To change the location of the generated output report along with other project reports the outputDirectory property of both the maven-site-plugin and maven-surefire-report-plugin should be set to the desired alternative location. For more information, see the documentation of the Maven Site Plugin.
<project>
[...]
<reporting>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-report-plugin</artifactId>
<version>3.0.0-M3</version>
<configuration>
<outputDirectory>${basedir}/target/newsite</outputDirectory>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-site-plugin</artifactId>
<version>2.1</version>
<configuration>
<outputDirectory>${basedir}/target/newsite</outputDirectory>
</configuration>
</plugin>
</plugins>
</reporting>
[...]
</project>
Please take note that if the outputDirectory of the Site Plugin is not configured, the output location of the Surefire report will still be the default.