The benchmark for openness in the realm of ecclesiastic building must surely be Bernini's colonnade design for the Piazza San Pietro in Rome. The two wings of the colonnade extend from the portico of the great basilica like a pair of welcoming arms, embracing all of humanity.
The antithesis of openness can be seen, if not quite believed, in the frightfully ugly Hollywood Seventh Day Adventist church at the intersection of Hollywood Boulevard and Van Ness Avenue, referred to euphemistically by locals as the Purple Church for its covering of small lavender tiles.
The building was designed by architects Burman + Rasmussen in 1961 in a style that can grudgingly be called optimistic brutalism. In all fairness to Burman and Rasmussen, I'm not sure to what extent their original plans have been altered in the intervening decades, but it's clear that the original church was vaguely "inspired" (I'm groping for words here) by Le Corbusier's Nôtre Dame du Haut in Ronchamps, built just a few years earlier. The mast on top (for channeling alien frequencies?) pays tribute to the phonograph needle atop the Capitol Records Building, just down the boulevard, and to the bristling antennae of the CBS Building, not far away on Sunset.
In contrast to Le Corbusier's soaring prow of a ship on its way to heaven, the execution of the derivative church in Hollywood is clumsy and earthbound, like an ark converted to a detention facility. The entrance, from the parking lot on Van Ness Avenue, is not a façade but a set of institutional aluminum doors and windows better befitting a satellite office of the DMV than a house of God, should He or She exist.
On the south side, the fenestration of the apse takes the form of defensive slit-like loopholes of the sort originally intended to shoot arrows from in medieval fortifications.
The presence of the noisy Hollywood Freeway right next door is also problematic. (Interestingly, the new cathedral of Los Angeles is also shunted right up against the Hollywood Freeway, instead of marking the center of town, as a European cathedral would.)
The most disturbing aspect of the entire Seventh Day Adventist property is that the church building is enclosed in a walled compound that bunkers worshippers inside like branch Davidians and intimidates casual passers-by outside with a 20-foot-high expanse of concrete block, itself protected on the Hollywood Freeway side by cyclone fencing and on the east and north sides by a thick black steel palisade.
This is possibly the least inviting design for a church ever conceived. Oh, and Happy Easter.