There is one saying in Upanishad, i.e. "OM ETIAKSHARA BRAHMA". It means that OM itself represents lord Brahma. All the anicent Rushis has done a research in Vedas and came with 51 letter/alphabets in Sanskrit languages. Each alphabet is the root of one lord in Hindu methodology.

From the above paragraph it is evident that alphabets in Sanskrit language has very good importance in Hindu methodology.That is the reason why Vastu Experts suggest favorable house direction with respect to the name.

Here in the below table, I'm giving the brief description of favorable house directions with respect to Nama Rashis.

House facing, main door facing	Favourable rashis and Name vargas.
East facing	Mesha, Karkataka, Simha and vrischika, Dhanu rashis ya, sa varga names
South Facing	Vrishaba, mithuna, karkatak, kanya, makara rashis ya, sa varga names
West facing	Vrishaba, mithuna, tula, dhanu rashis aa,ka,cha,tha varga names
North facing	Mesha, Karkataka, vrishabha, simha, kumbha, dhanu,meena rashis tha, ta, pa varga name