RENOVATE OR RAZE AND REBUILD
Factors to be considered are the depth and condition of the current foundation or basement, the current lot coverage (structural and impervious surfaces now covering the acreage divided by the total acreage as a %), aesthetic appeal, historic value (is the house registered?), and the building envelope (can the existing walls and roof be properly insulated and vented to keep the cost for fuel at a reasonable level?).
in some towns, if a structure is razed (torn down), a new structure of the same size and with the same setbacks may not be able to be built. New rules may apply regarding allowable height, set-backs off the property boundaries or the lake, drainage, first-floor finish elevation above the mean high water line and 100-year flood zone (if a lake property).
Sometimes it may be practical to keep the existing foundation in place (and perhaps add courses of block to make it taller) then remove the existing frame walls and roof so that the space can be completely opened up without existing walls that may limit peripheral vision.
If the existing structure can be renovated to make it viable for use year-round, then typically the investment will cost less than starting over, depending upon the extent of the site work or restoration of the site in addition to updating the structure.
When the location of an existing structure isn’t ideal, however, building a new home on the lot may be the best alternative ... and there are options for razing the existing house such as a fire controlled by the fire Department as a practice drill or select craftsmen who will preserve some of the materials for re-installation.
Realtors always say “location, location, location” is what sells but deciding how to maximize the potential of a particular location takes some consideration!