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Services›Free System Design

A free system design,
drawn by an engineer.

Send a power bill and your address. An engineer sizes the system for your roof and emails a ready-to-checkout cart with the wiring diagram.

One working day
No obligation to buy
Service 01 of 03
Most orders start here
Design fee, every system
$0
Parts list, wiring diagram and a permit pack — usually back the same working day.
Held for seven days
Overview

Your bill in. A checked cart out.

Calculators guess from your ZIP code. An engineer looks at your roof from satellite data, your twelve months of use and the panel you already eyed in the store — then builds the cart that actually fits.

You get one link with every part priced to the cent, a wiring diagram your installer or inspector can follow, and a delivery date we hold for a week while you decide.

1day
parts-list turnaround
$0
design fee, no obligation
7days
delivery date held
Sunbox engineer with a headset talking to a customer at her desk, roof layout on screen
Engineer desk · Foundry Rd
Checked by a person
An engineer signs every parts list
Free parts list · one working day

Two fields. One checked cart.

Two fields, then attach a bill in the reply email. No calls unless you ask, and nothing is ordered until you check out.

    No calls unless you ask.

    What lands in your inbox
    Built by an engineer, not a calculator — usually the same working day.
    System size for your roof
    Panel count, layout and yearly output.
    A cart, priced to the cent
    Every part, one link, nothing missing.
    Wiring diagram + permit pack
    Ready for your inspector or installer.
    A delivery date
    Held for seven days while you decide.

    Is the design really free?

    Yes. The parts list, wiring diagram and permit pack cost nothing and carry no obligation. You only pay if you check out the cart.

    What do I need to send?

    Your email, your address and a recent power bill — a photo of it is fine. If you already picked a panel in the store, mention it and we design around it.

    How long does it take?

    Usually one working day. Engineers work Mon–Sat, 7:00–⁠19:00, and anything sent on a Sunday is answered Monday.

    Can I change the cart afterwards?

    Yes. Swap any part before checkout and the engineer re-checks the cart. If a swap breaks the design, we tell you before you pay.

    Do you design for off-grid cabins too?

    Yes — the Cabin kit starts at $2,190 and the same engineers size it from what you plan to run there.

    System design FAQ

    Free design, answered.

    The five questions people ask before they send a bill.

    Not on the list?
    Our full FAQ covers ordering, delivery, returns, warranty and permits.
    What’s included

    Everything in the design, at no charge.

    The same eight things go into every parts list, whether it ends up a cabin kit or a whole-home bundle.

    Twelve-month use check
    From the bill you send, month by month.
    Roof read from satellite
    Pitch, shade and usable area.
    Panel layout
    Rows, rails and spacing drawn to scale.
    Inverter matched to it
    String or hybrid, sized to the array.
    Battery sizing (if wanted)
    For evenings or backup, not both by default.
    Wiring diagram
    Single-line, ready for an inspector.
    Permit pack
    Spec sheets your county asks for.
    Ready-to-checkout cart
    One link, every part priced.
     
    Spec sheet

    What every parts list contains

    Turnaround
    One working day
    Fee
    $0 — no obligation
    Checked by
    A Sunbox engineer
    Diagram
    Single-line wiring, PDF
    Permit pack
    Spec sheets + layout
    Delivery date
    Held for 7 days
    Hours
    Mon–Sat · 7:00–⁠19:00
    Designed here, built there

    Three homes that started with a parts list.

    Bundles drawn from a power bill and a roof photo — with what each family ordered and who fitted it.

    Two-storey Fort Collins house with black solar panels on a grey shingle roof

    Nair Family Home

    Whole-Home Bundle · evening use covered · Boulder
    5.2 kW + 13.5 kWh
    Utility room wall with a hybrid inverter and a white home battery

    Utility-Room Battery Retrofit

    Battery added to a 2022 roof · Aurora
    13.5 kWh
    Timber-clad family home with a solar roof and an electric car charging on the drive

    Larkspur Home + EV

    Roof, battery and charger on one pallet · Castle Rock
    8.6 kW + EV
     
     
     
     
     
     
     
    Free parts list · one working day

    Send us your roof. We’ll send the cart.

    Share a recent power bill and your address. An engineer sizes the system and emails a ready-to-checkout cart within one working day.

    Rather talk?

    Talk to an engineer, not a call centre.

    +1-⁠555-⁠0168
    Mon–Sat · 7:00–⁠19:00
    hello@sunboxsupply.example
    Answered the same working day