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Solar panels and roofing NZ: what to check before installing or reroofing

Solar panels and roofing should be planned together. Since 23 October 2025, qualifying roof-mounted solar arrays can use new building-consent exemptions, but the Building Code, local planning rules and exemption conditions still apply. Before installing panels, check the roof’s remaining life, fixing method, wind conditions and weathertightness so you do not create an expensive remove-and-refit problem when the roof soon needs replacement. Sources: Building Performance; Building Performance; NZ Metal Roofing Manufacturers.

Applies to
New Zealand
Reviewed
21 October 2026
Evidence
6 linked source pages

Apply the answer

Check the roof before adding another system to it.

If the existing roof may need repair or replacement, coordinate that decision before committing to an array that may need to be removed later.

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What changed for roof-mounted solar consent in 2025?

Building Performance says new Schedule 1 exemptions for roof-mounted solar took effect on 23 October 2025. Arrays under 40 m² in wind conditions no greater than high have one exemption pathway; arrays over 40 m² or in higher wind require structural fixing design or review by a Chartered Professional Engineer to use the exemption. Sources: Building Performance; Building Performance.

Should you reroof before installing solar?

If the roof is likely to need replacement during the solar system’s useful life, coordinate the projects before installation. Removing and reinstalling arrays later adds labour and creates another round of roof interfaces. The decision should consider roof condition, corrosion, existing leaks, coating life and major flashings rather than roof age alone. Sources: Roofing Association of New Zealand; NZ Metal Roofing Manufacturers.

  • Ask for a roof-condition inspection before solar if the roof is older or already showing problems.
  • Record the exact mounting system and attachment points.
  • Keep product and workmanship warranties for both roof and solar systems.
  • Ask who is responsible if roofing must be removed under the array later.

Fixings and penetrations are roof details, not just solar hardware

Any roof fixing must preserve structure and weathertightness. Where a solar installation creates penetrations or service routes, the roof detail should follow the relevant roofing/product system rather than relying on improvised sealant. Sources: NZ Metal Roofing Manufacturers.

NZMRM also warns that condensate or discharge associated with services should not be directed onto metal roof cladding where it can create a corrosive local environment. Sources: NZ Metal Roofing Manufacturers.

Questions to ask the solar installer and roofer

  • What roof material/profile is present and what mounting system is compatible with it?
  • Does the array size/wind condition fit the consent exemption, and is engineering required?
  • Does the system penetrate the cladding or use profile/seam-specific clamps?
  • Who warrants the roof interface and for how long?
  • How are cables and services routed without creating water traps?
  • What happens to the panels if the roof needs repainting, repair or replacement?
  • Will the roof manufacturer/installer warranty be affected by third-party fixings?

Related questions

Do roof-mounted solar panels need building consent in NZ?

Many can now use Schedule 1 exemptions. The detailed pathway depends on array size and design wind speed; larger arrays or higher-wind sites require structural fixing design/review by a Chartered Professional Engineer to use the exemption. Sources: Building Performance; Building Performance.

Should I replace an old roof before getting solar?

If the roof is approaching repair/replacement or already has corrosion, leaks or coating failure, coordinating the reroof first can avoid paying to remove and reinstall the solar system later. Assess condition rather than age alone. Sources: Roofing Association of New Zealand.

Can solar installers just drill through metal roofing?

The fixing method must preserve structure and weathertightness and be compatible with the roof profile and materials. Any penetration needs a designed weathering detail, not simply a hole plus sealant. Sources: NZ Metal Roofing Manufacturers.

Sources and review notes

Prepared by RoofHub editorial. Reviewed . A source check confirms what a page states, not an independent inspection or invoice audit. Published project accounts are attributed to their publishers.

  1. primaryBuilding Performance: Solar panel and boundary setback building consent exemption changes (2025-10-22) - MBIE announcement of roof-mounted solar consent exemptions taking effect 23 October 2025. Building Code, district-plan and exemption conditions still apply, with structural and weathertightness risks to manage. Page checked 2026-10-21. Publication date shown above. · government
  2. primaryBuilding Performance: Notes for solar panel arrays: 14.1 to 14.4 - Current MBIE guidance for solar-array Schedule 1 exemptions. Roof-mounted arrays under 40 m² and not above high wind have one pathway; larger arrays or higher wind require structural fixing design/review by a Chartered Professional Engineer to use the exemption. Page checked 2026-10-21. Publication date not stated. · government
  3. primaryNZ Metal Roofing Manufacturers: Code of Practice v26.09: Roof penetrations - Current NZMRM roof-penetration guidance. Penetration detailing depends on hole size and shape, roof pitch and type, catchment area, position and durability/compatibility requirements. Page checked 2026-10-21. Publication date not stated. · industry-technical
  4. primaryRoofing Association of New Zealand: RANZ Re-Roofing Guide - RANZ describes this as an annually updated NZ consumer guide to reroofing materials, systems, terminology, scope and workmanship. Used for project-planning context rather than contractor ranking. Page checked 2026-10-21. Publication date not stated. · industry-technical
  5. primaryNZ Metal Roofing Manufacturers: Code of Practice v26.09: Preventative maintenance - Current MRM guidance on preventative maintenance in vulnerable areas, including severe marine micro-environments and unwashed areas. Used alongside the selected product manufacturer warranty and care requirements. Page checked 2026-10-21. Publication date not stated. · industry-technical
  6. primaryNZ Metal Roofing Manufacturers: Code of Practice v26.09: Penetration durability and compatibility - Current NZMRM guidance requiring compatible materials around penetrations and separate drainage of condensate or corrosive discharge rather than discharge onto metal roof cladding. Page checked 2026-10-21. Publication date not stated. · industry-technical

Original calculations are labelled as examples. Historical prices stay dated, missing fields stay unknown, and conflicting specifications are flagged. Sources are not endorsements or paid rankings. Read our methodology or report a correction.

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