| Recommended | Not Recommended |
| Roofs |
| 6 | Protecting and maintaining a roof by cleaning and maintaining the gutters, downspouts and flat roof drains, and replacing deteriorated flashing in kind. Roof sheathing should also be checked for proper venting to prevent moisture condensation and water penetration, and to ensure that materials are free from insect infestation. | Failing to maintain roofs on a cyclical basis. Failing to replace deteriorated flashing, or to clean and properly maintain gutters and downspouts and flat roof drains so that water and debris collect and damage roof fasteners, sheathing and the underlying structure. |
| 8 | Stabilizing deteriorated roofs by structural reinforcement, weather protection or correcting unsafe conditions, as required, until repair work is undertaken. | Removing deteriorated roof elements that could be stabilized or repaired. |
| 12 | Testing proposed interventions to establish appropriate replacement materials, quality of workmanship and methodology. This can include reviewing samples, testing products, methods or assemblies, or creating a mock-up. Testing should be carried out under the same conditions as the proposed intervention. | |
| 13 | Documenting all interventions that affect the building's roof, and ensuring that the documentation is available to those responsible for future interventions | |
| Windows |
| 4 | Assessing the condition of windows, doors and storefronts, including hardware, early in the planning process so that the scope of work is based on current conditions. | |
| 6 | Protecting and maintaining windows, doors and storefronts by using appropriate surface treatments, such as cleaning, rust removal, limited paint removal, and reapplying protective coating systems in kind. | Failing to adequately maintain windows, doors and storefronts on a regular basis. |
| 9 | Stabilizing deteriorated windows, doors and storefronts by using structural reinforcement, and weather protection, or correcting unsafe conditions, as required, until repair work is undertaken. | Adding protective glazing or exterior storms to stained glass elements, without the involvement of a specialist conservator |
| 14 | Documenting all interventions that affect the building's windows, doors and storefronts, and ensuring that the documentation is available to those responsible for future interventions. | |