Solar Panel Installation Process: Step-by-Step Guide

Most Houston solar projects run three to six weeks from first consultation to power-on. The part people picture — crews on the roof — is only one to three days of that. The rest is design, permitting and waiting on your utility.

Here is what actually happens at each stage.

Step 1: Free roof assessment and energy consultation

Timeline: 1–2 business days

A technician walks your roof and checks the things that determine whether solar works and what it costs: shingle age and condition, decking, existing penetrations, rafter spacing, and your electrical panel’s capacity and busbar rating.

Alongside that, twelve months of your CenterPoint or TNMP usage gets pulled and reviewed. Usage history matters more than roof size — it determines system sizing. A shade study, run both by satellite and on site, maps how much sun each roof plane actually receives between 9am and 4pm.

You should leave this stage with a written production estimate and a real price. Be wary of anyone quoting a firm number without having looked at your roof or your bills.

Step 2: Custom system design and proposal

Timeline: 3–5 business days

Your roof gets modelled in 3D and panels are laid out plane by plane, with per-panel shade simulation feeding the production estimate. Equipment is selected here too — and in shaded Houston neighbourhoods this is where microinverters or optimisers get specified instead of a single string inverter.

The proposal should show system size, annual production, equipment makes and models, a 25-year savings projection, and cash versus financed options side by side. If you might add a battery later, say so now; a battery-ready hybrid inverter chosen at this stage saves an expensive swap later.

Step 3: Permitting and HOA approval

Timeline: 2–4 weeks — the longest stage

Inside city limits you need a City of Houston building permit and an electrical permit, both filed with stamped engineering drawings. Outside city limits, the county handles it. Separately, an interconnection application goes to your utility — CenterPoint across most of the metro, TNMP in parts of Fort Bend and surrounding counties.

Most Houston-area permits clear in 10–15 business days. If your neighbourhood has an HOA, an architectural review packet goes in parallel. Texas Property Code 202.010 limits how far an HOA can restrict solar, and most submissions are approved.

Your installer should file all of this. You should not be standing in a permit office.

Step 4: Professional installation

Timeline: 1–3 days

Racking goes down first, lag-bolted into rafters with flashing that tucks under the existing shingle course — the same method used for a vent or skylight. Then panels are mounted and torque-checked, the inverter is set, and conduit, wiring and grounding are run to your service panel.

Expect one brief planned power interruption while the system is tied into your panel. You need to be home at the start of day one for panel access and a walkthrough, but not for the whole job.

Step 5: Inspection, activation and monitoring

Timeline: 1–2 weeks

A city or county inspector signs off on the electrical work. Then the utility issues Permission to Operate — the legal green light to energise. Until PTO lands, your system stays switched off, however finished it looks. This wait is normal and largely outside anyone’s control.

Once activated, monitoring gets configured on your phone, production is verified against the design estimate, and warranty documentation is handed over.

What slows a Houston project down

• Panel upgrades. Older homes with 100-amp service often need a main panel upgrade, which is its own permit.
• HOA review cycles. Some boards meet monthly, which can add weeks.
• Roof repairs found at assessment. Better discovered now than after the array is up.
• Utility backlog. PTO queues lengthen seasonally.

For the full version of this process with timelines and photos of each stage, see our how it works page. When you are ready, book a free roof assessment.