Other Relevant Information. Results Presentation 1S2021

OBRASCON HUARTE LAIN, S.A. (“OHLA” or the “Company”), pursuant to article 228 of the consolidated text of the Spanish Securities Market Act approved by Royal Legislative Decree 4/2015, of 23 October, hereby notifies the Spanish National Securities Market Commission (Comisión Nacional del Mercado de Valores) (“CNMV”) the following

OBRASCON HUARTE LAIN, S.A. (“OHLA” or the “Company”), pursuant to article 228 of the consolidated text of the Spanish Securities Market Act approved by Royal
Legislative Decree 4/2015, of 23 October, hereby notifies the Spanish National Securities Market Commission (Comisión Nacional del Mercado de Valores) (“CNMV”) the following

DISCLOSURE OF OTHER RELEVANT INFORMATION

Due to an error in the previous communication, OHLA confirms that next Thursday, July 29, 2021 after the market close, 1H 2021 results will be released and the management
team will have a call for analysts and investors on Friday 30 July at 9:30 a.m. Madrid time.

The details of the conference will be available at: www.ohla-group.com, but it is anticipated that only will be available connection to the call via internet, no phone
numbers will be available.

The recording of the call will be available on the web during a week.

Madrid, 27 July 2021.