[scjain]

Ayadi _shadvarga is a matrix of architecture and astrological calculations.  According to Samarangana Sutradhara Ayaadi-shadvarga is a set of six criteria:

1. aaya (gain)
   
2. vyaya (losses)
   
3. amsha
   
4. nakshatra
   
5. yoni
   
6. vara-tithi
   

which are applied to certain dimensions of the building and its astrological associations. The purpose of the exercise is to ascertain the longevity of the house as also the suitability to its owner. These norms are applied to temples too.

The term Aaya could be taken to mean increase or plus or profit;
Vyaya – decrease or minus or  loss;
Nakshatra,-
Yoni – source or the orientation of the building;
Vara- day of the week; Tithi – the day in lunar calendar for construction of building and performing invocation of Vastu Purusha..

The area of the structure is divided by certain factors assigned to each element of the Aayadi Shadvarga; and the suitability or longevity of the building is ascertained from the reminder so obtained.

Aaya :-
For instance, if the plinth area of the house is divided by 8; and the remainder is either 1 or 3 or 5, then these are called Garuda garbha, Simha garbha and Rishabha garbha, which are auspicious. Hence the plinth area of the building should be manipulated or altered to arrive at an   auspicious reminder. The reminders 1 to 8 are interpreted as good or bad, as indicated in the following table.
.Manasara says



Nakshatra :- Area is multiplied by 8 and product is divided by 7 the reminder is Nakshatra.from nakhsatra of house count to nakshatra of land lord and divide that value by 9 if reminder is 3 then loss of money,if five the loss of pride and if it is seven then death of landlord.

Vyay:_Divide Nakshatra of the house by 8 , the remainder is Vyaay . The Vyay is three types . When it it less then Aaya it is Yax Vyay and is more, then it is Rakshas Vyaay and when it it is equal to Aaya then it is Pishaach Vyay .Yax Vyay is good Rakshas Vyay is bad and Pishaach Vyaay is medium .


Vaar :-Area is multiplied by 8 and product is divided by 30 the remainder corresponds to solar days the first of which Sunday.
if it is Sunday or Tuesday then fear of fire in house rest days are good.

Ansh :- Add Area of the house , no of letters in name of the house and Vyay figure of the house and divide it with three and the remainder we get is called Ansh. If it is one then it is Indransh, two then Yamaansh and zero then it is called as Rajaansh.

[Manish Jain]

Aayadi constitutes six formulae Aaya, Vyaya, Yoni, Raksha, Vara and Tithi which are explained below. The remainder obtained by using these formulae determines whether it is a gain or loss. If it is a gain, then the structure is proportionate and stable and the dimensions are right. However if it is a loss, then  it means the dimensions are not right and should be suitably corrected.

1. Yoni is the remainder of  Breadth x 3 divided by 8
   
   
2. Vyaaya is the remainder of  Breadth x 9 divided by 10
   
   
3. Aaya is the remainder of  Length x 8 divided by 12
   
   
4. Raksha is the remainder of  Length x 8 divided by 27
   
   
5. Vara is the remainder of  Height x 9 divided by 7
   
   
6. Tithi is the remainder of  Height x 9 divided by 30