There's a good article about the Houses of Worship that have been built and the sites for future Houses of Worship at:
Bahá'í House of Worship - Wikipedia, the free encyclopedia
Also I forgot about this but there are inscriptions above the entrances and alcoves that should be noted:
Nine Inscriptions Carved Above the Entrances of the Temple:
"The earth is but one country; and mankind its citizens."
"The best beloved of all things in My sight is justice; turn not away therefrom if thou desirest Me."
"My love is My stronghold; he that entereth therein is safe and secure."
"Breathe not the sins of others so long as thou art thyself a sinner."
"Thy heart is My home; sanctify it for My descent."
"I have made death a messenger of joy to thee; wherefore dost thou grieve?"
"Make mention of Me on My earth that in My heaven I may remember thee."
"O rich ones on earth! The poor in your midst are My trust; guard ye My Trust."
"The source of all learning is the knowledge of God, exalted be His glory."
BAHÁ'U'LLÁH
Nine Inscriptions Appearing In the Temple Alcoves:
"All the prophets of God proclaim the same faith."
"Religion is a radiant light and an impregnable stronghold."
"Ye are the fruits of one tree and the leaves of one branch."
"So powerful is unity's light that it can illumine the whole earth."
"Consort with the followers of all religions with friendliness."
"O Son of Being! Thou art My lamp and My light is in thee."
"O Son of Being! Walk in My statutes for love of Me."
"Thy Paradise is My love; thy heavenly home reunion with Me."
"The light of a good character surpasseth the light of the sun."
BAHÁ'U'LLÁH
Baha'i House of Worship, The
Light of inspiration
"The first concept was a temple of light," said Mr. Hariri, a Toronto-based architect.
"Light, after all, is the connecting force of the universe and all religions celebrate its spiritual delights.
"That was our starting point -- that it would glow with a dreamlike serenity which will explore the range of the phenomena of light and shadow in continual interaction."
Stimulation for that inspiration, he said, came in part from a close examination of the dome of the Baha'i Temple in Wilmette, Illinois, in the United States.
From an article about the future Temple being erected in Santiago, Chile:
Bahai News - Casting light on design of Temple