You can access that node directly from the umbraco helper, assuming that the homenode is at the root:

 var homenode = Umbraco.ContentAtRoot().FirstOrDefault();
 var telephone = homenode.Value("telephone");

or if, it's a child of the root node:

var rootNode = Umbraco.ContentAtRoot().FirstOrDefault();
var homeNode = rootNode.Children().Where(x => x.ContentType.Alias == "homeNodeContentAlias").FirstOrDefault();
var telephone = homeNode.Value("telephone");

Replace "homeNodeContentAlias" with the node content alias.

or relative, from current node:

var homeNode = Model.AncestorOrSelf(1);
var telephone = homeNode.Value("telephone")