Options for reducing weathertightness risks

For weathertightness, options to reduce risk and improve value may include the following:

Claddings

• Adding a drained and vented cavity.
• Changing the cladding type, for example, from a monolithic finish to a bevel-back weatherboard.
• Removing pergolas and other structures attached to the building through the cladding.

Decks

• Roofing over or building in waterproof decks (provided this can be accommodated within current RMA requirements).
• Removing cantilevered membrane-covered waterproof decks completely (an option may be to construct a new deck that is separated from the building envelope). 
• Lowering the finished level of waterproof decks to be below the adjacent floor level or incorporating drainage adjacent to the wall of the building or adding a threshold step at doorways. 

Roofs

• Removal of parapets. 
• Simplifying complex multi-pitch roofs.
• Repitching a flat roof with a change of roof cladding.
• Replacing  internal gutters with external gutters.
• Adding or extending eaves or verandas.

Windows

• Replacing raked and curved window heads (or sills) with square-topped units, including replacement of all units with new.

Framing

• Using framing with a higher level of preservative treatment (for example, H1.2 boric) than that used originally.

Other

• Improving the drainage of surface water from around the building.
• Incorporating a rigid air barrier, even if one was not required originally.

See risk evaluation for more on weathertightness risk factors.

Back to top

What to consider

When considering design changes to lower weathertightness risk, designers will need to confirm that:

• the changes to the shape and form of the building are permitted under the district plan, preferably without the need for a notified planning application
• the structure of the building can accommodate the new construction
• changes address the weathertightness issues with the building and future risk is lowered
• a Code compliance certificate will be forthcoming if such work is built as consented
• the client understands the changes and the visual impact they will have.

Removal of weathertightness risk. The image on the left shows the original house, while the image on the right shows the house after remediation, with different cladding and with risk features such as the pergola and the curved-top window removed.