How our cost estimates are built
Every number on this site is a planning estimate, not a quote. This page explains where the ranges come from, what they include, how the tools adjust them, and where they stop being useful. Last full review: November 2026.
What a range is
Each project has two bands: a DIY range (parts and materials you would buy at a home center for a mid-grade product, with nothing for your time) and a professional range (labor plus materials for a standard, accessible installation, including haul-away and a typical permit where one is normally required). The bands are typical 2026 U.S. figures compiled from published national contractor cost guides and current retailer pricing, then rounded into sensible steps so they read as what they are — a budget envelope, not a price.
The 25-project cost planner uses those bands directly. The project calculators go one level deeper: each has its own inputs (square footage, tonnage, AFUE, pump type and so on) and a published formula, and each page shows the line items behind the number so you can see what moved it.
What the figures do not include
- Work that is discovered after opening things up: rotted sheathing, seized shutoff valves, a cracked flange, aluminum wiring. The calculators call these out and price the common ones as separate lines, but they cannot see your house.
- Emergency or same-day premiums, which commonly add 20–40%.
- Premium materials or brands beyond the mid-grade assumption, unless the calculator offers that choice.
- Sales tax, financing costs, and any rebate or tax credit. Where a federal credit has ended (the Section 25C credit ended for property placed in service after December 31, 2025) the pages say so rather than assume a saving.
Regional adjustment
We do not license a city-level cost index and will not pretend to. The planner offers a broad area multiplier that you choose; it is applied to the professional range (labor varies far more by region than parts do) and only lightly to DIY materials:
| Area cost level | Typical of | Pro multiplier | DIY multiplier |
|---|---|---|---|
| Lower-cost area | Rural areas and many small cities in the South and Midwest | ×0.85 | ×0.95 |
| Typical (national) | Most suburbs and mid-size metros | ×1.00 | ×1.00 |
| Higher-cost metro | Large metros: Chicago, Denver, Atlanta, Phoenix, Minneapolis, Portland | ×1.15 | ×1.05 |
| Highest-cost metro | NYC, SF Bay Area, LA, Seattle, Boston, DC, Hawaii, Alaska | ×1.35 | ×1.10 |
The fastest real calibration is one or two local quotes; plug the quoted material figure back into the planner and the rest of the budget follows.
Contingency
The planner adds 10% by default and lets you set 0–50%. Older homes, anything behind a wall or under a floor, and any job involving the roof deserve the higher end. The single-project calculators do not add contingency; their line items make the risk visible instead.
DIY suitability and safety boundaries
Each project carries a suitability label — reasonable first project, experienced DIY only, or licensed professional recommended — and the pro-only projects (electrical panels, EV circuits, central HVAC replacement, gas furnaces, full roof replacement) are priced at professional rates only. The boundaries follow published guidance rather than our opinion: EPA Section 608 certification for refrigerant handling, OSHA’s 6-foot fall-protection rule as the reason roof work is a crew job, the EPA lead-safe rule for pre-1978 paint, CPSC guidance on water-heater temperature and GFCI testing, and the manufacturer installation sheet for anything we describe step by step.
Who writes and reviews this
The site is written and maintained by its owner, Ken Hoven, who is not a licensed contractor and does not claim to have performed every repair described. Figures are reviewed on a set cadence (the current review date appears on each guide and calculator), and corrections are made when a reader, a source, or a real quote shows a band is off. If you have a recent quote that is well outside a range on this site, tell us — that is the most useful feedback we get.
Affiliate and referral relationships
Tool picks on the toolkit page use Amazon affiliate links and say so next to the link. Contractor-referral links are not active on this site; when they are, each one will carry a disclosure next to it. Neither relationship changes a cost range. The full disclosure has the details.
Primary references used across the calculators
- OSHA — Fall protection in residential construction (6-foot rule, 29 CFR 1926.501(b)(13))
- U.S. CPSC — Tap Water Scalds safety alert (120°F thermostat setting)
- IRS — Energy Efficient Home Improvement Credit (25C): allowed for property placed in service before Dec 31, 2025
- U.S. EPA — Section 608 technician certification requirements (refrigerant handling)
- U.S. DOE — 2023 central air conditioner efficiency standards FAQ (SEER2)
- AHRI — Understanding the 2023 energy efficiency standards (SEER2 / HSPF2)
- U.S. EPA — Lead Renovation, Repair and Painting (RRP) program: pre-1978 homes
Cost figures themselves are compiled from published national contractor cost guides and retailer pricing current as of November 2026; individual retailer and guide pages change too often to cite as fixed links.