By Kjel Jones — independent custom-home researcher for Ashton and the Henry’s Fork corridor. Not a builder and not a general contractor. Licensed Idaho real estate agent, LPT Realty.

Published 2026-09-03

60 decibels by day, 50 by night, measured at your neighbour's line.

There is a number, and it is measured at the neighbour's line

Noise complaints on corridor acreage usually get argued in adjectives. The county has a table instead, and the useful thing about a table is that it settles the argument in advance for anyone who reads it before starting work.

“No application that creates excessive levels of sound beyond its property line shall be permitted. Excessive sound, measured at the property line of the receiving use, exceeds the standards of Table H.1.”

— Fremont County Development Code, 2011 Edition (Ordinance 2011-04), Appendix H, section 1.01, Maximum Sound Levels. Consolidated through Ordinance 2026-03. Retrieved 1 September 2026

Note where the measurement is taken. Not at the source, not at the boundary of the property making the noise, but at the property line of the receiving use — the line of whoever is being disturbed. On large parcels that distinction is worth a great deal, because distance is doing work for you before the meter ever comes out.

Table H.1, in full

The code adds its own footnote that dBA is the measure of sound levels in A-weighted decibels.

Two features are worth drawing out. The residential standard drops by ten decibels at night, and because decibels are logarithmic that is a substantial tightening rather than a modest one. And the standard attaches to the receiving use, so what you are allowed to emit depends on what is next door rather than on what you are. The same generator is measured against 60 dBA beside a house and 70 dBA beside a shop.

What the standard does not reach

The applicability section is unusually generous, and knowing what falls outside is as useful as knowing the numbers.

The standard applies to sounds generated by the use or operation of an application, including the operation of trains, motor vehicles, and heavy equipment on the site. It does not apply to:

• The movement of trains on existing railroad rights-of-way.
• The movement of motor vehicles on public roads.
• The operation of farm machinery.
• The operation of watercraft.
• Other sources of noise not attributable to a particular application.

The farm machinery exclusion is the one that matters most around Ashton, Drummond and Warm River. Agricultural operations are outside this standard entirely, which means a buyer moving onto ground beside working farmland has no recourse under Appendix H for the sound of that work. That is a reasonable thing to know before choosing a building site rather than after.

The distinction between the two vehicle provisions is subtle and worth reading twice. Heavy equipment operating on the site is inside the standard. Motor vehicles moving on public roads are outside it. The same truck can be inside the rule in the yard and outside it on the highway.

Put plainly, the questions that decide whether a given source is a problem are these:

• What is the receiving use on the other side of the nearest boundary, residential or commercial?
• How far is that boundary from the source, since the measurement is taken there rather than here?
• Does the source run at night, which moves it onto the 50 dBA figure rather than the 60 dBA one?
• Is the source temporary construction, permanent operation, or excluded farm machinery?
• Is it operating on the site, or moving on a public road, since only the first is inside the standard?

Construction gets an exception, with a time limit

Building anything makes noise, and the appendix says so directly. The maximum sound levels of Table H.1 may be exceeded by temporary construction and maintenance activities — but any excessive noise generated by those activities is restricted to the hours between 7:00 A.M. and 10:00 P.M.

That is a fifteen-hour window, which is generous, and it is the practical governing rule for anyone building a house here. Read carefully, it says three things:

• The exception is for temporary construction and maintenance, not for a permanent operating condition.
• Inside the window, the decibel limits may be exceeded.
• Outside the window, they may not — so early starts before 7:00 A.M. are the exposure, and on a short building season an early start is exactly what a crew wants.

Ten in the evening is later than most crews work. Seven in the morning is later than some of them start. That asymmetry is where a construction noise complaint usually comes from, and it is avoidable simply by knowing the number.

How this interacts with the rest of a build

A few practical consequences follow from a standard written this way, and they are worth holding together.

1. Find out what the receiving uses around you are, since residential neighbours put you on the tighter figure while commercial ones do not.
2. Establish how far the nearest receiving property line is, because the measurement is taken there and distance is the cheapest mitigation available.
3. Site permanently noisy equipment — generators, heat pumps, shop equipment — with the night-time 50 dBA figure in mind rather than the daytime one, because equipment that runs at night is measured against the lower number.
4. Keep construction noise inside 7:00 A.M. to 10:00 P.M., and treat the morning end as the real constraint.
5. If neighbouring ground is farmed, understand that the farm's own machinery is outside this standard, and factor that into siting a bedroom rather than into a future complaint.
6. Where a buffer is required for other reasons, remember it is doing acoustic work too — a planted, bermed separation is measured at the far side of it, which is one more argument for taking the buffer calculation seriously.
7. If a genuinely noisy permanent use is proposed, deal with it at application stage. The standard is framed as a condition of what may be permitted, not only as an enforcement rule afterwards.

For an ordinary house on corridor acreage none of this will ever be tested. It becomes live where a shop, a generator, a heat pump or a home business runs close to a boundary, and where the neighbour's use is residential — which on this corridor is the common case, and one more of the things that varies lot to lot rather than applying uniformly.

Common questions

How loud am I allowed to be in Fremont County?

Measured at the property line of the receiving use: 60 dBA between 7:00 A.M. and 10:00 P.M. and 50 dBA between 10:00 P.M. and 7:00 A.M. where the receiving use is residential, and 70 dBA at any time where it is commercial or industrial.

Where is the noise measured?

At the property line of the receiving use — the boundary of whoever is being disturbed, not at the source or at the emitting property's own line. On large parcels distance therefore does a great deal of the work.

Does the limit change at night?

Yes. For a residential receiving use it drops from 60 dBA to 50 dBA between 10:00 P.M. and 7:00 A.M. Because decibels are logarithmic, ten decibels is a substantial tightening rather than a small one.

Can I run construction equipment outside those limits?

The maximum sound levels may be exceeded by temporary construction and maintenance activities, but any excessive noise from those activities is restricted to the hours between 7:00 A.M. and 10:00 P.M.

What time can a crew start work?

The construction exception runs from 7:00 A.M. Before that hour the ordinary limits apply, so an early start is where construction noise complaints usually originate on a short building season.

Does the noise standard cover farm machinery?

No. The standard expressly does not apply to the operation of farm machinery. A neighbour on working agricultural ground has no recourse under this appendix for the sound of that work.

What else is excluded?

The movement of trains on existing railroad rights-of-way, the movement of motor vehicles on public roads, the operation of watercraft, and other sources of noise not attributable to a particular application.

Is heavy equipment covered?

Yes, when operated on the site. The standard applies to sound generated by the use or operation of an application including trains, motor vehicles and heavy equipment on the site. The same vehicle moving on a public road is outside it.

Does the limit depend on what I am, or what my neighbour is?

On your neighbour. The standard attaches to the receiving use, so identical equipment is measured against 60 dBA beside a residence and 70 dBA beside a commercial or industrial use.