There are two sides of new construction in historic districts. Some believe that new construction should not mimic historic so as to not decieve the person viewing it. Others believe that new architecture MUST look new in an area.
I believe that new construction can blend effectivly with old. I find nothing more visually upsetting that a New Glass and Metal monstrocity on an historic block. As this Red example shows new is not necessarily better and overwhelms the Italianate to its left.
Many take a more historic approach that while identifable as new are more in scale, materials and style with their more historic neighbors. The new brownstones shown here present a more correct scale massing. Nor do they visually disrupt the eye and take away from historic homes on the block.
Neighborhoods need to take a more proactive role in determining just what goes in their neighborhoods. ask yourself which would you rather have next door to your 125 year old home?