Use of Estimates—Preparation of these consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions. These estimates and the underlying assumptions affect the amounts of assets and liabilities reported, disclosures about contingent assets and liabilities and reported amounts of revenue and expenses. Such estimates include the valuation of accounts receivable, inventories, goodwill, intangibles and other long-lived assets, pension and other postretirement obligations and asset retirement obligations. Estimates also include revenue earned on contracts and costs to complete contracts. Most of the Company’s paving and related services are performed under fixed unit-price contracts with state and local governmental entities. Management regularly evaluates its estimates and assumptions based on historical experience and other factors, including the current economic environment. Management adjusts such estimates and assumptions when circumstances dictate. As future events and their effects cannot be determined with precision, actual results can differ significantly from estimates made. Changes in estimates, including those resulting from continuing changes in the economic environment, are reflected in the Company’s consolidated financial statements when the change in estimate occurs.

Use of Estimates—The consolidated financial statements of the Company have been prepared in conformity with U.S. generally accepted accounting principles (“U.S. GAAP”), which require management to make estimates and assumptions that affect the reported amounts and disclosures in the consolidated financial statements. These estimates and the underlying assumptions affect the amounts of assets and liabilities reported, disclosures about contingent assets and liabilities and reported amounts of revenue and expenses. Such estimates include the valuation of accounts receivable, inventories, goodwill, intangible and other long-lived assets, pension and other postretirement obligations, asset retirement obligations and the redeemable noncontrolling interest. Estimates also include revenue earned and costs to complete open contracts. Management evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors, including the current economic environment. Management adjusts such estimates and assumptions when circumstances dictate. As future events and their effects cannot be determined with precision, actual results could differ significantly from estimates made. Changes in estimates, including those resulting from continuing changes in the economic environment, will be reflected in the Company’s consolidated financial statements in the period in which the change in estimate occurs.

Accounts Receivable—Accounts receivable are stated at the amount management expects to collect from outstanding balances. Management provides for probable uncollectible amounts through a charge to earnings and a credit to a valuation allowance based on its assessment of the collectability of individual accounts. In establishing the allowance, management considers historical losses adjusted to take into account current market conditions and its customers’ financial condition, the amount of receivables in dispute, the current receivables aging and current payment terms. Balances that remain outstanding after reasonable collection efforts are exercised are written off through a charge to the valuation allowance.

The balances billed but not paid by customers, pursuant to retainage provisions included in contracts, will be due upon completion of the contracts.

Inventories—Inventories consist of stone removed from quarries and processed for future sale, cement, raw materials and finished concrete blocks. Inventories are valued at the lower of cost or market and are accounted for on a first-in first-out basis or an average cost basis. If items become obsolete or otherwise unusable or if quantities exceed what is projected to be sold within a reasonable period of time, they will be charged to costs of production in the period that the items are designated as obsolete or excess inventory. Stripping costs are costs of removing overburden and waste material to access aggregate materials and are recognized in cost of revenue in the same period as the revenue from the sale of the inventory.

Accrued Mining and Landfill Reclamation—The mining reclamation reserve and financial commitments for landfill closure and post-closure activities are based on management’s estimate of future cost requirements to reclaim property at both currently operating and closed sites. Estimates of these obligations have been developed based on management’s interpretation of current requirements and proposed regulatory changes and are intended to approximate fair value. Costs are estimated in current dollars, inflated until the expected time of payment, using an inflation rate of 2.5%, and then discounted back to present value using a credit-adjusted, risk-free rate on obligations of similar maturity, adjusted to reflect the Company’s credit rating. Changes in the credit-adjusted, risk-free rate do not change recorded liabilities. However, subsequent increases in the recognized obligations are measured using a current credit-adjusted, risk-free rate. Decreases in the recognized obligations are measured at the initial credit-adjusted, risk-free rate.

Significant changes in inflation rates or the amount or timing of future cost estimates typically result in both (1) a current adjustment to the recorded liability (and corresponding adjustment to the asset) and (2) a change in accretion of the liability and depreciation of the asset to be recorded prospectively over the remaining capacity of the unmined quarry or landfill.

Goodwill—Goodwill represents the purchase price paid in excess of the fair value of net tangible and intangible assets acquired. Goodwill recorded in connection with the Company’s acquisitions is primarily attributable to the expected profitability, assembled workforces of the acquired businesses and the synergies expected to arise after the Company’s acquisition of those businesses. Goodwill is not amortized, but is tested annually for impairment as of the first day of the fourth quarter and whenever events or circumstances indicate that goodwill may be impaired. The goodwill impairment test first uses a qualitative approach to determine whether it is more likely than not that the estimated fair value of a reporting unit is less than its carrying amount. If, as a result of the qualitative assessment, it is determined that an impairment is more likely than not, the two-step quantitative impairment test is then performed, otherwise further analysis is not required. The two-step impairment test first identifies potential goodwill impairment for each reporting unit and then, if necessary, measures the amount of the impairment loss. Goodwill is tested for impairment based on the Company’s operating companies, which management has determined to be the Company’s reporting units, which are one level below its segments in the Central and West regions. The East region is considered to be a single reporting unit.

Fair Value Measurements—Certain acquisitions made by the Company require the payment of contingent amounts of purchase consideration. These payments are contingent on specified operating results being achieved in periods subsequent to the acquisition and will only be made if earn-out thresholds are achieved. Contingent consideration obligations are measured at fair value each reporting period. Any adjustments to fair value are recognized in earnings in the period identified. Contingent consideration as of March 28, 2015 and December 27, 2014 was:

The fair value of the contingent consideration obligations approximated their carrying value as of March 28, 2015 and December 27, 2014. The fair values are based on unobservable, or Level 3, inputs, including projected probability-weighted cash payments and an 11.0% discount rate, which reflects a market discount rate. Changes in fair value may occur as a result of a change in actual or projected cash payments, the probability weightings applied by the Company to projected payments or a change in the discount rate. Significant increases or decreases in any of these inputs in isolation could result in a lower, or higher, fair value measurement. There were no material valuation adjustments to contingent consideration obligations in the three months ended March 28, 2015 or March 29, 2014.

Fair Value Measurements—The fair value accounting guidance establishes the following fair value hierarchy that prioritizes the inputs used to measure fair value:

Assets and liabilities measured at fair value in the consolidated balance sheets as of December 27, 2014 and December 28, 2013 are as follows:

Certain acquisitions made by the Company require the payment of additional consideration contingent upon the achievement of specified operating results, referred to as contingent consideration or earn-out obligations. These payments will not be made if earn-out thresholds are not achieved. Approximately $4.5 million and $1.9 million of the increase in contingent consideration obligations relate to the January 17, 2014 acquisition of Alleyton Resource Corporation, Colorado Gulf, LP and certain assets of Barten Shepard Investments, LP (collectively, “Alleyton”) and the October 3, 2014 acquisition of Concrete Supply of Topeka, Inc. and all of the membership interests of Penny’s Concrete and Ready Mix, L.L.C. and Builders Choice Concrete Company of Missouri, L.L.C. (collectively, “Concrete Supply”), respectively. No material earn-out payments have been made to date.

Summit Materials records contingent consideration at fair value on the acquisition date and then measures its fair value each reporting period. Any adjustments to fair value are recognized in earnings in the period identified. Management of the Company determines the appropriate policies and procedures to be used when determining the fair value of contingent consideration. Its fair values are based on unobservable inputs, or Level 3 assumptions, including projected probability-weighted cash payments and an 11.0% discount rate, which reflects the Company’s credit risk. Changes in fair value may occur as a result of a change in actual or projected cash payments, the probability weightings applied by the Company to projected payments or a change in the discount rate. Significant increases or decreases in any of these inputs in isolation could result in a significantly lower, or higher, fair value measurement. In 2014 and 2012, we recognized immaterial reductions to contingent consideration of $0.5 million and $0.4 million, respectively.

Initial Public Offering—Summit Inc. commenced operations on March 11, 2015 upon the pricing of the IPO of its Class A common stock. Summit Inc. raised $433.0 million, net of underwriting discounts, through the issuance of 25,555,555 shares of Class A common stock at a public offering price of $18.00 per share. Summit Inc. used the offering proceeds to purchase a number of newly-issued LP Units from Summit Holdings equal to the number of shares of Class A common stock issued to the public. Summit Inc. caused Summit Holdings to use these proceeds (i) to redeem $288.2 million in aggregate principal amount of outstanding 10 ¹⁄₂% Senior Notes due January 31, 2020 (“Senior Notes”) at a redemption price of 100% and an applicable premium thereon; (ii) to purchase 71,428,571 Class B Units of Continental Cement Company, L.L.C. (“Continental Cement”); (iii) to pay a one-time termination fee of $13.8 million primarily to affiliates of the Sponsors in connection with the termination of a transaction and management fee agreement; and (iv) for general corporate purposes. The $288.2 million redemption of Senior Notes was completed in the second quarter of 2015 at a redemption price equal to par plus an applicable premium of $38.2 million plus $5.2 million of accrued and unpaid interest.

Earnings per Share—The Company computes basic earnings per share attributable to stockholders by dividing income attributable to Summit Inc. by the weighted-average Class A common shares outstanding. Diluted earnings per share reflects the potential dilution beyond shares for basic earnings per share that could occur if securities or other contracts to issue common stock were exercised, converted into common stock, or resulted in the issuance of common stock that would have shared in the Company’s earnings. Since the Class B common shares have no economic value, they are not included in the weighted-average common share amount for basic or diluted earnings per share. In addition, as the Class A common shares are issued by Summit Inc., the earnings and equity interests of noncontrolling interests are not included in basic or diluted earnings per share.

New Accounting Standards — In April 2015, the FASB issued a new accounting standard to simplify the presentation of debt issuance costs. Accounting Standards Update (“ASU”) 2015-03, Simplifying the Presentation of Debt Issuance Costs, changes the presentation of debt issuance costs in financial statements. Under the ASU, an entity will present such costs in the balance sheet as a direct deduction from the related debt liability rather than as an asset. Amortization of the costs will continue to be reported as interest expense. The ASU is effective for public entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. The guidance will be applied retrospectively to all prior periods (i.e., the balance sheet for each period will be adjusted). Had the Company adopted this guidance as of the current period, both Other Assets (noncurrent) and Long-term Debt as of March 28, 2015 and December 27, 2014, would have decreased by $19.6 million and $17.2 million, respectively.

In April 2015, the FASB issued a new accounting standard, ASU 2015-04, Practical Expedient for the Measurement Date of an Employer’s Defined Benefit Obligation and Plan Assets, which gives an employer whose fiscal year-end does not coincide with a calendar month-end (e.g., an entity that has a 52- or 53-week fiscal year) the ability, as a practical expedient, to measure defined benefit retirement obligations and related plan assets as of the month-end that is closest to its fiscal year-end. The ASU is effective for public business entities for financial statements issued for fiscal years beginning after December 31, 2015, and interim periods within those fiscal years. Early application is permitted, and the ASU should be applied prospectively. The Company does not expect the adoption of the ASU to have a material effect on its financial position or results of operations.

In May 2014, the FASB issued a new accounting standard to improve and converge the financial reporting requirements for revenue from contracts with customers. ASU No. 2014-09, Revenue from Contracts with Customers, prescribes a five-step model for revenue recognition that will replace most existing revenue recognition guidance in U.S. GAAP. The ASU will supersede nearly all existing revenue recognition guidance under U.S. GAAP and provides that an entity recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This update also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments, and assets recognized from costs incurred to obtain or fulfill a contract. ASU No. 2014-09 allows for either full retrospective or modified retrospective adoption and will become effective for the Company in the first quarter of 2017. Early adoption is prohibited. Management is currently assessing the effect that the adoption of this standard will have on the consolidated financial statements.