding any matter decided in
ORDER NO. 37042 6

this Order.Within seven days after any person has petitioned for reconsideration, any other person
may cross-petition for reconsideration.Idaho Code § 61-626.
DONE by Order of the Idaho Public Utilities Commission at Boise, Idaho this 15"' day of
May 2026.
G
EDWARD LODGE, PR „ DENT
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JO R. HAMMOND JR., COMMISSIONER
DAYN HAKDIE, COMMISSIONER
ATTEST:
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Monic 13anl'oWmchez
Commission Secretary
I:\Legal\ELECTRICV+VU-E-26-02_Sch 51\orders\AVUE2602_FO_kr.docx
ORDER NO. 37042 7