Exhibit 99.1

WILLIAM LYON HOMES REPORTS FOURTH QUARTER AND FULL YEAR 2014 RESULTS

NEWPORT BEACH, CA—February 20, 2015—William Lyon Homes (NYSE: WLH), a leading homebuilder in the Western U.S., announced results for its 2014 fourth quarter and full year ended December 31, 2014.

2014 Fourth Quarter Highlights (Comparison to 2013 Fourth Quarter)

2014 Full Year Highlights (Comparison to 2013 Full Year)

“We are extremely pleased with our fourth quarter results, which mark our highest quarterly home sales revenue and deliveries since the fourth quarter of 2007,” said William H. Lyon, Chief Executive Officer. “Home sales revenue increased by 93% to $352.5 million and deliveries increased by 83% to 717 units, both of which exceeded our expectations. We continue to improve our year-over-year performance across a number of key operational and financial metrics including net new home orders, the dollar value of orders and backlog, and community count. In addition, we generated net income of $18.0 million, or $0.52 per diluted share for the fourth quarter.” Mr. Lyon continued, “2014 was a transformational year for William Lyon Homes as we expanded our geographic footprint with the acquisition of Polygon Northwest Homes, and through our Coastal California infill portfolio acquisition. We are well positioned to capitalize on the continued housing recovery.”

Matthew R. Zaist, President and Chief Operating Officer stated, “In 2014, we delivered strong execution on our growth strategy, generating net income of $44.6 million, while also increasing our community count to 56 locations and delivering over 1,750 homes.” Mr. Zaist continued, “As we turn our attention to the execution of our 2015 objectives, we are focused on opening new communities and driving meaningful increases in orders, deliveries, revenue and net income.”

Operating Results

Home sales revenue for the fourth quarter of 2014 nearly doubled to $352.5 million, as compared to $182.9 million in the year-ago period. Our performance was driven by an 83% increase in the number of deliveries to 717 homes and a 5% increase in the average sales price of homes delivered to $491,600 in the quarter, compared to 391 homes delivered and a $467,700 average sales price, respectively, in the year-ago period. The fourth quarter of 2014 represented our first full quarter including the operating results of our recently acquired Washington and Oregon divisions, which generated revenues during the quarter of $93.4 million, consisting of 261 homes delivered at an average sales price of $357,900.

The dollar value of our orders for the fourth quarter of 2014 was $216.8 million, an increase of 27%, from $170.5 million in the year-ago period. Net new home orders for the quarter were 467, up 60% from 292 in the fourth quarter of 2013. The overall increase in net new home orders was driven by an increase in community count to 55 average sales locations, from 31 in the year-ago period and consistent absorption of 0.7 sales per project per week in both periods. We ended the year with 56 active selling communities, a 75% increase as compared to 32 active selling communities at the end of 2013.

The dollar value of homes in backlog was $260.1 million as of December 31, 2014, an increase of 30% compared to $199.5 million as of December 31, 2013. The increase was driven by a 30% increase in units in backlog to 478 from 368 in the year-ago period and a relatively stable average sales price of homes in backlog of $544,200, as compared to $542,200 in the year-ago period.

Homebuilding gross margins for the fourth quarter of 2014 were 19.0%. In conjunction with the adoption of purchase accounting related to the Polygon acquisition, GAAP margins were impacted by 170 basis points during the quarter. Adjusted homebuilding gross margin percentage was 23.5% during the fourth quarter of 2014.

SG&A expense during the fourth quarter of 2014 was 10.4% of homebuilding revenue, an improvement of 130 basis points from 11.7% in the year-ago quarter. Breaking down the components of SG&A, sales and marketing expense was 5.1% of homebuilding revenue during the quarter, compared to 4.7% in the year-ago quarter, driven primarily by higher advertising costs and outside broker commissions. General administrative expenses decreased to 5.3% of homebuilding revenue, compared to 7.0% in the year-ago quarter, as we continued to leverage off of a larger operating platform with a lower relative cost structure.

Balance Sheet Update

At year end, cash, cash equivalents and restricted cash totaled $53.3 million, real estate inventories totaled $1.4 billion, total debt was $940.1 million and total equity was almost $600.0 million. During the fourth quarter we executed a registered public offering of tangible equity units which generated net proceeds of approximately $111.4 million to the Company, which we used to pay off in full the senior unsecured bridge loan facility that we had entered into in connection with the closing of the Polygon Northwest Homes acquisition. At December 31, 2014, net debt to net book capitalization was 59.8%, and total debt to total book capitalization was 61.2%.

Conference Call

The Company will host a conference call to discuss these results today, Friday, February 20, 2015 at 9:00 a.m. Pacific Time. The call will be available via both the telephone at (877) 280-4961 or (857) 244-7314, passcode #27184096, or through the Company’s website at www.lyonhomes.com in the Investor Relations section of the site. A replay of the call will be available through March 5, 2015 by dialing (888) 286-8010 or (617) 801-6888, passcode #50466741. A webcast replay of the call will also be available on the Company’s website approximately two hours after the broadcast.

About William Lyon Homes

William Lyon Homes is one of the largest Western U.S. regional homebuilders. Headquartered in Newport Beach, California, the Company is primarily engaged in the design, construction, marketing and sale of single-family detached and attached homes in California, Arizona, Nevada, Colorado, Washington and Oregon. Its core markets include Orange County, Los Angeles, San Diego, the San Francisco Bay Area, Phoenix, Las Vegas, Denver, Seattle and Portland. The Company has a distinguished legacy of more than 59 years of homebuilding operations, over which time it has sold in excess of 93,000 homes. The Company markets and sells its homes under the William Lyon Homes brand in all of its markets except for Colorado, where the Company operates under the Village Homes brand, and Washington and Oregon, where the Company operates under the Polygon Northwest brand.

Financial data included herein includes the Washington and Oregon operations from August 12, 2014 (date of the Polygon Northwest Homes acquisition) through December 31, 2014. There were no operations in the Company’s Washington and Oregon divisions for the three or twelve months ended December 31, 2013; therefore, period-over-period comparisons for Washington and Oregon are not meaningful (“N/M”) as indicated in the comparative tables in the schedules attached to this release.

Certain statements contained in this release and the accompanying comments during our conference call that are not historical information contain forward-looking statements, including, but not limited to, statements related to: market and industry trends, the anticipated financial and operating results from execution of the Company’s growth strategy and focus on markets in the Western United States, the continued housing market recovery, expected community count growth, anticipated operating results for the first quarter of 2015 and the spring selling season, expected SG&A percentage, and the anticipated benefits to be realized from the consummation of the Polygon Northwest acquisition. The forward-looking statements involve risks and uncertainties and actual results may differ materially from those projected or implied. The Company makes no commitment, and disclaims any duty, to update or revise any forward-looking statements to reflect future events or changes in these expectations. Further, certain forward-looking statements are based on assumptions of future events which may not prove to be accurate. Factors that may impact such forward-looking statements include, among others: our ability to realize the anticipated benefits from the acquisition of Polygon Northwest; our ability to integrate successfully the Polygon Northwest operation with our existing operations; any adverse effect on our business operations, or those of Polygon Northwest, following consummation of the acquisition; worsening in general economic conditions either nationally or in regions in which we operate; conditions in our newly entered markets and newly acquired operations; worsening in markets for residential housing; decline in real estate values resulting in impairment of our real estate assets; volatility in the banking industry and credit markets; uncertainties in the capital and securities markets; terrorism or other hostilities involving the United States; whether an ownership change occurred that could, under certain circumstances, have resulted in the limitation of our ability to offset prior years’ taxable income with net operating losses; changes in mortgage and other interest rates; conditions in the capital, credit and financial markets, including mortgage lending standards and the availability of mortgage financing; changes in generally accepted accounting principles or interpretations of those

principles; changes in prices of homebuilding materials; the availability of labor and homebuilding materials; adverse weather conditions; competition for home sales from other sellers of new and resale homes; cancellations and our ability to realize our backlog; the occurrence of events such as landslides, soil subsidence and earthquakes that are uninsurable, not economically insurable or not subject to effective indemnification agreements; changes in governmental laws and regulations; our financial leverage and level of indebtedness and any inability to comply with financial and other covenants under our debt instruments; whether we are able to refinance the outstanding balances of our debt obligations at their maturity; anticipated tax refunds; limitations on our ability to utilize our tax attributes; limitations on our ability to reverse any remaining portion of our valuation allowance with respect to our deferred tax assets; the timing of receipt of regulatory approvals and the opening of projects; the impact of construction defect, product liability and home warranty claims, including the adequacy of self-insurance accruals, and the applicability and sufficiency of our insurance coverage; the availability and cost of land for future development; and additional factors discussed under the sections captioned “Risk Factors” included in our annual and quarterly reports filed with the Securities and Exchange Commission. The foregoing list is not exhaustive. New risk factors may emerge from time to time and it is not possible for management to predict all such risk factors or to assess the impact of such risk factors on our business.

Investor/Media Contacts:

Larry Clark

Financial Profiles, Inc.

(310) 622-8223

WLH@finprofiles.com

Lisa Mueller

Financial Profiles, Inc.

(310) 622-8231

WLH@finprofiles.com

WILLIAM LYON HOMES

CONSOLIDATED STATEMENTS OF OPERATIONS

(in thousands except number of shares and per share data)

(unaudited)

WILLIAM LYON HOMES

CONSOLIDATED STATEMENTS OF OPERATIONS

(in thousands except number of shares and per share data)

WILLIAM LYON HOMES

CONSOLIDATED BALANCE SHEETS

(in thousands, except number of shares and par value per share)

WILLIAM LYON HOMES

SELECTED FINANCIAL AND OPERATING INFORMATION

(unaudited)

WILLIAM LYON HOMES

SELECTED FINANCIAL AND OPERATING INFORMATION

(unaudited)

WILLIAM LYON HOMES

SELECTED FINANCIAL AND OPERATING INFORMATION

(unaudited)

WILLIAM LYON HOMES

SUPPLEMENTAL FINANCIAL INFORMATION

(unaudited)

Balance Sheet Data

WILLIAM LYON HOMES

SUPPLEMENTAL FINANCIAL INFORMATION

(unaudited)