The conservation standards a heritage project is judged against

Character-defining elements, the term everything turns on

A heritage decision rarely concerns the whole building equally. It concerns the specific features that carry the building's heritage value, which the Standards call character-defining elements. On a Craftsman house these are often the roof form and eave brackets, the porch and its columns, the window pattern and sash divisions, the original cladding profile, and interior millwork where the interior is part of the value.

Identifying these correctly is the first task on any heritage project, because the Standards treat them differently from everything else. Work on a part of the building that carries no heritage value is an ordinary renovation decision. Work on a character-defining element is a conservation decision with a documented test behind it.

This is also why two heritage houses on the same street can face different answers to the same request. The elements that carry value differ, and so does what may be changed.

Three treatments, and choosing the right one

The Standards define three conservation treatments, and a project declares which one it is following. Preservation protects and stabilises the place as it is. Rehabilitation adapts the place for a continuing or new use while protecting its heritage value. Restoration returns the place to a known earlier state, removing later features and replacing missing ones from that period.

Most residential heritage work in Metro Vancouver is rehabilitation, because the house continues as a house while gaining modern systems, insulation, and often additional space. Restoration in the strict sense is less common, and it needs documentary evidence of the earlier state rather than an opinion about how the house probably looked.

Declaring the treatment early shapes every later argument. A proposal that removes a 1960s addition is straightforward under restoration and needs a different justification under rehabilitation.

The standards that decide most residential arguments

Four of the fourteen standards carry most of the weight on a house project. Standard 1 requires conserving heritage value and says not to remove, replace, or substantially alter intact or reparable character-defining elements. The word reparable is doing heavy work there: a window that can be repaired is not a candidate for replacement under this test.

Standard 3 requires conserving heritage value by adopting an approach calling for minimal intervention. Standard 6 requires evaluating the existing condition of character-defining elements to determine the appropriate intervention, and using the gentlest means possible. Together these two set the burden of proof on the person proposing the larger intervention.

Standard 7 governs repair and replacement. It requires maintaining character-defining elements on an ongoing basis, repairing them by reinforcing their materials using recognised conservation methods, and replacing in kind any extensively deteriorated or missing parts where surviving prototypes exist. Replacing in kind means matching the original, and a surviving prototype is what makes the match evidence based rather than invented.

Additions, and the rule that surprises owners most

Standard 11 covers new additions and related new construction. It requires conserving the heritage value and character-defining elements, and making the new work physically and visually compatible with, subordinate to, and distinguishable from the historic place.

Owners are usually comfortable with compatible and subordinate. Distinguishable is the one that surprises, because it asks that a viewer be able to tell which part is original and which is new. An exact copy of the original detailing, which many owners assume is the respectful choice, works against this standard.

In practice this shapes additions towards a clear separation: a simpler treatment on the new work, a visible change of plane or material at the junction, and detailing that reads as of its own time while sitting quietly beside the original.

Standard 2 adds a point worth knowing before demolition planning starts. Changes that have themselves become character-defining elements over time are to be conserved, so a later addition is not automatically a candidate for removal.