WpResidence uses these measurement options

$measure_array = array(
esc_html__('ft','wpresidence-core' ) => esc_html__('square feet - ft2','wpresidence-core' ),
esc_html__('m','wpresidence-core' ) => esc_html__('square meters - m2','wpresidence-core' ),
esc_html__('ac','wpresidence-core' ) => esc_html__('acres - ac','wpresidence-core' ),
esc_html__('yd','wpresidence-core' ) => esc_html__('square yards - yd2','wpresidence-core' ),
esc_html__('ha','wpresidence-core' ) => esc_html__('hectares - ha','wpresidence-core' ),
);

To change the translation you can use Loco Translate plugin steps explained here https://help.wpresidence.net/article/how-to-rename-theme-words-with-loco-translate/ 

Here is how you use Loco Translate to change ft to sqft

You can repeat this with any language and any measurement available

I will translate these to English

1st – Go to wpresidence-core-en_US.po

Find ft and translate it to sqft

2nd – Go to en_US.po from WpResidence Child Theme Languages

Translate ft to sqft

The measurement should be saved to square feet in Theme Options -> General -> Measurement Unit

When you check in front – you will see the measurement translation