Ranch house lit as a Christmas mockup: C9 roofline, ridge and hips, red-bow wreath in the garage gable, wrapped columns, lit bushes, walkway stakes

How to Add Christmas Lights to a House Photo With AI

The single biggest unlock for closing Christmas light installs online — without ever stepping foot on the property — is showing the homeowner exactly what their house is going to look like lit up. Not a generic stock photo. Not a Pinterest example. Their house. Lit up. Looking magical. From one iPhone photo they texted you.

That is what AI house mockups do. The free tool at the top of this page builds the instructions for you: pick the roof sections, pick the colors, add any decorations, then copy the result into ChatGPT with the photo. The rest of this page explains the workflow and gives you the prompts by hand. It runs in ChatGPT, which most contractors already have on their phone. Below is the contractor's guide to doing it well — with the exact prompts I use, a real before/after example, and the workflow that gets the mockup into the homeowner's email the same day.

Quick Answer: Use the free Christmas Light Design Tool at the top of this page. Pick the roof sections, colors, and decorations, copy the instructions it writes, and paste them into ChatGPT with a photo of the house. ChatGPT returns the finished mockup in about a minute. Everything below shows you the workflow and the prompts behind it.

I am Jason Geiman. I scaled a Christmas light installation business from $2,000 to $1M+ with four crews, sold it in 2018, and now run Christmas Lights HQ and the 43,000+ contractor community at ChristmasLights.io. Here is what works.

Why AI mockups matter for Christmas light sales

Until 2024, the only way to show a homeowner what their house would look like lit up was to either drive out for an in-person walkthrough, take a guess and email a text quote, or send them a photo of a different house and say “something like this.” All three options leak deals.

The walkthrough wins on close rate but only scales so far — one truck, one route, one job at a time. The text quote loses to anyone who shows up with a visual. The “different house” example is even worse — it tells the homeowner you didn't bother to look at theirs.

AI mockups solve all three problems. You get the homeowner's actual house, lit up, in minutes. You can include it in an online quote you send within an hour of the phone call. That speed-plus-visual combination is what separates a quote that closes from one that goes quiet.

The before/after that makes this real

Below is what an AI mockup looks like in practice. Top panel is the kind of iPhone photo a homeowner texts you. Bottom panel is the AI-generated mockup of the same house lit up — what you include in their online quote email.

Plain daytime photo of a ranch house before Christmas lights, the kind a homeowner texts a contractorRanch house lit as a Christmas mockup: C9 roofline, ridge and hips, red-bow wreath in the garage gable, wrapped columns, lit bushes, walkway stakes
Left: the photo. Right: the mockup, made in ChatGPT from that photo using the instructions the tool at the top of this page wrote. Same house, same angle. Nothing added except the lights.

Mockup quality has gotten close enough to photoreal that homeowners don't think “AI” when they see it — they think “wow, that's our house.” That emotional reaction is what closes the sale. They are not comparing it to a perfect photo. They are imagining their family pulling in on Christmas Eve and feeling something.

What the tool at the top of this page does

It writes the instructions for you. Pick the roof sections, the bulb colors, and any decorations, and it builds a complete, house-specific set of instructions for ChatGPT. You copy them, open ChatGPT, attach the homeowner's photo, paste, and send. ChatGPT makes the finished picture in your own account.

Nothing uploads to this site. Your photo never leaves your browser, and the instructions are built right here on the page. If you want to control exactly where a run goes, the optional marking mode lets you draw the lines on the photo and download a placement guide to attach alongside it.

The prompts below are the same rules the tool uses, written out by hand, for anyone who wants to see or edit what is being sent.

The contractor's AI mockup workflow

  1. Ask for the photo on the phone. During the qualifier call, say: “Could you text me a photo of the front of the house? Daylight is best. Standing back across the street if you can.” Most homeowners send it quickly.
  2. Open Google AI Studio at aistudio.google.com (free). Upload the homeowner's photo.
  3. Paste your prompt (templates below). Customize the package — roofline, peaks, trees, wreath — based on what you discussed on the phone.
  4. Generate. Fast; varies by load. Inspect the result. If a window got changed or the trim color shifted, type a follow-up edit: “Keep the same windows but make the front door wreath 60 inches and add a red bow.”
  5. Download and email as part of the online quote. Subject line: “Here is what your house could look like this Christmas — quote attached.” That subject line gets opened.

The four AI mockup prompts that work

Copy-paste these. Customize the bracketed sections based on the package the homeowner is buying. All five work in ChatGPT with no changes.

Prompt 1: The full residential package mockup

Use this for most residential walkthroughs — roofline + bushes + wreath + tree.

Take this photo of a house and edit it to show the same house at night during the Christmas season, professionally lit with high-end Christmas lights. Keep the architecture, windows, doors, and roofline identical to the original photo. Add the following:

- Warm white C9 LED bulbs along every roofline edge, 12-inch spacing, evenly spaced. Lights should glow warmly, not blow out.
- Warm white C9 LED bulbs along all peaks, ridges, and dormers.

Add nothing else. No window outlines, wreaths, garland, bushes, trees, snow, or other decorations unless I list them.

Optional lines — include only the ones you actually want:
- A 48-inch lit wreath with a red bow on the front door, warm white mini lights on visible green greenery.
- The three bushes left of the porch draped in warm white mini lights, medium coverage.
- The evergreen in the front yard branch-wrapped in warm white mini lights.

The result should look like a professional photograph of the same house in early December at dusk, magical and inviting, taken with a high-quality camera. No text or watermarks.

Prompt 2: Roofline-only minimal package

For smaller starter packages.

Edit this photo of a house to show the same house at night during Christmas, with professional warm white C9 LED lights installed along every roofline edge with even 12-inch spacing. Include the gutter line and all peaks and dormers. Keep the architecture, windows, doors, and color of the house identical to the original. The lights should look professional, evenly spaced, and warmly glowing. Photographic style, early evening, no text or watermarks.

Prompt 3: Multi-color C9 (red, green, multi)

When the homeowner specifically asks for traditional multi-color or red-and-green.

Edit this photo of a house to show the same house at night during the Christmas season, professionally lit with multi-color C9 LED Christmas lights (red, green, blue, orange, white, pink) along every roofline, peak, and dormer with even 12-inch spacing. Bushes should be lit with warm white mini lights for contrast. Keep the architecture and color of the house identical to the original. Photographic, dusk, magical mood. No text or watermarks.

Same house, multi-color C9 mockup from Prompt 3.

Prompt 4: Commercial / HOA mockup

For HOA and commercial walkthroughs — rooflines, entry monuments, columns.

Edit this photo of a commercial building / HOA entry to show it professionally lit for Christmas. Add warm white C9 LED bulbs along every roofline edge with 12-inch spacing. Wrap any columns in warm white mini lights. Add lit garland with red bows above the main entrance. If there are entry monuments or stone walls in the photo, add subtle lit wreaths to them. Keep the architecture and signage identical to the original. Photographic style, dusk, professional and welcoming mood. No text.

Iterative edit prompts: how to fix what the first generation got wrong

Some first-pass mockups need one quick edit. The trick is to ask for the edit specifically and tell the AI what to keep:

  • Wreath too small. “Keep everything else identical but make the wreath on the front gable 60 inches (much larger) with a bigger red velvet bow.”
  • House color drifted. “Keep all the lights exactly as they are. Change the house siding back to the original gray color from my first photo.”
  • Lights too bright/blown out. “Same scene, but make the lights look softer and warmer, with a more subtle glow — like a real photograph taken at dusk.”
  • Bushes look wrong. “Keep the roofline and trees identical. Re-wrap the bushes with warm white mini lights at 6-inch spacing, more lights per bush, more even coverage.”
  • Need a darker sky. “Same image but later in the evening — deeper twilight sky, more contrast between the dark sky and the warm lights.”

Iterate two or three times max. If you can't get it close in four generations, the source photo is probably the problem — ask the homeowner for a clearer or wider photo.

Where the mockup actually goes (the workflow that converts)

The mockup is a tool, not the end product. Where it goes matters more than how pretty it is. Drop it into:

  1. The proposal email. Subject: “Here is what your house could look like this Christmas.” Image embedded above the line-item pricing. The image is what they see first; the price feels reasonable after.
  2. The text follow-up. After a phone call, text them the mockup with one line: “Just for fun — here is what we'd put together for the front of your house. Quote sent to your email.” Texts with images get 8x the response rate of plain text.
  3. The Instagram / Facebook DM. If they messaged you from social, mockup as the second reply (after the price-range question). Closes social leads dramatically faster.
  4. The walkthrough close. Even on in-person walkthroughs, generate the mockup before you knock on the door. Have it on your phone. Pull it up at the kitchen table. “Here's what we're putting together for you.” See our kitchen table close guide for the full sequence.
  5. The follow-up email a week later. If they ghost after the first proposal, re-send the mockup with one line: “Wanted to make sure this didn't get lost — spots are filling up for the week of [date], let me know if you want me to hold yours.”

The gear that lets the install actually look like the mockup

The mockup sells the magic. The gear delivers it. If the mockup shows warm white C9 LEDs at 12-inch spacing on the roofline, the install needs to match. Cheap big-box C9s won't — they get spotty within three weeks of cold weather and the homeowner's first reaction is “this looks nothing like the picture.”

Christmas Lights HQ stocks C9 LED bulbs with a 5-year warranty, Tuff Bulb clips and shingle tab clips, SPT-1 socket wire, Gilbert plugs, and pre-assembled Pro Light Kits ready to ship same-day before 2 PM ET. Free shipping on orders over $349. Use our Christmas light calculator to size any job. Shop the full catalog.

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FAQ

Does the homeowner need to send me a special kind of photo?

A daylight photo of the front of the house, taken from across the street or from the driveway, works great. Wider is better than closer — the AI needs to see the roofline, peaks, bushes, and trees. Cloudy days actually work better than bright sun (less shadow contrast for the AI to work around).

Should I tell the homeowner the mockup is AI-generated?

Yes, every time. Both for ethics and for trust. The label doesn't hurt the close rate — if anything, calling it a “quick AI mockup of your house” reinforces speed and modernity. Pretending the mockup is a real photo destroys trust the moment they realize it isn't.

Will AI mockups replace in-person walkthroughs?

Partially. They are replacing in-person walkthroughs for the smaller, simpler jobs — a clean roofline + a couple of bushes is a job a pro can quote online with an AI mockup in 20 minutes. In-person walkthroughs still win on complex rooflines, big tickets, HOA/commercial bids, and first-time customers who want to meet the contractor before they commit. The kitchen table close is still the highest-conversion move in the business — AI mockups are how you scale the rest of the funnel around it.

About the author

Jason Geiman is the founder of Christmas Lights HQ (wholesale Christmas light supplies) and ChristmasLights.io (43,000+ contractor community). He scaled a Christmas light installation business from $2,000 to $1M+ with four crews before selling in 2018, and now teaches the install playbook on the roof and in the classroom. Jason is a firefighter, ASE/EVT certified technician, EMT, and hazmat responder. The mockup workflow in this guide is the same one taught at Christmas Lights HQ training classes.