As you notice, it's done frequently but still not recommended. Painted brick seems like a good approach on a new structure in a historic district because even an inexpensive modern brick can look like it belongs with the right color paint. Brick will absorb moisture, however, whether it comes from below grade or - assuming your brick is a veneer - from vapor pressure in the cavity. The coating will need to be 'breathable' if the brick is to dry to the outside; the thought of brick faces popping off after a few cycles of freeze thaw is what the Brick Institute is concerned about. I have specified lime-based paints for historic brick buildings (check out Virginia Lime Works) - this is 'whitewashing' but you can have pigment added and it can be applied in a number of coats to be opaque. The application requires a bit more care and you'll want to have your painter experiment some.
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Sabina Weitzman, Architect
Fredericksburg VA
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