--- title: "How Close Can Turf Go to Your House? | TIMELESS Grass & Greens" description: "Where turf should stop along the foundation: the 6-inch fall rule, foundation and siding clearance, gravel strips on Colorado clay and Thornton's buffers." url: https://www.timelessgrass.com/blog/artificial-turf-next-to-the-house/ updated: 2026-09-12 --- Lawns # How close can artificial turf go to your house? * * * Updated 2026-09-12 The short answer ## How close can artificial turf go to your house? The building code sections we read set no distance for turf. They set the ground instead. It has to fall at least 6 inches in the first 10 feet, and the foundation still has to show above it. On Front Range swelling clay, the Colorado Geological Survey describes a gravel edging at least 5 feet wide as a way to keep water out of the soil by the house. Some towns add a buffer, including Thornton. Planning a turf installation? Get a layout, turf options and a written quote for your space. [Request a free estimate](https://www.timelessgrass.com/estimate/?use=Lawn) [Call 303-349-2368](tel:3033492368) We’ll call to arrange a free site visit. On this page On this page 1. [The code sets the slope, not a distance](https://www.timelessgrass.com/blog/artificial-turf-next-to-the-house/#the-code-sets-the-slope-not-a-distance) 2. [Keep the foundation showing above the turf](https://www.timelessgrass.com/blog/artificial-turf-next-to-the-house/#keep-the-foundation-showing-above-the-turf) 3. [On swelling clay, give the wall a gravel strip](https://www.timelessgrass.com/blog/artificial-turf-next-to-the-house/#on-swelling-clay-give-the-wall-a-gravel-strip) 4. [Slope more than the minimum, and check it again](https://www.timelessgrass.com/blog/artificial-turf-next-to-the-house/#slope-more-than-the-minimum-and-check-it-again) 5. [Send the downspouts past the turf edge](https://www.timelessgrass.com/blog/artificial-turf-next-to-the-house/#send-the-downspouts-past-the-turf-edge) 6. [Thornton writes the buffer into its rules](https://www.timelessgrass.com/blog/artificial-turf-next-to-the-house/#thornton-writes-the-buffer-into-its-rules) 7. [Before you draw the turf line](https://www.timelessgrass.com/blog/artificial-turf-next-to-the-house/#before-you-draw-the-turf-line) ## The code sets the slope, not a distance The model residential code doesn’t say how far turf has to stay from a wall. It says what the ground next to the wall has to do, and turf sits on that ground. Section R401.3 of the 2021 International Residential Code (IRC) says lots “shall be graded to drain surface water away from foundation walls.” The grade has to fall at least 6 inches within the first 10 feet ([IRC R401.3](https://up.codes/viewer/colorado/irc-2021/chapter/4/foundations)). Two follow-ups sit in the same section: - **Where a lot line, wall or slope blocks that fall,** drains or swales have to carry the water away instead. - **Hard surfaces within 10 feet of the foundation,** such as a paver path, must slope at least 2 percent away from the building. So turf can run toward the house, as long as the base under it keeps that fall. Which code edition applies depends on your address, so ask your building department. ## Keep the foundation showing above the turf Turf adds height. Thornton’s rules, for example, call for a sub-base at least three inches deep of compacted aggregate, with the turf on top ([Thornton Water](https://www.thorntonwater.com/wp-content/uploads/2026/02/2026-residential_artificial_turf_info__rules-1.pdf)). Stack those layers on the old soil by the wall, and the ground against your house comes up. Two code sections are worth measuring against: - **Foundation height.** Concrete and masonry foundation walls must extend at least 6 inches above the finished grade beside them, or 4 inches where masonry veneer is used (IRC R404.1.6). - **Wood siding.** Wood siding, sheathing and wall framing with less than 6 inches of clearance from the ground, or less than 2 inches above a patio slab or step, must be naturally durable or preservative-treated wood ([IRC R317.1](https://up.codes/viewer/colorado/irc-2021/chapter/3/building-planning)). The code doesn’t mention turf, so ask your building department how it measures finished grade. A layout that keeps those clearances usually means digging the base in, not stacking it on top. ## On swelling clay, give the wall a gravel strip All major population centers on Colorado’s Eastern Slope sit partly on potentially swelling soils, according to the Colorado Geological Survey. Its [expansive soil page](https://coloradogeologicalsurvey.org/hazards/expansive-soil-rock/) names a common landscaping mistake: planting next to the foundation “so irrigation water enters the soil.” Turf is built to let water through. Thornton’s rules require backing that drains at least two inches an hour. In the middle of the yard, that’s the point. Against a wall on swelling clay, it sends rain and snowmelt into the strip of soil you most want to keep dry. The Survey’s homeowner guide, Special Publication 14 (1981, revised 1987), gives the alternative. It says gravel edging over fabric can “prevent percolation of water into the soils next to the foundation” ([CGS SP-14](https://coloradogeologicalsurvey.org/wp-content/uploads/woocommerce_uploads/SP-14.pdf)). The details: - **At least 5 feet wide,** measured out from the house. - **Non-woven geotextile fabric** underneath, lapped onto the foundation wall and glued in place. - **No plastic sheeting.** The guide discourages it because it traps moisture and stops normal evaporation. - **A path across it.** Walking on the rock damages the fabric, and worn-out fabric lets weeds and water back in. The same guide draws two more 5-foot lines. Sprinklers shouldn’t spray closer than 5 feet from the foundation. Flowers and shrubs stay at least 5 feet away unless they need very little water and are watered by hand. One of its illustrations is a central lawn accented by gravel edging. Swap the lawn for turf and you have the layout. Where wildfire is a risk, that first 5 feet has a second reason to be gravel or pavers, covered in [can artificial turf catch fire?](https://www.timelessgrass.com/blog/can-artificial-turf-catch-fire/) ## Slope more than the minimum, and check it again On swelling soil, the Survey asks for more fall than the code. SP-14 sets a 5 percent minimum for planted areas and recommends 10 percent within the first 10 feet of a foundation. That’s 12 inches of drop. It doesn’t recommend slopes steeper than 15 percent. The ground by a newer house also moves. Soil backfilled around a foundation settles during the first months or years. SP-14 says that settlement is often enough to flatten or reverse the slope next to the house. So check the fall before the base goes in, not after. ## Send the downspouts past the turf edge A downspout that empties onto turf by the wall undoes the strip. Where expansive soils are known to exist, the code requires roof water to discharge at least 5 feet from foundation walls, or into an approved drainage system ([IRC R801.3](https://up.codes/viewer/colorado/irc-2021/chapter/8/roof-ceiling-construction)). SP-14 sets the same 5 feet and says you’ll usually need a downspout extension to get there. Watch the edges too. SP-14 counts patios, fences and other obstructions “that dam and pond water” among the ways a lot’s drainage gets changed. Any edging along the turf should let water cross it, away from the house. ## Thornton writes the buffer into its rules Thornton sets a distance. Its artificial turf rules, dated 1 January 2026, require a Minor Development Permit before turf goes in. They also set minimum buffers from the edge of the turf: - **Buildings.** 8 feet from the front wall of any building, and 3 feet from other building walls or impervious surfaces, for turf outside the rear or an enclosed side yard. - **Property lines.** 3 feet. Turf may reach the front property line if a 3-foot buffer separates it from the street sidewalk. - **Trees.** 3 feet from a deciduous trunk, and no closer than an evergreen’s dripline. The buffer has to be permeable: wood mulch, gravel, rock no more than two inches across, or another approved permeable material. The rules point back to the city’s landscape code, so confirm with Thornton’s planning department before you set the line. There’s more on the city on our [Thornton page](https://www.timelessgrass.com/denver-metro/thornton-co/). Other towns and HOAs can set their own limits. Check yours before the layout is final. ## Before you draw the turf line 1. **Measure the fall.** Drive a stake at the wall and another 10 feet out, and run a level string between them. The code wants at least 6 inches of drop. On swelling clay, the Survey recommends 12. 2. **Measure what’s showing.** Note how much foundation shows above the soil, and the gap under any wood siding. 3. **Set the base depth** so at least 6 inches of foundation still shows above the finished turf, or 4 with masonry veneer. 4. **On clay, mark a gravel strip** at least 5 feet wide, over non-woven fabric, not plastic. 5. **Move the water.** Sprinklers stop 5 feet short of the wall. Downspouts discharge at least 5 feet out. 6. **Check local buffers and permits,** in Thornton and wherever your town or HOA sets one. On the free visit we measure the space and check the ground, including the fall along the house. Then we draw a custom layout for you to approve, with the line where the turf stops marked on it. ## Common questions ### Can artificial turf go right up against the house? The code sections we read don't forbid it, but they set conditions. The ground has to fall at least 6 inches in the first 10 feet, and concrete or masonry foundation walls have to show at least 6 inches above the finished grade, or 4 inches with masonry veneer ([IRC R401.3 and R404.1.6](https://up.codes/viewer/colorado/irc-2021/chapter/4/foundations)). On Colorado swelling clay, the state's geological survey points to a gravel edging against the wall instead. ### How wide should the gravel strip be? On swelling soil, the [Colorado Geological Survey](https://coloradogeologicalsurvey.org/wp-content/uploads/woocommerce_uploads/SP-14.pdf) says gravel edging should extend at least 5 feet out from the house, over non-woven geotextile fabric lapped onto the foundation wall and glued in place. It discourages plastic sheeting because it traps moisture. A town can also set its own buffer, so check local rules too. ### Where should downspouts drain if turf runs along the house? Past the turf edge, not onto it. Where expansive soils are known to exist, [IRC R801.3](https://up.codes/viewer/colorado/irc-2021/chapter/8/roof-ceiling-construction) requires roof water to discharge at least 5 feet from foundation walls, or into an approved drainage system. The Colorado Geological Survey adds that you usually need a downspout extension to reach that far. ### What does Thornton require between turf and a building? Its 2026 turf rules set a buffer of 8 feet from the front wall of any building and 3 feet from other building walls or impervious surfaces, for turf outside the rear or an enclosed side yard ([Thornton Water](https://www.thorntonwater.com/wp-content/uploads/2026/02/2026-residential_artificial_turf_info__rules-1.pdf)). The buffer must be permeable, such as wood mulch or gravel. A Minor Development Permit comes first, so confirm the details with the city's planning department. ### Does the top of the turf count as the finished grade? The code text doesn't mention artificial turf, so it doesn't say. Ask your building department how it measures. The simple way to stay clear of the question is to plan the base depth so the foundation clearance holds when you measure from the top of the turf. ## Related turf questions - [Can you put artificial turf on a slope?](https://www.timelessgrass.com/blog/artificial-turf-on-a-slope/) - [Can you lay artificial turf over a concrete patio?](https://www.timelessgrass.com/blog/artificial-turf-over-a-concrete-patio/) - [Artificial turf or xeriscape for a Denver yard?](https://www.timelessgrass.com/blog/artificial-turf-vs-xeriscape-denver/) ## Where to go next - [Artificial lawns](https://www.timelessgrass.com/services/residential-turf/) - [Turf in Denver Metro](https://www.timelessgrass.com/denver-metro/) - [Does artificial turf count as an impervious surface?](https://www.timelessgrass.com/guides/is-artificial-turf-impervious/) Useful links - [UpCodes: 2021 International Residential Code, Chapter 4 Foundations (R401.3 drainage, R404.1.6 height above finished grade), as adopted without amendments in the Colorado DFPC Residential Code 2021](https://up.codes/viewer/colorado/irc-2021/chapter/4/foundations) - [Colorado Geological Survey: Expansive Soil and Rock](https://coloradogeologicalsurvey.org/hazards/expansive-soil-rock/) - [Thornton Water: 2026 Artificial Turf Rules for Water-Wise Landscape Rebate (dated 1 January 2026), buffering and installation](https://www.thorntonwater.com/wp-content/uploads/2026/02/2026-residential_artificial_turf_info__rules-1.pdf) Free estimate ## Planning a turf installation? Tell us about the area you want to install or replace. We’ll call to arrange a free site visit. [Or call 303-349-2368](tel:3033492368) Your free estimate includes - A visit to measure your space - A custom layout, drawn for your space - Turf options, side by side - A written price, with no pressure to sign [Request a free estimate](https://www.timelessgrass.com/estimate/) Five short steps. We’ll call to arrange your visit.