Every fall, homeowners start searching for the same answer: how many strands of Christmas lights does my house actually need? That math works fine for temporary lights you take down in January, but it does not carry over to permanent roofline lighting. A Trimlight system is not sold by the strand or the bulb count. It is measured in linear footage, with bulbs set at fixed intervals inside a patented channel that runs along your roofline. Because the bulbs are IP68 rated and stay installed year round rather than coming down after the holidays, the footage number you land on is closer to a long term specification than a seasonal decoration count, which is exactly why it is worth getting right before you request a quote.
This guide walks through how to measure your own roofline for a permanent lighting project, which of the three available node spacing options will look best on your home, and how to turn a finished footage number into a realistic project cost before you talk to a dealer.
Before you can put a number on your project, you need an accurate walk of your home's roofline, since not every homeowner lights every edge of the roof. Start by deciding which sections you actually want illuminated, typically the front facing eaves at minimum and often the side elevations if your home sits on a corner lot or has strong visibility from the street, then measure each straight run of roofline on its own rather than estimating a whole house total in one pass.
Run a tape measure or a measuring wheel along the bottom edge of the roofline where it meets the fascia, which is the same line a rain gutter typically follows. Measure each straight section separately and add the individual numbers together rather than pacing off the whole perimeter at once, since most homes have several distinct runs broken up by corners, porches, or garages rather than one continuous edge.
Corners themselves do not usually add extra footage, since the channel simply turns the corner and continues. Any break in the roofline is a different story. A dormer, a bump out, or a gable end that sits at a different height than the main eave line needs to be measured on its own, since the channel has to bridge that gap separately rather than running straight through it.
Peaks and gable ends are the section homeowners forget most often, especially the angled rake edges that climb up to the roof's high point. If your plan is to outline the full shape of your home rather than just the horizontal eaves, those angled runs need to be added to your total footage as their own line items, not folded into the eave measurement.
Multi story homes add another layer of difficulty here, since upper level rooflines are harder to measure accurately from the ground and often get estimated rather than actually measured. That single issue is one of the more common reasons a self measured total ends up short once a dealer takes a professional measurement of the whole home.
The two mistakes that throw off a footage estimate most often are measuring only the front of the home when side or rear sections will also be lit, and rounding a whole house perimeter instead of adding up each individual run. Both tend to undercount total footage, which is the direction you least want to be wrong in before placing an order.
Node spacing does not change your footage total, since that number comes from the physical length of your roofline. What it changes is how that footage actually looks once it is lit, and choosing between 6 inch, 9 inch, and 12 inch spacing has more to do with your home's size, architectural style, and how close up it is typically viewed than with anything on the measurement side. If you are still deciding whether permanent lighting fits your home at all, our guide to how permanent holiday lighting works covers the system beyond just measurements.
At 6 inch spacing, bulbs sit twice as close together as they do at 12 inch spacing, working out to roughly two bulbs per linear foot. That density creates a solid, continuous line of light rather than a series of individual points, which tends to look best on smaller to mid-size homes and on homes viewed up close, such as shorter front yards, tighter suburban lots, or homes set close to the street.
It also suits traditional architecture and homeowners who want their holiday display to read as bold and bright rather than understated, since the tighter spacing reads as a near-solid glow rather than a row of distinct points, even from a short distance away.
Nine inch spacing lands in between the other two options at roughly one and a third bulbs per foot, and it is the spacing most homeowners land on when they are not planning around one specific look. It reads as bright and well defined without the density of 6 inch spacing, which makes it a dependable default across a wide range of home sizes and architectural styles, from a mid-size ranch to a two-story colonial.
Twelve inch spacing works out to a single bulb per linear foot, creating the most defined, spaced-out line of the three options rather than a continuous glow. On a large home with a long roofline, that spacing reads as clean and intentional rather than sparse, since there is more roofline for the eye to travel across between each point of light.
It also tends to suit modern or minimalist architecture, where a cleaner line complements the home's design better than maximum brightness would, along with homes that are typically viewed from farther back, such as long driveways, larger lots, or homes set well off the street.
The tradeoff runs the opposite direction from 6 inch spacing. A home viewed up close, or a homeowner who wants their display to be the brightest one on the block, will usually find 12 inch spacing reads as a bit sparse compared to the other two options, so it is worth weighing viewing distance alongside home size before settling on it.
With a footage number and a node spacing preference in hand, you have what you need to build a realistic budget range before requesting a quote. Trimlight roofline systems typically run $18 to $35 per linear foot installed, and multiplying that range by your total footage gives you a workable estimate for planning purposes, even before a dealer confirms the final number.
Several factors move a project up or down within that per foot range beyond footage alone. Bulb choice plays a role, since Classic single LED bulbs and 3L triple LED bulbs are priced differently from each other, and node spacing can factor in as well, given how much it changes the total bulb count installed along the same length of channel.
Installation complexity matters just as much. A single story home with a few simple eave runs typically installs faster than a multi story home with several rooflines, dormers, and gable ends to bridge, and that difference in labor time shows up in the final quote even though the system itself is priced per linear foot. For a full look at what drives cost beyond footage alone, Trimlight's pricing guide breaks down each of these factors in more depth.
A self measured estimate is useful for budgeting, but it is still an estimate. Trimlight has been building permanent lighting systems since 2010, and that experience is exactly why a professional measurement from one of its more than 300 authorized dealers nationwide is worth the extra step before installation. That visit also confirms your labor warranty, since Trimlight backs the system itself with a lifetime parts warranty while authorized dealers separately provide a minimum one year labor warranty on the installation.
Raw measurements get you close, but it is worth thinking beyond the exact number before you finalize anything. A small cushion for corners and connections, along with a bit of forward thinking about anything you might want to add down the road, keeps your footage total realistic rather than a bare minimum that leaves no room for adjustment once a dealer takes their own measurement.
Any linear system installed along a roofline needs a bit of material beyond the exact distance between two points, since corners, seams, and small gaps between your number and an installer's number are normal rather than a sign something went wrong. Treating your self measured total as a close estimate rather than a locked in figure keeps expectations realistic heading into a quote.
This is also where a professional measurement earns its keep. A dealer walking your roofline in person accounts for the same corners and connections you measured, but with the experience to know how much material a given run actually needs, which is part of why a final invoice can land slightly above or below a homeowner's own tape measure total.
Some homeowners start with just the front eaves and later decide to light a garage, a fence line, or a detached structure once they see how the system looks year round. If there is any chance you will want to expand later, mention that to your dealer up front, since planning the initial run with future additions in mind is often simpler than treating each expansion as a separate project down the line.
Most single story homes need 100 to 150 linear feet of roofline lighting, while larger or multi story homes often require 200 feet or more depending on layout.
Node spacing is the fixed interval, 6, 9, or 12 inches, at which bulbs sit inside the channel, and it determines how many bulbs are installed along your measured footage.
Yes. Node spacing is one of several factors that can affect where a project lands within the $18 to $35 per linear foot range, alongside home size and installation complexity.
Most residential roofline projects total $2,000 to $6,000 or more, based on total footage, node spacing, and bulb type.
No, permanent roofline systems are measured in continuous linear footage rather than individual strand counts, since bulbs sit inside a fixed channel instead of clipped strands.