Guides

Guides to building a custom home in Ashton

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 2026-08-13 · every figure below was checked against its primary source on the date shown.

What is published so far

• Idaho's contractor registration rule: sworn application, $300,000 insurance, and a number on the face of your permitSince January 1, 2006 it has been unlawful to hold yourself out as a contractor in Idaho without registration: application under oath, workers' comp proof, a $300,000 single-limit liability policy including completed operations, and the registration number conspicuously entered on every building permit. The exemptions, the twelve-month owner-builder trap, and the lien rights an unregistered builder conclusively waives.Published 2026-09-28
• The three transient rental tiers in Fremont County: 15 occupants, 30 occupants, and the commercial cliffFremont County's Appendix I transient rental rules in plain terms: 30 consecutive days defines the use; 15 or fewer overnight occupants takes a Class I permit, 16 to 30 a Class II conditional use, more than 30 is commercial zoning territory. Plus the 150 square feet per occupant cap, the local agent whose number must be posted for neighbours, the roadway-access rule amended in 2016, and the clause that fails any rental that misses a single requirement.Published 2026-09-26
• Keeping animals on a residential lot in Fremont County: two horses or ten sheep per acre, and the 300-foot rule that decides if your land countsFremont County code section 5.23 in plain terms: residential means platted or within 300 feet of a neighbour's house; livestock caps at two horses, pigs or cows per acre, ten llamas, sheep or goats counting offspring until weaned; one-acre minimum for livestock; fowl scale proportionally below it; seven days of pack animals in hunting season; and the 250-animal cliff into confined-feeding rules.Published 2026-09-25
• Why you can't look up Ashton's flood zone online - and what your lender does insteadFEMA's flood map layer holds zero digitized panels for all of Fremont County, while the county has been in the National Flood Insurance Program since 1985 - so an Ashton address search returns nothing, and lenders fall back on paper-era records. What the blank screen means, what it never means, and the Letter of Map Amendment route when a determination is wrong.Published 2026-09-24
• The City of Ashton excavation permit: $100 fees, Dig Line notice, and the ten-day repair clockAshton's excavation permit governs any dig in the public right-of-way: a $100 hard-surface fee, Dig Line notice two business days ahead, Class A backfill, a ten-day repair clock, and a 180-day fee holdback. Read condition by condition.Published 2026-09-23
• Ashton's snow load: the city's form prints 70 lbs, the county ordinance says 90 PSFTwo official documents disagree about Ashton's snow load: the city's permit form prints 70 lbs; the county ordinance assigns 90 PSF; the U of I study says 103. What to ask before a roof is designed.Published 2026-09-22
• The City of Ashton's own building-permit application, walked through field by fieldThe city's one-page building-permit application: eighteen checkboxes, the Contractor # field, the legal lot-block-sub line, a square-footage grid, and the snow-load sentence the form itself prints. Fees are filled in by the office, not printed.Published 2026-09-21
• Ashton publishes its own code: seventeen titles, current through Ord. 503-23 (passed April 12, 2023)Ashton's city code runs seventeen titles — five of them reserved — in a free online library, current through Ord. 503-23, passed 4-12-2023. What the table of contents proves, and what it cannot tell you without the city's viewer.Published 2026-09-16
• What seismic design category is Ashton? D — and the free USGS query that proves itA one-question page with an official answer: the USGS design service returns Seismic Design Category D for Ashton's coordinates, Site Class D, Risk Category II — SDS 0.458 g, SD1 0.264 g, verified 11 September 2026.Published 2026-09-15
• The 48-business-hour inspection clock and the 10 percent refund: Idaho's 2025 building-code change, read at AshtonIdaho Code 39-4118, added by the 2025 legislature: 48 business hours to answer an inspection request, a written reason within three days, and two refund routes. What it changes on a corridor permit file.Published 2026-09-14
• The master plan rule: the county judges a subdivision against every acre the developer owns — and writes itself into your covenantsA subdivision can be denied solely for lacking a master plan of the owner's entire contiguous holdings. County-required covenants can't change without the Board's written consent, and a POA's covenants must carry nine minimums — liens included.Published 2026-09-12
• The Fremont County Agricultural Protection Area file: five contiguous acres, $25.00, all four pages — and the neighbor protections written into itThe county's own APA packet: seven tests the land must pass, seven more the county weighs, the Section 3 evidence checklist with its city and highway-district statements — and the attestation that a designation cannot limit any other property.Published 2026-09-11
• What Fall River asks for before crews can schedule your powerThe co-op's own checklist: a site plan that must show any future buildings, an approved plat in subdivisions, load and voltage, fees paid in advance — and the meter's location is the co-op's decision, not yours. Temporary power has its own permit.Published 2026-09-10
• Underground power, easements drawn on the plat, and capacity in writing — Fremont County's subdivision utility rulesThe code made the developer prove utilities before your lot existed: easements drawn on the final plat, written certification of capacity from every utility, underground power, services in before the road surface. The plat you inherit is the record.Published 2026-09-09
• Fremont County's last adopted permit fee schedule, in full: $55.00 a square foot, $19.00 to $4,487.00, dated 2005Ordinance 2005-02 adopts the county's only published building-fee amounts: $55.00 a square foot to value a house, a ladder from $19.00 to $4,487.00, plan review at 30 percent, a $42.00 hour. Printed as adopted, dated 2005 — nothing since confirms it.Published 2026-09-08
• A road does not stop your neighbour being 'adjacent' — and four other words the county has redefinedOrdinary words carry specific meanings here. Adjacent reaches across a road. Accessory needs a principal use already on the lot. And a significant impact can exist even where the community approves.Published 2026-09-07
• A family burial ground is permitted here — but the deed has to be recorded before the first intermentThe county calls private family burial grounds a public benefit. The whole mechanism is a description recorded on the deed before any interment, plus a duty to disclose it when the land is sold.Published 2026-09-05
• A household wind turbine is a Class I permit in every district — unless you are within two miles of a scenic bywayA small wind system of up to two towers is permitted in all zoning districts, but no wind system is allowed within two miles of a scenic highway corridor, and large systems are prohibited countywide. After that the constraint is geometry: the setback equals the machine's total height from every property line.Published 2026-09-04
• 60 decibels by day, 50 by night — and construction noise stops at 10 p.m. and cannot start before 7 a.m.The county measures noise at your neighbour's property line, not yours. Construction may exceed the limits only between 7 a.m. and 10 p.m., and farm machinery is excluded from the standard entirely.Published 2026-09-03
• A buffer is arithmetic: four trees per hundred feet, a height charge over 25 feet, and 30 percent back for plantingBuffer width is calculated, not chosen. Four major trees per hundred feet is the baseline, height over 25 feet widens it, and berms and planting earn up to 30 percent back — never below ten feet.Published 2026-09-02
• Phasing a subdivision: the guarantee covers a year's maintenance, and a missed schedule voids your vested rightsYou can sell lots before the improvements are built. The guarantee covers completion, repair and one year's maintenance — and missing the schedule without re-negotiating inside 90 days voids the agreement.Published 2026-09-01
• One house on any lot. A second one needs 1.5 acres and a good deal more.One primary dwelling is allowed on a lot of any size, subject to the health district. A second needs 1.5 acres, perpetual common ownership, and zoning that permits it.Published 2026-08-29
• Seventy feet: the county's wildfire requirement, and the plan that goes with the platThe code requires seventy feet of defensible space around a dwelling, no woody growth within five feet of a structure, and limbs pruned below six feet. New construction files a wildfire plan with the plat.Published 2026-08-28
• Building in the Floodplain Overlay: where clearing and grading suddenly need a permitInside the Floodplain Overlay, any activity that may affect flood flows needs a permit - including clearing, grading and fill that are exempt elsewhere. Plus the five-acre threshold for base flood elevation data.Published 2026-08-27
• There is no published snow load for Chester or Marysville — and the ordinance won't tell you eitherThe University of Idaho study has stations at Ashton, Warm River and Drummond, and none at Chester or Marysville. The ordinance assigns by district and defines no boundary in text. Two different gaps, and neither fills the other.Published 2026-08-26
• Fremont County does not publish what a building permit costs — and it has two Section 4sFive documents on the county Building page, none with an amount on it, and a 2026-revised checklist stating no figures at all. The only adopted schedule is from 2005, in the second of two consecutive sections both numbered 4.Published 2026-08-25
• Getting power to a Henry's Fork lot: the co-op charges $250 just to tell you what it costsThe fee is charged whether or not you are ready to build, so pricing two lots is a real line item. Then membership, the easement that is a condition of service, and aid to construction — the number that actually varies by thousands.Published 2026-08-24
• What "custom" actually means here: plan sets, allowances, and the exclusions listThe county settles part of it — an engineered, stamped set with truss designs is a submission requirement on the corridor. The rest is the allowance schedule and the exclusions list, which is where two bids stop being comparable.Published 2026-08-22
• The energy code on an Ashton build: two ways to comply, and the sheet the county usesREScheck trades components against each other; the county's prescriptive path does not. Its Climate Zone 6 values reproduced in full — plus the two things that sheet does not tell you, including any window figure at all.Published 2026-08-21
• Who pulls the building permit, owner or builder — and what changes either wayThe county wants the landowner's signature. A builder can pull it instead, but only on a signed permission letter the county publishes as a form. What each route changes about notice, corrections, and who holds the file if you part ways mid-build.Published 2026-08-20
• What actually differs from lot to lot on the Ashton corridor?Frost depth and the adopted codes are fixed countywide. The snow-load district is not — it can swing 25 PSF between lots a few miles apart, and the map that settles it is a scanned image.Published 2026-08-19
• The Fremont County snow-load district almost nobody names: North Fork Highlands, 115 PSFThe county ordinance defines a district above Ashton that no builder site and no cost calculator mentions. If your lot falls in it, the design load jumps 25 PSF over the Ashton District figure.Published 2026-08-18
• Log, timber frame and SIP homes in Ashton — who actually builds them hereThis is the corridor’s deepest lane and it is genuinely local: two firms have run log and panel work here for decades. What separates the three systems on an Ashton lot, and what each does to your permit file.Published 2026-08-17
• How deep do footings have to go in Fremont County? Thirty-two inches.The county sets one minimum frost depth and it applies to the whole county, not just the cold end. What 32 inches means for your foundation quote, your excavation bid, and pouring late in the year.Published 2026-08-15
• Ashton’s snow load is 90 PSF — the state’s own study says 103. Which number holds up your roof?Fremont County Ordinance 2005-02 sets one figure for the whole Ashton District. The University of Idaho’s 2015 reference gives Ashton 103 psf, Warm River 108, Drummond 114. What your engineer designs to, and the question to ask before plans are drawn.Published 2026-08-13
• Well and septic on an Ashton acreage lot — what to confirm before you buyA corridor lot with no water and no approved drainfield is a lot you cannot build on this year. The diligence order that keeps a purchase from stalling, written at Ashton and Drummond addresses.Published 2026-08-13
• The Fremont County permit path for a new house in Ashton, step by stepWhich county form starts the file, what the building department wants attached, where the snow-load certification enters, and the 2026-revised letter most applicants have never seen. Every document ID verified live.Published 2026-08-13
• What does it cost to build a custom home in Ashton, Idaho?No builder on the corridor publishes a price, and there are honest reasons — snow-load framing, well depth, septic design, and a short season. What is actually published, what drives the spread, and how to make three bids comparable.Published 2026-08-13

The two numbers most of these guides come back to

Almost every question about building here lands on the same county ordinance. It is worth reading once in its own words:

“Section 3. Ground Snow Load: The ground snow load shall be … 115 PSF. for the North Fork Highlands district. 90 PSF. for the Ashton District…”

“Section 4. Minimum Frost Depth for Footings: The minimum frost depth for footings shall be 32 inches.”

— Fremont County Ordinance No. 2005-02, Sections 3 and 4 (county-published PDF, retrieved 13 August 2026)

• 90 PSF ground snow load in the Ashton District, and 115 PSF in the North Fork Highlands district above it — two of the four districts the ordinance defines.
• 32 inches minimum frost depth for footings, applied countywide.
• 2018 IRC, IBC and IECC are the adopted codes, so energy-code compliance is part of the permit file, not an afterthought.
• The snow load varies by district; the frost depth does not. One number depends on where your lot sits and the other applies across the whole county.

How a guide gets written

1. A real question arrives from someone actually building, buying or subdividing here.
2. The primary document is read in full — the county ordinance, the county form, the state study — never a search-result summary of it.
3. Figures are quoted with their source and retrieval date, so the claim can be checked and a stale one is obvious.
4. The page says where the answer runs out and names the office or licensed professional who owns the rest of it.

Related reading on this site

• The builder table — the six firms working out of Ashton and the corridor, with registration numbers
• Who writes this — the researcher behind the site, and what he is not
• How this site is paid — the business model in plain language, including what it costs you
• Reviews and references — why there are no testimonials here yet, and what to ask for instead

Common questions

What do these guides cover?

The things a Fremont County building file actually turns on: the Ashton District snow load, the 32-inch frost depth, the county permit sequence, well and septic diligence on acreage, what drives a custom-home price here, and which builders run log, timber and structural insulated panel work.

How often is a new guide published?

Most weekdays, never on a Sunday. Longer pieces land Monday, Wednesday and Friday; shorter single-question answers fill the days between. Each page carries the date it was published and the date its figures were last checked.

Are the numbers in these guides verified?

Yes, and against the original document rather than a summary of it. The 90 PSF and 32-inch figures come from the text of Fremont County Ordinance No. 2005-02 itself. Where a county form is cited, it was fetched on the date shown to confirm it was still live.

Why do some links to county documents break?

Fremont County renumbers its DocumentCenter files from time to time — the building permit application has already moved once. Every county link on this site is re-checked when a page is updated, and the document table on the home page is the single place they are maintained.

Do the guides cover Island Park or St. Anthony?

No. This site is Ashton, Chester, Drummond, Warm River and the Henry's Fork corridor between them. Other parts of Fremont County sit in different snow-load districts with materially different design figures, and mixing them is how people end up quoting the wrong number to an engineer.

Can I ask for a guide on something specific?

Yes, and those make the best pages. If you are working through a question about a corridor lot and cannot find a straight answer anywhere, send it over — the answer becomes a guide if it is likely to help the next person too.

Is any of this legal or engineering advice?

No. It is research, sourced and dated so you can check it. Design figures belong to a licensed Idaho structural engineer, permit decisions belong to the county building department, and the construction belongs to the builder you hire.

Does a builder pay to be featured in a guide?

No. No builder has paid for placement, wording or omission in anything published here, and the table of local firms is compiled from public records. How the site is funded is set out in full on its own page.