Solar for townhomes and duplexes

Pull your deed or your HOA’s declaration and look for the words “fee simple” or “lot.” A fee-simple townhome means you own the ground under your unit and the structure on it, including the roof, and we treat it like any other single-family install. A condominium declaration, by contrast, gives you an airspace unit and makes the roof a common element owned by everyone. Attaching panels to a common-element roof needs association approval and often an amendment to the declaration, which rarely happens for one owner.

Some developments blur the line: townhome-style buildings organized as condos, or planned communities where the HOA carries the roof insurance and reserves for replacement even though owners hold title. In those cases the HOA usually has a say in roof penetrations because it will be paying to replace the roof later. We ask for the governing documents before quoting, because the answer changes the whole project. If it turns out you are a condo owner, the renter-or-condo page covers what still works.

Colorado’s solar-access statute, C.R.S. 38-30-168, voids any covenant that effectively prohibits solar on a building you own. An HOA can impose reasonable aesthetic conditions — flush mounting, black frames, keeping panels off a street-facing slope if a comparable slope exists — but it cannot require changes that significantly raise the cost or lower the output of the system. For a townhome with a single usable roof plane, that matters: if the only south-facing slope faces the street, a rule pushing the panels to the north side would cut production sharply, and the statute is on your side.

Practically, we prepare an architectural review packet: a roof layout, panel and racking spec sheets, the conduit route, and the color of the components. Most boards approve within one or two meeting cycles when the packet is complete. If a board says no outright, we point to the statute in writing and it usually resolves; the hoa-said-no page walks through that in detail.

A typical two-story attached townhome has one or two roof planes of perhaps 200–400 square feet each, less once fire-code setbacks along ridges and edges come out. That usually fits 8–14 panels at roughly 20 square feet apiece, or 3–6 kW. Production in Colorado runs about 1,300–1,600 kWh per installed kilowatt per year, so a 4 kW townhome system produces roughly 5,200–6,400 kWh annually — enough to cover most or all of a modest, gas-heated household’s electric use.

Conduit is the part that takes planning. The panels feed an inverter or microinverters, and the wiring has to get from the roof to your electrical panel without crossing into a neighbor’s attic or through a fire-rated party wall. We usually run it down an exterior wall on your side of the lot line or through your own attic space. Where units share an attic without a full firewall, the route stays entirely within your footprint, and we confirm that with the building department during the permit.

End units are the easy ones: more roof, an exposed side wall for conduit, and often a garage roof to add panels on. Interior units sometimes have room for a smaller array only. We would rather tell you that six panels is the honest maximum than sell you a system that hangs over the setback lines.

Nearly every duplex has two utility meters, one per unit, and a grid-tied solar system interconnects to exactly one of them. Net-metering credits land on that meter’s account and no other. If you own and occupy one half, the system goes on your roof section and feeds your meter; the other half is unaffected. If you own the whole duplex and live in one side, you can put a system on each roof half feeding each meter, or one larger system feeding only your side.

Owning both halves and renting one changes the economics. A system on the rental unit’s meter lowers the tenant’s bill, not yours, unless the lease includes utilities. Some owners size a system for the rented side and raise rent modestly to reflect lower utility costs; others keep it simple and only install on the owner-occupied half. As of September 2026 the federal residential credit is gone, but a system serving a rental may qualify for the business credit under §48E if placed in service by the end of 2027 — confirm with your tax advisor, because the rules differ from the homeowner credit.

A townhome garage usually has wall space for a Tesla Powerwall 3 or a SigenStor stack and a Level 2 charger, and the attached-garage location keeps them out of the weather. What it often lacks is electrical-panel capacity: many attached homes have 100- or 125-amp panels, and adding a charger, a battery, and solar together may call for a panel upgrade or a load-management device. We look at the panel label before promising anything.

One battery covering a 3–6 kW townhome array is usually plenty for Xcel’s 5–9 pm on-peak window and for a wildfire shutoff lasting a day. If backup matters more than savings, a backup-loads panel that carries the fridge, furnace blower, internet, and a few circuits costs less than whole-home backup and fits the small-panel reality.