Artificial turf along the side of the house: foundation clearance, window wells, downspouts and the builder’s swale

01Is a narrow side yard a good place for artificial turf?

Often. CSU Extension says strips of grass narrower than 8 feet are hard to water well with spray heads (CSU Extension), and on expansive soils it says to keep sprinkler spray at least five feet from the foundation (CSU PlantTalk). In a narrow side yard those two rules cover nearly all the ground. Turf needs no spray.

Many side yards are that narrow: Firestone’s zoning table lets a single-family house sit as close as 5 feet to an interior side lot line (Table 4-1), so two neighbors’ walls can stand about 10 feet apart.

02What is the builder’s swale, and how does turf keep it working?

The 2021 International Residential Code wants the ground to fall at least 6 inches in the first 10 feet from a house. Two houses 10 feet apart can’t both get that, so the code adds: where “lot lines, walls, slopes or other physical barriers” prevent the fall, “drains or swales shall be constructed” (IRC R401.3). The side-yard swale is that shallow valley between the walls, carrying water from both roofs to the street or the back of the lot. Windsor’s drainage criteria require subdivision plans to show swales, “including side/rear yard swales,” with their cross-sections (Town of Windsor). Towns adopt their own code editions; ask yours which applies.

Turf sits on the swale; it doesn’t replace it. Firestone’s code says the lot’s drainage pattern “shall not be impeded or altered by the installation of artificial turf” (Firestone Development Code 16.6.4), and Frederick’s bars landscaping, “including any artificial turf,” from changing the pattern or runoff in the approved grading plan (Frederick Land Use Code). On the ground:

• The dig follows the swale, so its low line stays low and runs unbroken to where the builder sent it.
• Nothing crosses the flow line. The Colorado Geological Survey counts patios, fences and “other obstructions that dam and pond water” among homeowner mistakes on swelling soil (CGS SP-14). An edging board laid across a swale is one.
• The neighbor stays dry. The same guide says water carried off one house must not be “directed against a neighboring structure,” which in a side yard stands a few feet away.

Reading a grading plan: new-build backyard turf.

03How close can turf come to the foundation and siding?

It can meet the wall. Two things decide whether it should.

Height. A base and turf can raise the finished ground at the wall, and building code keeps a gap there:

Measure the gap before anyone digs, and keep it: a higher grade at the wall isn’t the answer.

Water. The Colorado Geological Survey lists poor surface drainage, and planting by foundations so irrigation water soaks in, among landscaping problems on expansive soils (CGS). Turf removes the sprinkler. But turf and its porous base pass water down, and CGS’s advice for the band beside a house runs the other way: gravel over non-woven fabric, at least 5 feet out, the fabric lapped onto the foundation, “to prevent percolation of water into the soils next to the foundation.” Turf tight to the wall works only when the ground under the base falls away from the house, as R401.3 asks, so water leaves instead of soaking in at the footing.

In a 5-foot side yard, that edging is the whole yard. On some lots the honest layout is rock along the house and turf where the yard opens up; turf, pavers or concrete compares hard surfaces. On a newer house the backfill is still settling.

04What about window wells, downspouts and the air conditioner?

Window wells. An egress window well must be at least 9 square feet, reach 36 inches out, and drain into the foundation drain unless the house sits on well-drained sand or gravel (IRC R310.4). Clay isn’t that, so water that gets into a well on a clay lot ends up at the footing drain. Keep the rim above the finished turf, with the ground falling away from it. A cover must open from inside without a key or tool.

Downspouts. CGS says downspouts should carry roof runoff at least 10 feet from the house (CGS SP-11), and CSU Extension warns against pulling extensions off to water beds by the house. Ten feet straight out can hit the neighbor’s wall, so the extension turns and runs down the swale. If it goes under the turf, ask how it gets cleaned out.

Condenser, meters and hose bib. Leave them reachable, with firm footing for service. The condenser’s installation manual gives its clearance.

05Do town rules and HOAs allow turf in a side yard?

Some don’t. Not legal advice.

Firestone’s buffer decides narrow lots. Beside a house 5 feet from the side lot line, a 3-foot planted strip at the line leaves about 2 feet, so in many Firestone side yards the space goes to plants. That’s arithmetic on the code, not a Town ruling: the code measures a side yard from the house to the side lot line (16.11.3), and how the Town applies both rules depends on your plan, so ask Firestone Planning. In Greeley it depends on the lot and when it was developed: ask Greeley Planning.

State law helps less than it seems. Colorado’s SB23-178 bars an HOA from prohibiting turf in the backyard of a detached home and makes special-district rules that do so unenforceable. The turf clause names only the backyard; the clause beside it protects vegetable gardens in the “front, back, or side yard.” Whether your side yard counts depends on your community’s documents: ask the HOA in writing before you build, and a Colorado attorney if it becomes a dispute. More in HOA approval for artificial turf and artificial turf rules in Northern Colorado.

06What else does a strip between two houses ask of turf?

• Reflected heat. NAHB says closeness to a neighboring structure is a factor in damage from sunlight reflected off Low-E windows; a builders’ survey found most siding damage within 30 feet of the window (NAHB). A side yard sits well inside that.
• Shade and snow. A north side yard holds both longest: see turf in a shady, north-facing yard.
• Dogs. Some communities send dog runs here: Timnath Lakes puts a run in the rear or side yard, against the home (Timnath Lakes rules). A potty strip along the wall puts rinse water beside the foundation, where CSU says water should be carefully regulated. Rinse toward the swale; see pet turf.
• Access. Toro sells a narrow-track loader under 35 inches wide, made for a standard 36-inch gate (Toro). Measure your gate; see getting ready for install day.

07What should I ask before turf goes in along the house?

• “Where does water go after it passes through the turf?” A good answer names the swale’s low line and the outlet the builder’s plan uses, with the ground under the base falling away from the house.
• “How much will the finished turf raise the ground at the wall?” A good answer comes after they’ve measured the siding or weep-screed gap, and keeps it at code.
• “What happens at the window wells and downspouts?” Rims stay above the turf; extensions stay on and discharge down the swale.
• “Does my town or HOA allow turf in this side yard, and who files?” In Firestone that includes the permit and the 3-foot buffer.

More in questions to ask a turf installer and on the artificial turf installation page.