Where do the calculator's prices and measurements come from?
Prices come from recorded HomeGuide component references, with their original source and retrieval date. Measurements come from the walls you select or measurements you enter; a footprint is not an inspection. Available property observations identify their provider and limitations.
The main home calculator uses national rates. Separate city examples can use a disclosed BLS labor wage proxy for supported sump labor only. These sources help with planning and do not establish a local contractor quote.
Key facts as of Oct 30, 2026. Sources and recorded dates.
What measurements and sources are used?
Choose the space, address, affected walls, depth and finish, symptoms, entry point and method. Confirm a building match explicitly, or enter your own measured wall length.
Property lookup availability and outline quality vary; selected walls can be edited. A floor footprint does not establish buried wall depth, structural condition or the cause of a leak.
- US Census Geocoder: address-location reference.
- OpenStreetMap contributors: attribution for available building/map data.
- USGS 3D Elevation Program: elevation context when available, not an on-site drainage survey.
Use the source and status shown with an observation. Unavailable property context is not evidence that a home is safe, dry or outside a flood risk.
How are the price range and midpoint calculated?
Recorded component rates were retrieved on Oct 24, 2026. Each line uses the unit named in its source record. The main home calculator uses national references; the city planning examples and separate component tool can adjust only published sump labor using a compatible metro-to-national wage ratio.
| Work | Planning range |
|---|---|
| Interior drain tile / sump system | $40–$85 / ft |
| Sump pump installation | $600–$2,500 / installation |
| Minor crack injection | $250–$800+ / minor crack |
| Exterior membrane only | $4–$7 / ft² of wall |
| Crawl space encapsulation | $3–$10 / ft² of floor |
The 100 ft interior-drain example uses the same recorded rate and calculation engine. A midpoint is the average of the low and high endpoints, not a measured market average. Open-ended references have no supported midpoint.
An interior-drain package may already include a sump, so a separate pump is not added.
BLS Occupational Employment and Wage Statistics: May 2025 wage vintage, retrieved Oct 24, 2026. Employee wages are a labor proxy, not installed contractor prices; materials and unsupported combined costs do not scale.
What still needs an inspection?
Taxes, finish restoration, excavation access, permits and unmeasured work need separate confirmation. A suggested method follows your answers and cannot diagnose structural damage, groundwater conditions or a safe discharge route.
PNNL's pre-retrofit assessment explains why water sources and existing building conditions need investigation before enclosure or insulation work. A contractor confirms the scope and final price on site.
See the price guide and start the calculator with measurements you can explain. Source records describe national planning references, not verified contractor availability.
Sources and dates
Public guidance checked Oct 30, 2026. Cost references retain the recorded Oct 24, 2026 retrieval date; this guide adds no new price observations.
- University of Minnesota Extension: Moisture in basements, causes and solutions
- PNNL Building America: Pre-retrofit assessment of crawlspaces and basements
- PNNL Building America: Foundation wall water/damp-proofing
- PNNL Building America: Water management of existing crawlspace floor
- PNNL Building America: Sump pump cover gasket
- HomeGuide: basement waterproofing cost — recorded Oct 24, 2026.
- HomeGuide: french drain cost — recorded Oct 24, 2026.
- HomeGuide: crawl space encapsulation cost — recorded Oct 24, 2026.
- HomeGuide: sump pump installation cost — recorded Oct 24, 2026.
Read how the calculator works and the source inventory for calculation limits.