How are solar systems and electrification works delivered on school and council buildings?

Solar and electrification work on a public asset involves three parties beyond the builder and the client: the network operator, the certifier, and whoever will operate and monitor the system afterwards.

Most of the difficulty is in those relationships rather than in the installation.

Can the roof carry it

A solar array adds load, and it adds uplift.

Which means the roof structure is assessed before the array is sized, and on an older building that usually requires investigation rather than reference to a drawing. Purlin spacing, member capacity, the condition of the fixings and whether the sheeting itself can take a penetrated or clamped fixing all determine what can be installed.

The condition of the roof is the related question. Installing a twenty-five year array over sheeting with eight years left means removing and reinstalling it, so the roof replacement and the solar installation are considered together, which is the work described in [roof replacement on an occupied building](/answers/roof-replacement-on-an-occupied-building).

Penetrations are the durability risk. Each fixing through sheeting is a potential leak, and the flashing detail at each one is what decides whether the roof is still watertight in ten years.

The electrical capacity question

The limiting factor is frequently not the roof, it is the board.

An existing switchboard on an older school or council building may have no spare capacity, no space for the required protection, and a main supply sized for a building without air conditioning. Which means the solar connection becomes a switchboard upgrade with its own programme and its own authority involvement, as set out in [electrical upgrades in occupied buildings](/answers/electrical-upgrades-in-occupied-buildings).

The network connection has its own limit. A network operator sets a maximum export for a connection, and approval is required before installation rather than after. On a larger system the approval process is the longest item in the programme, which is why it is lodged early, in the same way as the approvals in [service location and utility relocations](/answers/service-location-and-utility-relocations).

Electrification works

Replacing gas appliances and gas heating with electric equivalents is a different piece of work with a different constraint: the building cannot be without the service.

Which means the sequence matters more than the installation. The replacement plant is installed and commissioned before the existing service is decommissioned, and the changeover happens in a defined window. On a school that window is usually a holiday period, and on a council facility it is scheduled around the operating programme.

The capacity question returns here, because electrifying heating and hot water adds load to a board that may already be at its limit, and the two pieces of work have to be planned as one.

Gas decommissioning is its own item, with the isolation, the removal and the certification documented.

Installing on an operating site

Roof work above an occupied building means exclusion zones below, edge protection, and a plan for anything that could fall. The controls are those described in [working at height on occupied buildings](/answers/working-at-height-on-occupied-buildings).

Deliveries and the crane or hoist for the panels need a position and a route, which on a school site competes with pedestrian movement, and that is managed as set out in [traffic management and deliveries to a live site](/answers/traffic-management-and-deliveries-to-a-live-site).

The electrical work frequently requires a shutdown, which is programmed against the operating calendar rather than against the construction programme.

Metering, monitoring and handover

A system nobody can read is a system nobody maintains.

Which means the handover includes metering that separates generation, consumption and export, monitoring the asset owner can actually access, and a plain explanation of what normal looks like so an abnormal reading is recognisable.

The documentation includes the array layout, the string configuration, the inverter settings, the network approval, the electrical certification, and the maintenance requirements including panel cleaning and inverter servicing. Those sit in the pack described in [handover documentation and operation manuals](/answers/handover-documentation-and-operation-manuals).

Shutdown and isolation procedures matter particularly here, because a solar array is energised in daylight regardless of whether the building's supply is off, and anybody working on that roof afterwards needs to know it.