Sunlight and Vastu-II

As per vastu rules if we construct the house where sunlight comes directly on the face of the house, we will get maximum energy required for our health as well as it can be used as solar energy. Now a days due to energy crises, sun light plays a vital role to save the energy. Vastu suggest that all rooms in a house must have at least one point from where direct sun light comes to the room. In old houses we see that Window near the roof was left open for this purpose, now a days due to multi story buildings the roofs are constructed only at a height of 10' and no provisions made for direct sun light which create problems at later stage. If we obey the vastu rules, there is no chance of spreading diseases from one person to others, being bacteria itself will not grow where direct sun light approached.