Dataset · v1.0.0 · 18 rows
Cost driver index
What actually moves a radon mitigation quote, in which direction, and by how much relative to a baseline job — a structured cost model for comparing two bids on the same house.
Cost drivers by category
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The data
| Cost driver | Category | Direction | Relative magnitude | Observable before quoting | Why it moves the price |
|---|---|---|---|---|---|
| Number of distinct soil-contact zones | foundation | increases | major | true | Each zone — basement slab, crawl space, slab-on-grade addition — may need its own suction or membrane, and a bid covering only one zone has priced a different house. |
| Crawl space requiring sealed membrane | foundation | increases | major | true | Membrane material scales with area and the labour happens in a confined space, which is slow regardless of hourly rate. |
| Crawl space headroom and access | access | varies | moderate | true | Eighteen inches of clearance with a small hatch and ductwork in the way multiplies the hours the same square footage takes. |
| Finished basement over the slab | access | increases | moderate | true | Suction placement is constrained to where the slab can be reached, routing must use chases, and any opened surface has to be made good. |
| Suction points indicated by diagnostic | design | increases | major | false | Each additional point is another core, more pipe, and more sealing. How many are needed is measured, not assumed. |
| Sub-slab material permeability | design | varies | moderate | false | Clean aggregate lets a single point serve a large slab; tight or inconsistent fill limits how far the pressure field extends. |
| Interior chase available for the riser | access | decreases | moderate | true | An internal route through a closet or mechanical chase to an attic fan is usually tidier and cheaper than an exterior run with weatherproofing. |
| Exterior routing on a visible elevation | access | increases | minor | true | Longer pipe, exterior fastening and sealing, and often paint to match trim. |
| Fan matched to measured static pressure | equipment | varies | minor | false | Right-sizing changes the unit price modestly and the operating cost and noise substantially. Oversizing is not an upgrade. |
| Open sump pit requiring sealed lid | design | increases | minor | true | A sealed, gasketed lid is inexpensive and often converts the pit into an efficient suction point, so it can reduce the total. |
| Untrapped or dried floor drains | design | increases | minor | true | Each is a direct path to the sub-slab layer that bleeds suction; the remedies are cheap but must be in scope. |
| Hollow block foundation walls | foundation | increases | moderate | true | Block cavities act as vertical channels connected to soil, so sealing the open top course becomes a line item. |
| Dedicated electrical circuit and disconnect | compliance | increases | minor | false | Fans run continuously and need proper circuit provision; distance to the panel drives the cost. |
| Local permit required | compliance | increases | minor | false | A local building-department question rather than a state one. The scope should name who pulls and pays for it. |
| Post-mitigation verification test included | verification | increases | minor | false | A small line that is the deliverable of the whole job. Its absence is the most common reason a bargain bid is cheaper. |
| Remedy clause for a failed verification | verification | increases | moderate | false | A scope committing to an outcome prices the risk of returning. A scope committing only to an installation does not, and moves that risk to you. |
| Exposed soil section behind finished wall | foundation | increases | moderate | false | Discovered on a site visit rather than from photographs, and usually requires membrane work the original bid did not contemplate. |
| Radiant tubing embedded in the slab | design | increases | moderate | true | Loops must be located before coring, which adds survey time and constrains where suction can go. |
Download and API
- cost-driver-index.csv — 18 rows, comma separated.
- cost-driver-index.json — rows plus the field schema, methodology, and version. Stable URL, same origin, no key required.
- index.json — the catalogue of every dataset, for programmatic discovery.
Licence. CC BY 4.0 — reuse with attribution to Radon Connect and a link to the dataset page.
Field schema
| Field | Type | Description |
|---|---|---|
driver | string | The variable that moves the price. |
category | enum foundation · access · design · equipment · compliance · verification | Which part of the job the driver belongs to. |
direction | enum increases · decreases · varies | Effect on the quote relative to a baseline job. |
magnitude | enum minor · moderate · major | Size of the effect relative to a baseline poured-basement retrofit. A relative class, deliberately not a dollar figure. |
observable | boolean | Whether a homeowner can assess this themselves before contractors arrive. |
why | string | The mechanism. |
Methodology
The question this answers
When two radon mitigation quotes on the same house differ, which variable explains the gap — and in which direction?
How a row comes to exist
- Drivers were derived from the design decisions a mitigation scope must specify: suction placement and count, routing, sealing scope, fan selection, electrical, and verification.
- Direction and magnitude are stated relative to a baseline job — a single-zone poured basement with accessible slab, interior routing, and one suction point.
- Magnitude is a three-level relative class, deliberately not a dollar amount or a percentage. We hold no quote data and will not imply that we do.
Inclusion and exclusion
- A driver qualifies when it changes the scope of work rather than only the contractor’s margin.
- Market factors — local labour rates, competition, seasonality — are excluded because they vary by area and we have no basis to quantify them.
What this dataset cannot tell you
- This dataset contains no prices and cannot be used to estimate one. Its purpose is to explain a difference between two real quotes on a real house.
- Magnitude classes are editorial judgements informed by scope content, not measurements. Two contractors could reasonably rank adjacent drivers differently.
- A driver marked observable can be assessed by a homeowner; it does not follow that a homeowner should skip the site visit.
Related
- Mitigation System Component and Service-Life Dataset — What each part does, how it fails, and whether you would notice.
- Radon Quote Line-Item Comparison Dataset — Instrument published, N = 0. What we will collect, and why we will not estimate first.
- Cost drivers — Seven variables that explain nearly every price difference.
- Comparing radon contractors — Compare scopes, not totals. Most bid gaps are scope gaps.
- Average cost explained — What the published ranges mean and where your house falls in them.
- Research Center — every dataset, with its provenance and status.
- Research methodology — how this platform builds and checks content.
Sources
- U.S. EPA — Radon
- U.S. EPA — Consumer’s Guide to Radon Reduction
- U.S. EPA — A Citizen’s Guide to Radon
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