In Mumbai many buildings have a longer East-West axis. How is that energy balanced?
It can be balanced with methods taught later. A good immediate remedy is to place the deity in the exact West of the home so that it faces East; when the deity looks to the East, the direction corrects itself.
Related questions
In my East-facing house the temple had to be on the North wall, so the gods face South; is that wrong?
Do not make the gods face South; it brings heaviness, for example interviews go well but give no result. Place them on the West wall instead so that they face East.
Our mandir is in the Brahmasthan and Lord Shiva faces West; is that a problem?
Do not worry about Lord Shankar facing West; worry only about the South, and even Hanuman ji may face South. If a deity ever faces a wrong direction, fix a mirror directly in front of the deity.
The West is best for the temple. If the West is a balcony, can it be covered and the deities hung, since they are not consecrated?
Hanging is ruled out for consecrated deities: if the idols are pran-pratishthit (consecrated), they must never hang.
A wooden temple with elephant figures stands in the North-East. Is that fine?
Elephant figures should stand on something solid, not hang in the air. The temple can stay, but a temple with elephants is better placed in the West.
An 80 x 50 shed has its floor sloping North but its roof sloping West. Is that fine?
No, the westward roof slope is wrong. It disturbs the energy current, so some trouble will persist there, and the roof slope has to be corrected.
Can a mandir face North or West?
A North-facing mandir is fine; temples of God are often kept North-facing. A West-facing mandir is moderate.