Resilient Cash Generation, Enduring Value,

Three Powerful Businesses

March 18, 2009

2

Forward-Looking Statements and Non-GAAP Measures

This presentation contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Forward-looking statements present our current forecasts and estimates of future events. These forward-looking statements are subject to risks, uncertainties and other factors that could cause actual results to differ materially from those projected in these statements. Such factors include, without limitation: economic and political conditions, including new legislation or other governmental actions; levels of residential and commercial construction activity; competitive factors; pricing pressures; weather conditions; our level of indebtedness; industry and economic conditions that adversely affect the market and operating conditions of our customers, suppliers or lenders; availability and cost of energy and materials; availability and cost of credit; interest rate movements; issues involving implementation of acquisitions, divestitures and joint ventures; our ability to use our net operating loss carryforwards; achievement of expected synergies, cost reductions and/or productivity improvements; issues involving implementation of new business systems; foreign exchange fluctuations; the success of research and development activities; difficulties in managing production capacity; labor disputes; and factors detailed from time to time in the Company’s Securities and Exchange Commission filings. The information in this presentation speaks as of the date March 18, 2009 and is subject to change. The Company does not undertake any duty to update or revise forward-looking statements. Any distribution of this presentation after that date is not intended and will not be construed as updating or confirming such information.

Additional Company information is available on the Owens Corning Web site: www.owenscorning.com.

Certain data included within this presentation contains "non-GAAP financial measures" as defined by the Securities and Exchange Commission. A reconciliation of these non-GAAP financial measures to their most directly comparable financial measures calculated and presented in accordance with generally accepted accounting principles can be found in our Current Report on Form 8-K filed with the Securities and Exchange Commission on February 18, 2009.

3

Owens Corning’s Key Themes

• Delivered strong operating results in 2008– $290 million Adjusted EBIT, D&A of $331 million ($621 million Adjusted EBITDA)– Generated $34 million positive free cash flow*– Significantly better performance vs. last recession (2002)

• 2002**: 1.7 million housing starts – Adj. EBIT $300 million and D&A of $205 million• 2008: 900,000 housing starts – Adj. EBIT $290 million and D&A of $331 million

– Completed successful integration of Composites acquisition

• Aggressively managing the business through the down cycle– Expect to have positive free cash flow in 2009– Positioning the company for strong post-recession performance

• Three valuable business franchises: Composites, Insulation, Roofing and Asphalt

– All have leading positions in their respective markets– Capable of combined through-the-cycle EBITDA of $1 billion-plus performance – Provides excellent diversification in end-use markets, with global presence

Resilient cash generation and enduring value built on three powerful businesses

* Change in net debt plus cash used for stock repurchases* * 2002 financial information provided as filed in 2004 10-K

4

Owens Corning At A Glance

• Founded in 1938, an industry leader in glass fiber insulation, roofing and asphalt and glass fiber reinforcements

• 2008 sales: $5.8 billion

• 17,000 employees in 26 countries

• Senior debt ratings: BBB- and Ba1

• FORTUNE 500 company for 54 consecutive years

• Residential Insulation• Commercial & Industrial Insulation• Manufactured Stone Veneer• Residential Shingles• Roofing Asphalts

• Composites

Global Leader

Leading North AmericanMarket Positions

THE PINK PANTHER™ © 1964-2009 Metro-Goldwyn-Mayer Studios Inc. All Rights Reserved.The color PINK is a registered trademark of Owens Corning. © 2009 Owens Corning.

5

Strong Performance in 2008

• Exceeded our initial guidance and targets: Adjusted EBIT of $290 million– Composites

• Integrated acquisition• Maintained share and generated synergies of $50 million• Delivered 10% EBIT margin for the first nine months of 2008

– Roofing and Asphalt• Delivered record earnings• Achieved gains through streamlined asset base, manufacturing efficiencies and pricing

actions that outpaced inflation– Insulation

• Delivered positive earnings in historically weak housing market• Took aggressive actions to reduce production capacity and align cost structure to market

demand

• Delivered $100 million in cost savings in advance of the global economic downturn

– Reduced active number of employees by 2,300 since end of 2007

• Reduced precious metal lease exposure by $300 million through operational improvements

– Acquired lease portfolio expected to be reduced to zero by March 2009– Further operational improvements will be delivered in the next 12-18 months

6

Strong Liquidity within Existing Facilities; Comfortable Position with Respect to Covenants & Refinancing

• Plenty of “head-room” with respect to covenants for senior revolving credit facility

• Ample liquidity to meet financial obligations and support globalgrowth strategy

– $615 million available in senior revolving credit facility with $236 million cash on hand, at year-end 2008

– Cash coupled with future cash flows and other sources of liquidity expected to provide sufficient liquidity to meet cash requirements

– No significant debt maturities until Q4 2011

Leverage Ratio 43.5% *As of Dec. 31, 2008

65%Maximum Allowed

Interest Expense Coverage Ratio

4.9x* for 2008 2.0x Minimum Required

* Company calculations for compliance certificate

Three Powerful Businesses,Three Valuable Franchises

Composites

Roofing and Asphalt

Insulating Systems

8

An engineered material system…

…resulting in unique attributes replacing traditional materials

+ Other Materials• Resins• Additives• Filler

Reinforcements

Light WeightDurable Non-ConductiveUp to 50% Lighter

Than Steel Safety

This is a “Composite”

Source: Owens Corning

High StrengthNon-CorrosiveLonger Blades

Glass 95%* Other

9

CompositesGlobal Leadership in a high-growth industryCompositesGlobal Leadership in a high-growth industry

• High-growth markets driving glass fiber demand 1.5 to 2x global GDP growth

• Global asset base serves as a platform for growth to meet the needs of our customers

• Global product offerings that sustain a premium price in many markets

• Resources to deliver innovation and create new opportunities for growth

• Will deliver sustained EBIT margin performance in the low teens

10

0

1,000

2,000

3,000

4,000

1981 1986 1991 1996 2001 2006

Dem

and (kt)

+7% CAGR

-2%

+4% CAGR

-7%

+5% CAGR

Growth Drivers:

Key Innovation:

Shingles

Pipe

Pipe

RTP/Lam Shingle

RTP/Lam Shingle/China

Wind Blades

Asia

ROW

0%

-9%

Anticipated Downturns

• Previous downturns less than 24 mos., followed by mid-single digit growth• Application innovation & emerging markets drive growth

CompositesGlobal Glass Fiber Demand History

Long term growth of 5%+ = 1.5 – 2x global GDP

Source: Industry publications and Owens Corning estimates

11Source: Management estimates

Innovation

Manufacturing Cost: • Advantex • Best practicesSupply Chain:

• Product rationalization• Reducing shipping costs

Operating Expenses: • Eliminating redundancies

50%

20%

30%

CompositesAcquisition synergies

Accelerating acquisition synergies to achieve target one-year early

5075

100 100

0

20

40

60

80

100

120

2008 2009 2010 2011

$MM

+

12

10%14%

3%

9% 10% 10%8% 7%

9% 9%

4%

10%

0%

3%

6%

9%

12%

15%

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

L-T Avg

Marg

in**

Composites EBIT Margin

10 year average (9%)

Acquisition of Vetrotex

** 10-year average + acquisition synergies

We will deliver low-teen EBIT margins

*

EB

IT M

argi

n

Source: Company SEC Filings and management estimates, comparability may differ over time

* 4% increase in EBIT margin resulting from acquisition synergies ($100MM on $2.5B revenue)

13

Hip & Ridge Shingles

VentSure® Ventilation Products

Owens Corning Felt Underlayment Products

Owens Corning Shingles

Owens Corning Starter Shingle ProductsWeatherLock® Self-Sealing Ice & Water Barrier ProductsRapidFlowTM Gutter Drainage Protectionraft-R-mate® Attic Rafter VentUndereave Ventilation Products

AttiCat® Expanding Blown-In Pink FiberglasTM Insulation

Hip & Ridge Shingles

VentSure® Ventilation Products

Owens Corning Felt Underlayment Products

Owens Corning Shingles

Owens Corning Starter Shingle Products

Roofing: “Top of the House” Solutions

14

70s 80s 90s Current

FRY/OC OC OC OCGAF GAF GAF GAF/ELK ELK ELK ELK

CERTAINTEED CERTAINTEED CERTAINTEED CERTAINTEEDTAMKO TAMKO TAMKO TAMKO

CELOTEX CELOTEXMANVILLE MANVILLE

IKO IKO IKO IKOGLOBE GLOBE

BIRD BIRDATLAS ATLAS ATLAS ATLAS

GEORGIA PACIFIC GEORGIA PACIFIC GEORGIA PACIFICFLINTKOTE FLINTKOTE GENSTAR (Flintkote)

PABCO PABCO PABCO PABCOMALARKEY MALARKEY MALARKEY MALARKEY

LUNDAY THAGARD LUNDAY THAGARDBIG CHIEF

BEARREGIONAL1REGIONAL2REGIONAL3

90% 16 13 9 4

Roofing and AsphaltU.S. Industry Consolidation

A favorable industry structure for the future

Total 21 16 11 8

Source: Management estimates and industry sources and publications

15

102

27

5

103

30

11

104

30

3

106

33

5

107

33

3

103

31

2

108

32

3

110

32

2

110

37

7

113

40

8

114

41

18

109

36

9

99

27

3

92

19

23

92

129

101

24

5

107

34

5

109

36

5

111

36

5

0

170

'95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06 '07 '08 '09P '10E '11E '12E '13E

Re-roof New Constr Major Storms

New Const. (19%)Carry-over storm

demandTex. & Tenn.hail storms

New Const. (5%)No major storms

New Construction (25%)Low storm demand

MM Sqs

Total Mkt 134 144 137 144 143 136 143 145 154 161 173 154 129 133 113 130 146 150 152% Change 2 7 -5 5 -1 -5 5 1 6 5 7 -11 -16 3 -15 15 12 3 1Laminates 27 37 42 49 56 59 67 76 87 100 111 103 90 93 79 95 111 119 125% Lams 20 26 31 34 39 43 47 52 56 62 64 67 70 70 70 73 76 79 82

New Construction (31%) Hvy storm demand

Carolina hurricanes

Florida, Gulf Coast hurricanes

Roofing and Asphalt U. S. Asphalt Shingle Market Demand

Source: ARMA data, Moody’s Economy.com and Owens Corning management estimates

16

Roofing and AsphaltDelivering Sustained Margin PerformanceRoofing and AsphaltDelivering Sustained Margin Performance

• Enduring improvements to our cost position– Sold underperforming assets– Redesigned the shingle for significantly lower cost– Improved energy efficiency and manufacturing productivity

• Effective price discipline throughout 2008– Price increases offset asphalt inflation by end of Q3– Margins increased in Q4

• Mix improvement to enhance average margin– Increased sales of premium Duration shingles– Greater focus on roofing accessories

• Double-digit EBIT margins are sustainable– Favorable industry structure– OC margins have now matched and exceeded competitors’ levels*– Asphalt prices remain higher than historic averages

* Management estimates

17

Our Insulating Products

• Residential Insulating Batt – used in wall cavities of newly constructed and existing homes

• Foam Insulation – used in above- and below-grade construction applications

• Flexible Duct Media – insulated duct used in new and existing homes as a more energy-efficient HVAC solution than metal ducts

• Metal Building Insulation – insulation used in commercial and industrial metal buildings

• Commercial and Industrial Pipe Insulation – fiberglass insulated pipe used in hot and cold industrial applications

18

0.50

1.00

1.50

2.00

2.50

'85 '87 '89 '91 '93 '95 '97 '99 '01 '03 '05 '07

Sta

rts

(mil)

0%

5%

10%

15%

20%

25%

EBIT

Mar

gin

%

Starts (single, multi, and mfg housing) EBIT %

Insulation EBIT Margin

• 20% EBIT margins demonstrated during periods of strong housing demand • 15% EBIT average over 24-year period

24 yr. avg. EBIT margin

Source: Management estimates, company filings and U.S. Census Bureau. Comparability may differ over time.

19

InsulationA proven long-term franchiseInsulationA proven long-term franchise

• The leading market position in North America residential and commercial and industrial fiberglass insulation

– Three producers represent about 80% of market

• Positive demographics and energy-efficiency policy will drive market recovery

• Our customer and channel diversity provides us an advantage, in all market conditions

• Energy efficiency and U.S. stimulus will increase demand

– Buildings are #1 user of energy in U.S.

– Stricter building codes will drive improved efficiency and demand

– Nearly 80 million homes in U.S. under-insulated

Source: Management estimates

20

2009 American Recovery and Reinvestment Act: Key Energy Efficiency & Green Energy Provisions

• Existing Home Tax Credit– 30% credit up to $1,500– Requires compliance with IECC 2009 codes

• Low Income Weatherization– $5 billion through October 1, 2010– Expands eligibility to 200% of poverty level

• Wind Energy Development– Extended production tax credit– Investment tax credit introduced

– Credits can be redeemed at U.S. Treasury for cash

Aggressive marketing campaign

Increased training for installers

Coordinated promotions with retailers

Develop public/private state programs

Engage 900 Community Agencies

Promote attic insulation as first thing to do

Introduce wall solution

Continued technological innovation

Maintain leading market share

Continue to develop specialty applications

Provision Owens Corning Actions

Owens Corning is positioned to benefit from the provisions of this legislation

21

Owens Corning through-the-cycle EBITDAOwens Corning’s core franchises are capable of through-the-cycle EBITDA of $1B+

Assumes return to projected normal / mid-cycle demand environment

Source: Management estimates

Composites

EBITMargin Range

Insulation

Roofing

• Exposure to higher growth markets: 1.5 –2.0x global GDP growth

• Market consolidation and product innovation leading to double-digit margins

• Synergies from acquisition drive EBIT margins to low teens

Revenue DescriptionEBIT (MM)

Normalized

• Long-term EBIT margins average 15%• Limited new industry capacity and significant

barriers to entry• Top 3 producers supply about 80% of North

America fiberglass demand• “Green” initiatives and stimulus plan will improve

demand

• Improved industry structure – Top 4 producers supply about 90% of demand

• About 75% of demand from repair & remodel• Sustainable business improvements

– Manufacturing gains– Improved product mix

Total

$160200240

$2.0B =

$240300400

$2.0B =

$2.5B$250300350

=

$6.5B $650 - $990

8%10%12%

12%15%20%

10%12%14%

+ $350 - $400 = $1.0B to 1.4BOther (1) EBITDA

(1) Includes Depreciation & Amortization, Other Building Materials & Services and Corporate Expenses

x

x

x

22

In Summary: Owens Corning’s Business Portfolio

• Three valuable business franchises with market-leading positions in their respective industries

• All three franchises are well positioned for strong earnings growth when the business cycle turns up

• OC is actively driving, and is positioned to benefit from, world-wide energy policy initiatives

• OC has a balanced business portfolio with limited exposure to any one market and is capable of generating cash in today’s severe market conditions

Capable of through-the-cycle EBITDA of $1 billion +

23

Owens Corning’s 2009 Market Outlook

• Free cash flow positive

• Aggressive management of costs, headcount, capacity and capital

• Favorable momentum in roofing business continues

• Prolonged weakness in insulation business

• Weak start for Composites, with improvement through the year