Can I redefine an XML Element definition?

Question

For example,

I would like to include <feetFromWater> in my <house> element. But here is the catch... I would like to keep the element name <house> and I do not want to modify the original definition.

FILE: baseProperty.mod

<!ELEMENT house               (%size;%stories;)>
<!ATTLIST house               %univ-atts;
                              outputclass CDATA #IMPLIED                         
>

FILE: beachHouse.mod (This file references baseProperty.mod)

<!ELEMENT beachHouse          (%size;%stories;%feetFromWater)>
<!ATTLIST beachHouse          %univ-atts;
                              outputclass CDATA #IMPLIED                         
>

Is there a way to do the following without renaming from <house> to <beachHouse>?