Sizing Guide

Solar for Multi-Family and Duplex Properties

Multiple units, multiple meters, and sometimes multiple owners — multi-family solar has its own specific wrinkles worth understanding upfront.

Separate meters usually mean separate solar accounting

If each unit has its own utility meter, solar production typically needs to be allocated to a specific meter or split across them through a virtual net metering or similar arrangement — not every utility supports this equally well, so checking your specific utility's multi-meter solar policy matters before assuming a single system can simply offset the whole property.

Owner-occupied vs rental changes the incentive calculation

An owner living in one unit while renting others has a more straightforward case for solar (they directly benefit from their own unit's savings) than a landlord renting out all units, where the classic split-incentive problem applies — the owner pays for solar but tenants may get the electricity savings unless lease structures account for it.

Sizing for shared versus individual loads

Common area loads (shared laundry, hallway lighting, a shared well pump) can be sized and offset separately from individual unit usage — worth mapping out which loads are shared versus individually metered before finalizing a system size with the solar panel calculator.

Roof space and structural considerations scale with the building

Larger multi-family roofs sometimes support bigger systems than a comparable single-family home, but also may have more complex roof structures (multiple sections, shared walls, different ownership of roof areas in condo situations) worth confirming before assuming full roof availability.

HOA or condo association approval may be required. For attached or condo-style multi-family properties, association rules can affect what's allowed on shared or individually-owned roof sections — check governing documents before assuming individual unit owners can install solar unilaterally.

Frequently asked questions

Can each unit in a duplex have its own separate solar system?

Yes, if each unit has independent roof access and its own electrical service — this avoids the shared-meter complexity but means each system needs to be separately sized, financed, and permitted.

Does landlord-installed solar benefit tenants directly?

It depends on the lease and billing structure — some landlords include utility costs in rent and capture the solar savings themselves, while others pass metered savings through to tenants; this should be clarified explicitly in lease terms.

Written by the Solargrin team. Estimates only — verify specifics for your own equipment and utility before making a purchase decision.
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