City officials have tried to curb the demolition of historic homes by imposing delays on knockdowns — partly to preserve some of Newton’s stately Victorian and Italianate homes, partly to stave off the rise of new homes filling out local neighborhoods.

But officials are cutting developers and property owners some slack under the delay rule by waiving it on projects that leave historic homes standing. They’re encouraging builders to upgrade the homes, and add on new garages, kitchens, bedrooms, and living space