On April 18, 2019, the Company’s stockholders approved the Owens Corning 2019 Stock Plan (the “2019 Stock Plan”) which authorizes grants of stock options, stock appreciation rights, restricted stock awards, restricted stock units, bonus stock awards and performance stock awards. At March 31, 2020, the number of shares remaining available under the 2019 Stock Plan for all stock awards was approximately 3.5 million.

Stock-based compensation expense included in Marketing and administrative expenses in the accompanying Consolidated Statements of Earnings (Loss) is as follows (in millions):

The Company has granted stock options under its stockholder approved stock plans. The Company calculates a weighted-average grant-date fair value using a Black-Scholes valuation model for options granted. Compensation expense for options is measured based on the fair market value of the option on the date of grant, and is recognized on a straight-line basis over a four year vesting period. In general, the exercise price of each option awarded was equal to the closing market price of the Company’s common stock on the date of grant and an option’s maximum term is 10 years. The volatility assumption was based on a benchmark study of our peers prior to 2014. Starting with the options granted in 2014, the volatility was based on the Company’s historic volatility.

The Company has not granted stock options since the year ended December 31, 2014. As of March 31, 2020, there was no unrecognized compensation cost related to stock options and the range of exercise prices on outstanding stock options was $33.73 - $42.16.


		Weighted-Average
	Number of Options	Exercise Price		Remaining Contractual Life (in years)	Intrinsic Value (in millions)
Outstanding, December 31, 2019	414,800	$	37.79	3.06	$	11

Exercised	(9,675)	33.95


Outstanding, March 31, 2020	405,125	$	37.88	2.89	$	1
Exercisable, March 31, 2020	405,125	$	37.88	2.89	$	1

The Company has granted restricted stock awards and restricted stock units (collectively referred to as “RSUs”) under its stockholder approved stock plans. Compensation expense for RSUs is measured based on the closing market price of the stock at date of grant and is recognized on a straight-line basis over the vesting period, which is typically three or four years. The Stock Plan allows alternate vesting schedules for death, disability, and retirement. The weighted average grant date fair value of RSUs granted in 2020 was $63.65.



	Number of RSUs	Weighted-Average Fair Value
Balance at December 31, 2019	1,515,706	$	51.70
Granted	382,270	63.71
Vested	(328,663)	57.74
Forfeited	(12,525)	63.33
Balance at March 31, 2020	1,556,788	$	53.24

As of March 31, 2020, there was $44 million of total unrecognized compensation cost related to restricted stock. That cost is expected to be recognized over a weighted-average period of 2.42 years. The total grant date fair value of shares vested during the three months ended March 31, 2020 and 2019 was $19 million and $18 million, respectively.

The Company has granted performance stock awards and performance stock units (collectively referred to as “PSUs”) as a part of its long-term incentive plan. All outstanding performance grants will fully settle in stock. The amount of stock ultimately distributed from all performance shares is contingent on meeting internal company-based metrics or an external-based stock performance metric.

The internal company-based metrics are based on various Company metrics and typically vest over a three-year period. The amount of stock distributed will vary from 0% to 300% of PSUs awarded depending on each award's design and performance versus the internal Company-based metrics.

The initial fair value for all internal Company-based metric PSUs assumes that the performance goals will be achieved and is based on the grant date stock price. This assumption is monitored quarterly and if it becomes probable that such goals will not be achieved or will be exceeded, compensation expense recognized will be adjusted and previous surplus compensation expense recognized will be reversed or additional expense will be recognized. The expected term represents the period from the grant date to the end of the vesting period. Pro-rata vesting may be utilized in the case of death, disability or approved retirement and awards, if earned, will be paid at the end of the vesting period.

The external-based metrics vest after a three-year period. Outstanding grants issued in or after 2018 are based on the Company's total stockholder return relative to the performance of the Dow Jones U.S. Construction & Materials Index. The amount of stock distributed will vary from 0% to 200% of PSUs awarded depending on the relative stockholder return performance. The fair value of external-based metric PSUs has been estimated at the grant date using a Monte Carlo simulation that uses various assumptions.

The risk-free interest rate was based on zero coupon United States Treasury bills at the grant date. The expected term represents the period from the grant date to the end of the three-year performance period.

As of March 31, 2020, there was $17 million total unrecognized compensation cost related to PSUs. That cost is expected to be recognized over a weighted-average period of 2.16 years. The total grant date fair value of shares vested during the three months ended March 31, 2020 was $1 million.



	Number of PSUs	Weighted-Average Grant-Date Fair Value
Balance at December 31, 2019	312,725	$	69.23
Granted	154,078	64.28
Vested	(9,558)	84.59
Forfeited	(1,240)	73.16
Balance at March 31, 2020	456,005	$	69.94

The Owens Corning Employee Stock Purchase Plan (ESPP) is a tax-qualified plan under Section 423 of the Internal Revenue Code. The purchase price of shares purchased under the ESPP is equal to 85% of the lower of the fair market value of shares of Owens Corning common stock at the beginning or ending of the offering period, which is a six-month period ending on May 31 and November 30 of each year. At the approval date, 2.0 million shares were available for purchase under the ESPP. As of March 31, 2020, 0.3 million shares remain available for purchase. On April 16, 2020, the Company's stockholders approved the Amended and Restated Owens Corning Employee Stock Purchase Plan which increased the number of shares available for issuance under the plan by 4.2 million shares.

During the three months ended March 31, 2020 and 2019, the Company recognized expense of $1 million related to the Company's ESPP. As of March 31, 2020, there was $1 million of total unrecognized compensation cost related to the ESPP.