Virtual host and document root problem

I have a site for example www.house.com and an other site www.garden.com on the same server.

So I create two virtual host on my server.

<VirtualHost www.house.com>
DocumentRoot /var/www/html/house
ServerName house.com
</VirtualHost>

<VirtualHost www.garden.com>
DocumentRoot /var/www/html/garden
ServerName garden.com
</VirtualHost>

now I have a sub part of my site www.house.com, i want to acces by a new dns name like www.kitchen.com, who was the same that www.house.com/kitchen.

So I reserved the www.kitchen.com but I can't find how to configure my virtual host, because if I configure my DocumentRoot I do like this:

<VirtualHost www.kitchen.com>
DocumentRoot /var/www/html/house/kitchen
ServerName kitchen.com
</VirtualHost>

I have problem in the organisation of my site because I have some stuff on my /var/www/html/house that I use for all the site!

I hope you anderstand my problem, I'm sure that a lot of people have the same problem and alose the solution.

So if somebody can help me to explain how to configure apache to do this think, thanks.