Exhibit 5.1

[LETTERHEAD OF SMITH, GAMBRELL & RUSSELL, LLP]

June 9, 2017

Board of Directors

CalAtlantic Group, Inc.

1100 Wilson Boulevard, #2100

Arlington, Virginia 22209

Ladies and Gentlemen:

We have acted as Florida counsel to CalAtlantic Group, Inc., a Delaware corporation (the “Company”), and its affiliated Florida partnerships, Standard Pacific of South Florida, a Florida general partnership (“SPSF”), and Standard Pacific of Tampa, a Florida general partnership (“SPT”) (SPSF and SPT collectively herein referred to as the “Guarantors” and each individually sometimes called a “Guarantor”), in connection with the Company’s registration statement on Form S-3 (the “Registration Statement”) filed with the Securities and Exchange Commission (the “SEC”) pursuant to the Securities Act of 1933, as amended (the “Securities Act”), on or about the date hereof, relating to the Company’s issuance and sale of $350,000,000 principal amount of its 5.000% Senior Notes due 2027 (the “Securities”). The Securities are being issued under an indenture dated as of April 1, 1999 (the “Base Indenture”) between the Company and The Bank of New York Mellon Trust Company N.A. (as successor in interest to J.P. Morgan Trust Company N.A. and The First National Bank of Chicago), as trustee, as amended and supplemented by a First Supplemental Indenture dated as of April 13, 1999, a Second Supplemental Indenture dated as of September 5, 2000, a Third Supplemental Indenture dated as of December 28, 2001, a Fourth Supplemental Indenture dated as of March 4, 2003, a Fifth Supplemental Indenture dated as of May 12, 2003, a Sixth Supplemental Indenture dated as of September 23, 2003, a Seventh Supplemental Indenture dated as of March 11, 2004, an Eighth Supplemental Indenture dated as of March 11, 2004, a Ninth Supplemental Indenture dated as of August 1, 2005, a Tenth Supplemental Indenture dated as of August 1, 2005, an Eleventh Supplemental Indenture dated as of February 22, 2006, a Twelfth Supplemental Indenture dated as of May 5, 2006, a Thirteenth Supplemental Indenture dated as of October 8, 2009, a Fourteenth Supplemental Indenture dated as of May 3, 2010, a Fifteenth Supplemental Indenture dated as of December 22, 2010, a Sixteenth Supplemental Indenture dated as of December 22, 2010, a Seventeenth Supplemental Indenture dated as of December 22, 2010, an Eighteenth Supplemental Indenture dated as of August 6, 2012, a Nineteenth Supplemental Indenture dated as of August 6, 2012, a Twentieth Supplemental Indenture dated as of August 6, 2013, a Twenty-

Board of Directors

CalAtlantic Group, Inc.

June 9, 2017

Page 2

First Supplemental Indenture dated as of November 6, 2014, a Twenty-Second Supplemental Indenture dated as of October 1, 2015, a Twenty-Third Supplemental Indenture dated as of October 1, 2015, a Twenty-Fourth Supplemental Indenture dated as of October 1, 2015, a Twenty-Fifth Supplemental Indenture dated as of October 1, 2015, a Twenty-Sixth Supplemental Indenture dated as of October 1, 2015, a Twenty-Seventh Supplemental Indenture dated as of May 31, 2016, and a Twenty-Eighth Supplemental Indenture dated as of June 9, 2017 (the “Twenty-Eighth Supplemental Indenture” and, together with the Base Indenture and the First through the Twenty-Seventh Supplemental Indentures, the “Indenture”), among the Company, the Guarantors, and The Bank of New York Mellon Trust Company N.A., as trustee (the “Trustee”).

In connection with rendering the opinions set forth herein, we have reviewed such certificates, instruments and other documents as we have deemed necessary or appropriate as a basis for such opinions, including the following:

Board of Directors

CalAtlantic Group, Inc.

June 9, 2017

Page 3

In giving the opinions hereinafter expressed, we have relied only upon our examination of the documents, instruments and certificates enumerated above, and in our examination of the foregoing, we have assumed, without inquiry, the following:

As to questions of fact on which our opinions are based, we have relied, without independent verification of the accuracy or completeness thereof, solely upon (i) the representations and warranties of the Company contained in the Indenture, (ii) the information set forth in the governing documents of the Guarantors enumerated above, and (iii) the

Board of Directors

CalAtlantic Group, Inc.

June 9, 2017

Page 4

statements and representations set forth in the certificates referred to above and in certificates of public officials.

Our opinions set forth herein are limited to the laws of the State of Florida.

Based on and subject to the foregoing, and to such other limitations and qualifications hereinafter set forth, we are of the opinion that:

1. Each of the Guarantors is a validly existing and registered general partnership, and its status is Active under the laws of the State of Florida.

2. Each Guarantor has the partnership power to execute and deliver the Twenty-Eighth Supplemental Indenture (and its guarantee included therein) and to perform its respective obligations thereunder.

3. The execution, delivery and performance by each of the Guarantors of the Twenty-Eighth Supplemental Indenture (and its guarantee included therein) have been duly authorized by all necessary partnership action on the part of each of the Guarantors.

4. The Twenty-Eighth Supplemental Indenture has been duly executed and delivered by each of the Guarantors.

We hereby consent to the filing of this opinion as an exhibit to the Registration Statement and to the reference to this firm under the heading “Legal Matters” in the Registration Statement, including the prospectus constituting a part thereof. In giving this consent, we do not thereby admit that we come within the category of persons whose consent is required under Section 7 of the Act or the rules or regulations promulgated pursuant to the Act.