PV-ready roof planning checklist

Measure usable, not gross, roof area

Orientation and pitch shape generation but do not decide the scheme alone. Rooflights, chimneys, vents, safety zones, access and moving shade fragment apparently open surfaces. A layout should show real obstructions and service routes. Alternative roof faces or outbuildings may be worth testing where design and local rules permit.

Early coordination prevents roof services and modules competing on site. A concept layout has limits because products and connection terms may change. Reserve clear zones and decision dates rather than locking an unsupported product choice.

Record orientation, pitch and every obstruction
Map seasonal shade
Check local access and emergency provisions
Identify an optional expansion zone

Decision: annual yield or demand profile?

Maximum annual output is not the only objective. A qualified designer can compare orientations against the timing of household loads, a heat pump or vehicle charging without promising a particular saving.

Coordinate structure, attachment and weathering

Modules and rails add dead load and transfer wind and snow actions. A structural professional must assess the actual site, roof form and attachment. Generic claims about timber or masonry construction are insufficient. Penetrating, clamped and ballasted systems produce different load paths and details.

Roof-covering responsibility must be explicit. Attachments, cables and bonding should not compromise drainage, membranes or ventilation. Record who approves the detail, installation and weather check. Structural assessment and electrical work are not safe homeowner engineering tasks.

Give PV load assumptions to the engineer
Document attachment zones and load paths
Combine penetrations on one drawing
Define roofer and PV contractor responsibilities

Plan the electrical journey and handover

Trace the route from modules to inverter, distribution board, meter and grid point. A short route helps, but protection, heat, access and fire requirements govern the solution. The inverter needs a suitable serviceable location. Battery storage is a separate decision with its own space, protection and operating case.

Contact the local network operator and a qualified electrician early about application and metering. Requirements vary by jurisdiction. Handover should include schematics, string layout, protective devices, labels, commissioning records and shutdown information.

Schedule network and metering decisions
Reserve protected cable routes
Allow inverter access and heat dissipation
Plan visual inspection and service access

Hypothetical coordination example

A hypothetical south-facing roof appears spacious. A coordinated overlay reveals clashes among a vent, rooflight, module rows and access route. The team moves the still-flexible vent, obtains a structural review of attachment zones and reserves a protected cable path. This avoids an improvised penetration after the roof is complete.

Pitfalls to avoid

Treating gross roof area as fully usable
Introducing attachment loads after structural design is complete
Routing cables and penetrations without one coordinated drawing

Frequently asked questions

Must solar face due south?

No. Other orientations may fit the load profile and site; model both total output and timing.

Can every roof carry PV?

There is no universal answer. Condition, structure, actions and attachment require project-specific review.

Should a battery be installed immediately?

Not necessarily, though space and electrical expandability can be considered now.

Can an owner pre-wire the array?

Cable design, protection and connections should be specified and completed by qualified professionals.

Related guides

Sources

These sources explain general planning principles, mainly in the German context. They do not confirm project scope, permission, funding or technical suitability. Local requirements need separate professional assessment.

Plan a PV-ready roof: structure, layout and connections