Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_70 ( height__m_ INTEGER, year_built VARCHAR, name VARCHAR )

### Question ###
What is the sum of the heights in meters for the commerzbank tower built after 1984?

### Accurate SQL ###

SELECT SUM(height__m_) FROM table_name_70 WHERE year_built > 1984 AND name = "commerzbank tower"