http://www.mtc.gov.on.ca/en/publicat...it_DHP_Eng.pdf
Here in Whitby where I live there are many Heritage designated homes with more being considered including the whole downtown area.. I know that once designated a homeowner is very limited in what can happen inside and outside of the home and must follow rigid guidelines as to the changes they might want to make. This includes repair/replacement of any parts of the home like wood trim, brick, additions must be approved and be in the style of the home etc. It can be a very expensive proposition to own a heritage home.