Generator clearances: how far from the house, by manufacturer

Checklist

• Check local codes first: Generac says they take precedence over its clearance recommendations.
• Generac says its home standby generators are not designed or intended for a secondary enclosure, and it does not recommend covers or enclosures.
• Generac's installation documents give a distance only for a removable barrier without footings, a visual surround: fence panels at least 3 ft (0.91 m) from the generator, or in front of it in the PowerPact and 2022 Guardian guidelines. For walls and fences in general, the Protector and XG guidelines only say to consider their proximity to airflow.
• Keep shrubs and trees out of the 3 ft zone at the front and ends, and do not hide the unit with plants (Generac, Briggs & Stratton).
• Leave 5 ft clear above the unit and keep it out from under a deck (Generac, Briggs & Stratton, Champion).
• Windows, doors and vents: 5 ft in the Briggs & Stratton manual; Champion's manual says 5 ft from windows and vents and its Help Center article adds doors; 5 ft from the exhaust end on Kohler drawings; local code in Generac's tables.
• Portable generator: outside only, at least 20 feet from the house, not on a porch or in a carport (CPSC).

Each point is explained below with its source: the manual page or the government agency.

A home standby generator is installed outdoors, at distances its manufacturer prints in the installation manual: from the house wall, from windows, doors and vents, from anything overhead, and from shrubs and fences (Generac 10–28 kW installation manual, pp. 5, 18–19; Kohler TP-6803, pp. 11–12). The numbers differ by brand, series and revision, and the manuals defer to state and local codes, so each figure below comes with its document and page. None of the documents we read gives dimensions for a shed or box built around a standby unit; for a portable generator the distance comes from federal agencies, and CPSC says at least 20 feet from the house.

Standby generators

Generac’s Help Center article on clearance requirements says: “Always check local codes, as those will take precedence over these recommendations.” Kohler: “The required distance from a structure is dependent on state and local codes” (Kohler TP-6803, p. 12; Kohler TP-7091, p. 17). Champion: “Local codes may be different and more restrictive” (Champion aXis installation manual, p. 19).

Generac writes that its clearances are “primarily for fire prevention, but also to provide sufficient room for removing front and end panels for maintenance purposes” (Generac 10–28 kW installation manual, p. 18). The table gives each document’s own numbers, with a separate row wherever a series differs. “Shown on the drawing” marks a number read from a Kohler dimension drawing; those drawings do not say in words which side of the unit a wall distance applies to.

Model and document	House wall	Windows, doors, vents	Overhead	Front, ends, service	Shrubs and fences
Generac Next Generation 10–28 kW and Guardian 10–26 kW, air-cooled (Generac 10–28 kW installation manual, pp. 18–19; Generac Guardian 10–26 kW installation guidelines, pp. 15–16)	Rear: 18 in. (457 mm). Existing walls: the generator should not be placed closer than locally adopted codes permit	None closer to any point of the generator than locally adopted codes permit; no number	Structures, overhangs and projections at least 5 ft (1.52 m) above the top of the unit, also above the front, end and rear zones	3 ft (0.91 m)	The 3 ft and 18 in. zones include shrubs, bushes and trees. Removable fence panels cannot be placed within 3 ft (0.91 m). Do not attempt to conceal the generator with shrubs, bushes or plants
Generac PowerPact 7.5 kW (Generac PowerPact installation guidelines, p. 13)	Rear: 18 in. (457 mm) “per SwRI testing, labeling, and listing, unless state or local codes dictate otherwise”. Existing walls: the generator should not be placed closer than locally adopted codes permit	None closer than locally adopted codes permit; no number	5 ft (1.52 m) from any structure, overhang or projection from a wall	3 ft (0.91 m)	The 3 ft zone includes shrubs, bushes and trees. Removable fence panels for servicing cannot be placed less than 3 ft (0.91 m) in front of the generator. Do not attempt to conceal it with plants
Generac Protector, liquid-cooled (Generac Protector installation guidelines, pp. 11–12)	Rear, no SwRI on the data plate: 5 ft (1.52 m) if the wall is not fire rated, 3 ft (0.91 m) if it is one-hour fire rated. SwRI on the data plate: 18 in. from a combustible wall	None closer than locally adopted codes permit; no number	At least 5 ft (1.52 m) above the top of the unit, also above the front, end and rear zones	3 ft (0.91 m)	The 3 ft zone includes shrubs, bushes and trees. Removable fence panels cannot be placed within 3 ft (0.91 m). Do not attempt to conceal it with plants
Kohler 14RESA, 14RESAL, 20RESC, 20RESCL (Kohler TP-6803, pp. 12, 55, 59)	Shown on the drawing: combustible wall 5 ft; non-combustible wall 18 in. minimum, 3 ft recommended	Shown on the drawing, among the conditions listed as acceptable: nearest window, vent, door or similar opening at least 5 ft from the exhaust end, and windows and doors on adjacent walls closed. Furnace and similar intakes at least 10 ft (3 m) from the exhaust end	No number found	No number; the location “must allow easy access for maintenance and service”. 4 ft clearance at the exhaust end	No plants, shrubs or other combustible materials within 4 ft (1.2 m) of the exhaust end. Shown on the drawing: none within 18 in. of the air intake. No fence wording found
Kohler 14RCA, 14RCAL, 20RCA, 20RCAL (Kohler TP-7091, pp. 17, 65)	Shown on the drawing: 30 in. minimum and 18 in. minimum	Shown on the drawing: nearest window, vent, door or similar opening at least 5 ft from the exhaust end, and windows and doors on adjacent walls closed. Furnace and similar intakes at least 10 ft (3 m) from the exhaust end	No number found	No number; the location “must allow easy access for maintenance and service”. 4 ft clearance at the exhaust end	None within 4 ft (1.2 m) of the exhaust end. Shown on the drawing: none within 30 in. of the air intake. No fence wording found
Kohler 26RCA (Kohler TP-7091, pp. 17, 70)	Shown on the drawing: 30 in. minimum and 18 in. minimum	As for the 14RCA and 20RCA	Shown on the drawing: “OVERHANGS AND AWNINGS MUST BE A MINIMUM OF 5 FEET FROM GENSET”	Shown on the drawing: “MUST MAINTAIN A MINIMUM OF 3 FEET CLEARANCE FROM SERVICE DOOR ENTRANCE”. 4 ft clearance at the exhaust end	As for the 14RCA and 20RCA
Briggs & Stratton 17–26 kW, PowerProtect (Briggs & Stratton 17–26 kW manual, pp. 8–9)	At least 18 in. (45.7 cm) from existing walls. Back: 18 in. “per independent testing laboratory, unless state codes tell you otherwise”	At least 5 ft (1.52 m) from all windows, doors, vents, window wells or openings in the wall. HVAC supply air intakes 10 ft (3 m) horizontally from the enclosure	5 ft (1.52 m) from all structures, overhangs, projections on a wall, or trees	3 ft (.91 m)	Shrubs, bushes, plants and trees 3 ft from the front and ends; “never use vegetation to conceal the unit”. Removable fences at least 3 ft (.91 m) from the front
Champion aXis 14 kW, model 100515 (Champion aXis installation manual, pp. 19, 21)	17.7 in. (45 cm) from the back of the generator to a combustible wall	Minimum 5 ft from any windows. Avoid installing within 5 ft (1.5 m) of a home vent, roof overhang vents or a window that can be opened	Minimum 5 ft vertical clearance	18 in. (1.5 ft) for door clearance; minimum 5 ft beyond the exhaust end	No fence or screen wording
Champion aXis 22 kW, model 100304 (Champion aXis installation manual, pp. 19, 21)	17.7 in. (45 cm) from the back of the generator to a combustible wall	As for the 14 kW	Minimum 5 ft vertical clearance	36 in. (3 ft) at the alternator end and 18 in. (1.5 ft) for door clearance; minimum 5 ft beyond the exhaust end	No fence or screen wording

Generac’s 18 in. at the rear is a reduced distance. The manual says that, based on testing by SwRI and on NFPA 37, Sec 4.1.4, its guidelines were changed to 18 in. (457 mm) from the back and 3 ft (0.91 m) from the front and ends “to a structure having combustible walls”, and that this reduction does not apply to unprotected openings in the structure or to protected openings with a fire resistance rating of less than 1 hour (Generac 10–28 kW installation manual, p. 20). The Help Center article on clearance requirements narrows it further: “Reduced clearance distances based on testing by the Southwest Research Institute (SwRI) apply only to generator models marked with the SwRI logo.” Units without the logo, the same article says, “must be installed 5 ft. from combustible materials and 3 ft. from non-combustible materials.” The Protector table ties the rear distance to the SwRI mark on the data plate in the same way.

Generac’s distance tables give no number for windows, doors and vents. The 5 ft figure appears in two other places. One is Generac’s description of NFPA 37 in the same manual, which it says limits an engine generator “to a minimum of 5 ft (1.5 m) from an opening in a structure or a structure having combustible walls” (Generac 10–28 kW installation manual, p. 19). The other is a list in the Help Center article on clearance requirements, introduced as NFPA 37 requirements: 5 ft from openings in walls, 18 in. from the back of the generator to a wall (based on SwRI testing), 5 ft above the generator, 3 ft at the front and both ends. That article also says: “Refer to your generator’s installation manual for the most up-to-date information.” Generac’s Help Center article on operable windows says Generac does not recommend installing a generator near any operable windows, doors, vents, window wells or openings in the wall; it gives no number and says to consult local codes.

The window wording changed between Generac revisions. The Guardian guidelines of May 2025 and the PowerPact guidelines say “No operable windows, doors, vents, window wells, or openings in the wall”; the Next Generation manual of April 2026 and the Guardian site selection sheet of June 2026 say “No windows” (Generac Guardian 10–26 kW installation guidelines, p. 15; Generac PowerPact installation guidelines, p. 13; Generac 10–28 kW installation manual, p. 19; Generac Guardian site selection sheet, p. 3). Generac’s list of CO entry points counts windows and doors “including inoperable windows or doors” (Generac 10–28 kW installation manual, p. 17). The older Guardian guidelines, Rev. B of April 2022, put a number on the wall instead: “The generator should not be placed closer than 18 in (457 mm) from existing walls.” They permit no operable windows, doors, vents, window wells or openings in the wall “near any point of the generator”, and give no distance for them (Generac 10–24 kW installation guidelines, Rev. B, p. 15).

Generac’s larger liquid-cooled XG series, 25 to 80 kW, sets its distances by side of the enclosure and permits no structure, overhang or projection above the unit or above the 3 ft (0.91 m) clearance at its service side or discharge end (Generac XG installation manual, pp. 17–18).

Two shorter manufacturer articles give numbers that differ from the manuals. Briggs & Stratton’s location article (June 28, 2024) gives a minimum of 48 inches at the top, where the 17–26 kW manual gives 5 ft (1.52 m), and adds that generators should generally be placed away from shrubs or vegetation over 12 inches in height. Champion’s Help Center placement article says “The unit should be installed no less than 18 inches from the home”, where the installation manual gives 17.7 in., and puts doors, windows and other openings at a minimum of five feet.

Kohler’s drawings explain their wall numbers in notes. On the RES drawings, note 1 reads “THE RECOMMENDED DISTANCE FROM A STRUCTURE IS DEPENDENT ON STATE AND LOCAL CODES” and says NFPA 37 “STATES THIS DISTANCE SHOULD BE AT LEAST 5 FEET FROM A COMBUSTIBLE MATERIAL”; note 2 requires a minimum distance of 18 in. near a non-combustible structure “TO ENSURE PROPER GENERATOR COOLING” (Kohler TP-6803, pp. 55, 59). The RCA drawing says instead that the product “HAS BEEN DEMONSTRATED IN ACCORANCE [sic] WITH NFPA 37 SECTION 4.1.4 BY A THIRD PARTY TEST FACILITY TO THE DIMENSIONS SHOWN” (Kohler TP-7091, p. 65). On all four drawings, the list of acceptable conditions starts with an exhaust “AIMED AWAY OR PARALLEL TO STRUCTURE” and not directed at play areas, patios or other areas where people congregate (Kohler TP-6803, pp. 55, 59; Kohler TP-7091, pp. 65, 70).

What the manuals say about NFPA 37

All four manufacturers refer to NFPA 37, which Generac describes as the National Fire Protection Association’s standard for the installation and use of stationary combustion engines. Generac’s manual says generator installation “must comply strictly with ICC IFGC, NFPA 37, NFPA 54, NFPA 58, and NFPA 70 standards” and that these standards prescribe the minimum safe clearances around and above the enclosure (Generac 10–28 kW installation manual, p. 19). Briggs & Stratton and Champion print their own versions of Section 4.1.4, Engines Located Outdoors: 5 ft from openings in walls and from structures with combustible walls, with no minimum separation required where the adjacent wall has a fire resistance rating of at least one hour (Briggs & Stratton 17–26 kW manual, p. 6; Champion aXis installation manual, p. 19). Generac’s summary names one exception: approved testing that shows a fire starting at the engine does not ignite the combustible structure (Generac 10–28 kW installation manual, p. 19). A CPSC staff report notes that the minimum distances in manufacturers’ installation instructions “are obtained from NFPA 37” (CPSC staff report, p. 2).

We did not read NFPA 37 itself. This page repeats only what the manuals and the CPSC staff report say about it.

Carbon monoxide and where the exhaust goes

Generac’s manual warns that a unit placed by the NFPA requirements, “including the offset reduction validated through testing by SwRI, may still allow CO within the structure”, and that the unit “may need to be installed farther from the structure than the NFPA requirements” (Generac 10–28 kW installation manual, p. 16). Its table of CO entry points near the house lists windows and doors, garage doors that are open or do not seal, attic, ridge and soffit vents, basement windows and crawl spaces, furnace intake and exhaust pipes, and dryer vents. Corners, alcoves, fences, courtyards and areas with heavy vegetation are on it too, because they can restrict airflow around the unit: “Exhaust gases can be collected in these areas” (p. 17). The manual says not to direct generator discharge into HVAC components, including make-up air systems, AC condensers and window AC units (p. 18). The Next Generation owner’s manual says outdoor air intake openings for air distribution and supply systems must be located not less than 10 ft (3.05 m) horizontally from the generator enclosure (Generac 10–28 kW owner’s manual, p. 18).

The other three brands say where to point the exhaust. Kohler: do not install the set “where exhaust gas could accumulate and seep inside or be drawn into a potentially occupied building”, and locate it so the hot exhaust does not blow on plants or other combustible materials (Kohler TP-6803, p. 12). Champion: “Direct the HSB exhaust away from or parallel to the building or structure”, and use the same precautions at a property line, close to a neighbor’s home, or near any building or structure that houses animals (Champion aXis installation manual, p. 21). Briggs & Stratton says to direct exhaust away from windows, doors, ventilation intakes, soffit vents, crawl spaces and open garage doors, and: “Never expose your neighbors’ homes to the engine exhaust flowing from your standby generator during the installation process” (Briggs & Stratton 17–26 kW manual, pp. 5, 7).

A CPSC staff report on stationary generators, dated June 3, 2025, describes what happened after Hurricane Ida in the New Orleans area, where CO from stationary generator exhaust got into many homes. The data show exhaust that “had traveled at least 25 feet away from the enclosure”, spread at least 6 feet sideways and rose more than 10 feet, high enough indoors to set off the homes’ CO alarms (CPSC staff report, p. 2). At one home, a brick wall at least a few feet from the exhaust side deflected the exhaust upward, 15 to 20 feet, to second-floor windows and the soffit vents above them (p. 25). Staff concludes that the 5 ft enclosure-to-opening clearance allowed in NFPA 37 is inadequate and recommends that the NFPA 37 technical committee raise it to at least 25 feet (pp. 2–3). This is a recommendation by CPSC staff to a standards committee, not a rule: the report says it has not been reviewed or approved by the Commission and may not reflect its views.

Ground, water and snow

Generac asks for a location on high ground where water levels will not rise and flood the generator, and says the unit should not operate in, or be subjected to, standing water. Install it where downspouts, roof run-off, landscape irrigation, sprinklers and sump pump discharge will not flood the unit or spray the enclosure, and where leaves, grass and snow will not block the air inlet and outlet openings. If prevailing winds will cause blowing or drifting, Generac suggests considering a windbreak “at a safe distance” (Generac 10–28 kW installation manual, p. 20). Briggs & Stratton and Champion list the same water sources (Champion adds natural ponding) and the same leaves, grass and snow, and both allow for a windbreak; Champion’s version reads “building a windbreak, planting trees or shrubs within the guidelines and codes applicable” (Briggs & Stratton 17–26 kW manual, p. 10; Champion aXis installation manual, p. 21). Kohler’s RCA site list includes “Not be subject to flooding” (Kohler TP-7091, p. 17). Champion also names roof edges: “Watch out for roof overhangs. Snow, ice or rain shouldn’t be permitted to accumulate on the roof and then cascade onto the unit” (Champion aXis installation manual, p. 21).

For winter, Generac’s Help Center article on snowstorm preparation says there should be no snow piles or large accumulations of snow within three feet of the generator. Where local codes or high precipitation make it necessary, the generator may be installed on a structure that elevates it, on a level base that meets the spatial recommendations in the owner’s manual. Its article on clearing debris and snow from air-cooled units allows snow fences outside the required clearance zones: “The snow fence must be installed at least 3 feet away from the generator”, in a material that is 40–60% porous.

On the base: Generac’s air-cooled units come with an integrated composite pad and are typically approved for pea gravel, crushed stone or a concrete base pad. A gravel or stone bed is about 5 in. (127 mm) thick and about 3 in. (76.2 mm) larger than the footprint on all sides, and the composite pad stays on when the unit is mounted to concrete (Generac 10–28 kW installation manual, pp. 20, 22). The generator must be level within 0.5 in. (13 mm) (p. 21). Kohler asks for a flat, level area covered with a weed barrier and gravel, or a concrete pad, and says not to set its composite mounting pad directly on grass, wood or other combustible materials (Kohler TP-6803, p. 12). Champion says a concrete pad is not required unless federal, state or local code mandates it (Champion aXis installation manual, p. 22).

Sheds, fences and shrubs around a standby generator

Generac answers the shed question in its Help Center article on secondary enclosures: “Generac’s home standby generators are not designed or intended to be enclosed in a secondary enclosure”. The article gives two reasons. An enclosure “may prevent access to safety features (for example, the auxiliary shutoff switch)” that are readily accessible on the outside of the generator in accordance with NEC requirements, and it “may render such generator installation non-code compliant under the NEC and/or local building codes”. On the warranty: “Any damage to a generator caused by enclosing it in a secondary enclosure will not be covered by Generac.” The Help Center article on installing your own generator adds: “Generac does not recommend covers or enclosures.” The snowstorm article explains that the all-weather housing has venting “designed and tested to provide proper airflow and exhaust for the engine in open air”. The installation manual: “Do not alter construction of, installation, or block ventilation for generator” (Generac 10–28 kW installation manual, p. 7).

What Generac’s installation documents do describe is a screen: “A removable barrier (non-permanent; without footings) installed as a visual surround. Removable fence panels cannot be placed within 3 ft (0.91 m) of the generator” (Generac 10–28 kW installation manual, p. 19; Generac Guardian 10–26 kW installation guidelines, p. 16; Generac Protector installation guidelines, p. 11). The PowerPact guidelines and the 2022 Guardian revision measure it at the front: removable fence panels for servicing “cannot be placed less than 3 ft (0.91 m) in front of the generator” (Generac PowerPact installation guidelines, p. 13; Generac 10–24 kW installation guidelines, Rev. B, p. 15). None of these three documents describes a permanent fence or wall. The Protector guidelines (printed p. 8) say among the general location guidelines: “Verify installation site permits sufficient air flow for cooling and ventilation. Consider proximity of any walls, fences, or other noise abatement or security barriers.” The XG manual has the same sentence on p. 14. Neither gives a distance.

On plants, Generac’s tables put shrubs, bushes and trees inside the 3 ft zone at the front and ends and the 18 in. zone at the rear, and say: “Do not attempt to conceal generator with shrubs, bushes, or plants” (Generac 10–28 kW installation manual, pp. 18–19). Vegetation inside these distances “could obstruct air flow”, and exhaust fumes “could inhibit plant growth” (p. 20). The Next Generation owner’s manual asks you to verify that shrubs or tall grasses within 3 ft (0.91 m) of the intake and discharge louvers have been removed (Generac 10–28 kW owner’s manual, p. 18).

On decks and overhangs, Generac’s Help Center article on mounting under a deck says home standby generators “should not be installed under decks, overhangs, or overhead structures of any kind”, and the article on clearance requirements: “Do not install a home standby generator under a wooden deck or platform.” Setting the generator on a roof, platform or deck is a separate case. The manual says it must then be placed in accordance with NFPA 37, Section 4.1.3, with a noncombustible surface beneath the generator and 12 in. (30.5 cm) beyond it, and sends you to the local building inspection or fire department to find out which noncombustible materials are approved (Generac 10–28 kW installation manual, p. 21).

Briggs & Stratton’s manual counts as removable fences “visual surrounds, fence panels, and temporary barriers without footings” and keeps them at least 3 ft (.91 m) from the front of the generator. It says twice not to hide the unit with plants: “never use vegetation to conceal the unit” and “Never use shrubs, bushes, trees, or plants to conceal the generator” (Briggs & Stratton 17–26 kW manual, p. 9). It says never to operate the product inside sheds, under a deck or in other partially enclosed areas (pp. 5, 7). Its location article says the generator should not be placed under a deck or other structure that is closed in and would limit air flow. The manual does not say in explicit words whether a built enclosure around the unit is allowed.

Champion’s aXis manual: “DO NOT place HSB waterproof enclosure under a deck or other type of structure that may confine or restrict airflow”, and avoid installations under decks, inside garages or carports, or in basements (Champion aXis installation manual, p. 21). The manual has nothing on sheds, awnings or screens. Its only fence is in the gas piping rule: the flexible fuel line “must not be concealed within nor contact nor run through any wall, floor, partition or fence” (p. 26).

Kohler’s manuals say the generator set must be installed outdoors (TP-6803: “DO NOT install these generator sets inside a building”; TP-7091: “Do not install or operate this generator set indoors”), and TP-6803 adds that the set “is designed to operate with all enclosure panels and internal baffling in place” (Kohler TP-6803, pp. 11, 13; Kohler TP-7091, p. 11). Both say not to locate the set near patios, decks, play areas or animal shelters (Kohler TP-6803, p. 12; Kohler TP-7091, p. 17). Neither manual’s text mentions fences, sheds, canopies or awnings. The one overhead rule is on the 26RCA drawing, where overhangs and awnings must be at least 5 ft from the generator set (Kohler TP-7091, p. 70).

None of the documents we read gives dimensions for a shed, box or other built enclosure around a standby generator. That covers Generac’s installation documents for the Next Generation, Guardian, PowerPact, Protector and XG lines and its Help Center articles, Kohler TP-6803 and TP-7091, the Briggs & Stratton 17–26 kW manual and its location article, and Champion’s aXis installation manual and Help Center article.

The CPSC staff report adds a reason to keep the area open. It names fences, walls, shrubbery and air conditioning condensing units as obstructions that might affect the flow of exhaust between the generator enclosure and the house, and it counts sheds among the structures that can be entered or occupied (CPSC staff report, p. 28).

Portable generators

For a portable generator, the distance from the house comes from federal agencies, and each words it a little differently.

Agency and document	Distance	Measured from
CPSC, safety alert Portable Generator Hazards (publication 5123)	At least 20 feet	Doors, windows and vents that could allow CO to come indoors
CPSC, winter weather news release 26-326, March 16, 2026	At least 20 feet	The house; not on a porch or in a carport
CPSC, hurricane season news release, May 27, 2026	At least 20 feet	Homes and buildings, with exhaust directed away from windows, doors and vents
CDC, flyer When the power goes out, keep your generator outside	More than 20 feet	Your home, doors and windows
CDC, page Use a Generator Safely (reviewed August 26, 2026)	At least 20 feet	Any doors, windows or vents

CPSC’s safety alert also says: “NEVER use a generator inside homes, garages, crawlspaces, sheds, or similar areas, even when using fans or opening doors and windows for ventilation.” Its winter release explains the porch and carport: “It’s too close to the home and puts your family at risk of CO poisoning.” The same release says to close windows and seal off vent openings that are near the generator or in the path of its exhaust.

The portable generator manuals we read give no 20-foot figure. Only one of them puts a number on the distance to windows and doors:

• Generac iQ3500 (Rev. A, 2018): “Minimum generator placement distance of five feet from windows, doors, or openings in walls with engine exhaust directed away from occupied buildings and if possible downwind”, and five feet of clearance on all sides “to allow for proper ventilation of the generator” (Generac iQ3500 owner’s manual, pp. 2–3).
• Generac GP series: only outdoors and “far away from windows, doors, vents, crawl spaces”; never indoors or in a partly enclosed area such as garages; at least five feet of clearance on all sides “to prevent overheating and fire” (Generac GP series owner’s manual, pp. 2–3).
• Champion 100554: outside and “far away from windows, doors, and vents”; at least 3 ft (91.4 cm) of clearance on all sides “to ensure adequate cooling” and at least 5 ft (1.5 m) from combustible materials; never next to walls or buildings, or anywhere that will not allow adequate cooling or proper exit of the exhaust (Champion 100554 operator’s manual, pp. 4–5, 20).
• Honda EU7000iS: outside, “far away from windows, doors, and vents”, with the exhaust directed away from occupied structures; at least 3 feet (1 meter) from building walls “To prevent a possible fire”, and at least 3 feet of empty space above and around “For proper cooling” (Honda EU7000iS owner’s manual, pp. 8, 52).

The 3 ft and 5 ft clearances in the GP, Champion and Honda manuals are stated for cooling, overheating and fire. CPSC states its 20 feet for carbon monoxide.

Tents and canopies

The manufacturers disagree here, so the answer depends on the brand.

Honda: “Do not enclose or cover the generator with boards or a tent, even when it is outside and away from a building.” The same manual says “Do not enclose the generator in any structure” and “Do not use in the rain or snow” (Honda EU7000iS owner’s manual, pp. 9, 28).

Champion’s 100554 manual says not to operate or store the generator in wet weather such as rain or snow, and in the same section: “If you must operate in rain or damp locations, DO NOT operate without proper protection of the electrical components. Use of a safety canopy that is fire retardant and will provide proper air ventilation for the engine exhaust gas stream may be used.” It points to Champion’s Storm Shield cover (Champion 100554 operator’s manual, p. 20).

Generac’s iQ3500 and GP series manuals do not mention a tent or canopy. Generac’s Help Center article on CO-Sense technology: “All combustion-engine generators are for outdoor use only. There are no exceptions.”

CPSC’s safety alert gives the conditions for wet weather in full: “If you must use a generator when it is wet outside, protect the generator from moisture to help avoid the shock/electrocution hazard, but do so without operating the generator indoors or near openings to any building that can be occupied in order to help avoid the CO hazard. Operate the generator under an open, canopy-like structure on a dry surface where water cannot reach it or puddle or drain under it.” The 2026 winter release sends you back to the manual: “Follow the portable generator manufacturer’s instructions about electrical shock hazards in inclement weather, which may include using an NFPA-rated noncombustible generator tent or may advise you to wait until rain or snow passes.”

When to call a licensed professional

The manuals hand the gas and electrical connections to professionals, each in its own words.

For the gas line, Generac’s installation manual says “Connection of fuel source must be done by a qualified professional technician or contractor” (Generac 10–28 kW installation manual, p. 8), and its Help Center article on installing your own generator: “A certified contractor familiar with local codes should make fuel line connections.” Kohler: “Have the fuel supplier install rigid gas piping and a manual fuel shut-off valve” (Kohler TP-6803, p. 15; Kohler TP-7091, p. 23). Champion, in both its natural gas and LPG sections: “Gas line connections should be made by a certified plumber familiar with local codes” (Champion aXis installation manual, pp. 26, 27).

For the electrical side, Generac: “Only a trained and licensed electrician should perform wiring and connections to unit”, and “Never connect this unit to the electrical system of any building unless a licensed electrician has installed an approved transfer switch” (Generac 10–28 kW installation manual, pp. 6–7). Kohler: “Have an authorized distributor/dealer or a licensed electrician make the following electrical connections” (Kohler TP-6803, p. 25). Briggs & Stratton: “Installation must be performed by a licensed professional”, and “The equipment warranty is VOID unless the system is installed by licensed electrical professionals” (Briggs & Stratton 17–26 kW manual, p. 5). Champion asks for “a qualified electrician or installation technician” familiar with the applicable codes (Champion aXis installation manual, p. 7). For a portable generator, Champion’s 100554 manual says connection to your home’s electrical system “requires a listed 30A transfer switch installed by a licensed electrician and approved by the local authority having jurisdiction” (Champion 100554 operator’s manual, p. 4).

Kohler “strongly recommends that only factory authorized dealers install and service the generator” (Kohler TP-7091, p. 11). Generac’s Help Center says installing as an uncertified installer is possible, but that it is “strongly advisable to work with a certified professional”. The CPSC staff report: “Stationary generators typically are installed by licensed tradesmen” (CPSC staff report, p. 2).

Call a licensed professional in these cases:

• To choose the site and check it against your model’s installation manual and local code. Generac’s Help Center says codes vary by region and to contact your local building inspection department.
• For any gas line or fuel connection.
• For the electrical connection and the transfer switch, standby or portable.
• To move an installed standby generator. Generac’s Help Center says the unit “must be permanently installed and cannot be moved”. Briggs & Stratton says correct tools, equipment and qualified personnel must be used in all phases of handling and moving the generator, and Champion that they should be; Champion’s units weigh approximately 300–500 lb (136–227 kg) (Briggs & Stratton 17–26 kW manual, p. 10; Champion aXis installation manual, p. 23).
• Before you build a deck, fence, screen or snow fence near the unit, so the clearances for your model are checked first.

Before any digging, Kohler says to obtain a building permit and have your local utility companies mark the locations of underground pipes and cables (Kohler TP-6803, p. 11). Generac asks that local utility providers be contacted to verify the site meets all required utility placement requirements before installation, and notes: “This could affect warranty coverage” (Generac 10–28 kW installation manual, p. 20). Champion ties its warranty to the siting rules as well: improper installation “may also result in the warranty being suspended or voided. All the instructions must be followed including location clearances and pipe size” (Champion aXis installation manual, p. 24).

What this page does not cover

• State and local codes, permits and HOA rules. The standby generator manuals here defer to local code, and we did not read any.
• NFPA 37, NFPA 54, NFPA 70 and the ICC codes. They appear here only as the manuals and the CPSC staff report describe them.
• Later revisions of the Kohler manuals. We read TP-6803 (2/21) and TP-7091 (4/23) and did not check for newer ones.
• Other brands and series. Use the installation manual for your own model.

Related pages

To size a generator for the loads you want to run, use the generator size calculator. Generac standby alarm codes, with the manual page for each, are on the Generac error codes page. Snow at the louvers, exercise settings and cold-weather checks for a standby unit are on the winter home maintenance checklist.

See also

• Generator size calculator
• What a standby generator does when the power goes out: transfer, retransfer and the weekly exercise
• Home maintenance schedule from the manuals: monthly to yearly
• Winter home maintenance checklist: furnace, boiler, water heater

Error codes: Generac