What is a geotechnical report?
Geotechnical reports indicate whether a particular site is suitable for the construction of a permanent or temporary structure. Geotechnical reports assess the safety of the proposed construction by indicating whether the soil and other geological conditions of the site will provide the necessary support for the development. A geotechnical report may be required before the construction of buildings, walls, roads and other structures.
Please note: As part of the geotechnical report, a subsurface investigation is required, which will include borings on the site, and may require heavy equipment on the site.
When is a geotechnical report required?
The applicant must submit a geotechnical report in the three situations described below.
1. Landslide-Prone Overlay (Zoning Code §906.04):
- Any application for new construction or for a multi-story addition, must submit a full geotechnical report
- Any application for a parking pad, deck, porch, stoop, balcony, retaining wall or one story addition, must submit evidence from a certified geotechnical professional that the proposal will not increase the susceptibility of landslides on the subject property or surrounding property
2. Undermined Area Overlay (Zoning Code §906.5):
- Any application that includes new construction or an enlargement of an existing structure in the Undermined Overlay must submit a Coal Status Report with maps from the State Bureau of Mines. The Coal Status Report may be requested for a specific property address or parcel ID by emailing email@example.com or calling 724-769-1100
- For single family dwellings, a geotechnical report is required only if the Coal Status Report shows less than 100 ft of overburden
- For all other new construction or enlargement of existing structures, a geotechnical report is required regardless of the amount of overburden
3. Steep Slopes (Zoning Code §915.02.A.1);
- Cut or filled slopes shall not exceed 25% unless the applicant submits a geotechnical report that certifies the safety and suitability of such slopes
When is a geotechnical report not required?
Typically if you have a smaller project with little or no impact to the soils, a geotechnical report may not be needed. This is not an exhaustive list, but it provides examples of construction in which a geotechnical report may not be required:
- Installation of fences no taller than 6 feet
- Project has no impact to the site (i.e. interior renovations, etc.)
- Deck renovation with no change to the posts or structure
- Sheds less than 120 sq ft
- Exterior repair of an existing structure when there is no alteration to the building envelop
If any of the above items will change the slope or are located near the edge of the slope, the applicant will need to submit evidence from a certified geotechnical professional that the proposal can be safely accomplished.
If you have an existing approved geotechnical report and your proposed project is not increasing the impact to the soil and other geological conditions, the existing, approved geotechnical report may be valid for the new proposal.
What is required in the geotechnical report?
The report will include written and graphic summary of the subsurface investigation, conclusions or assessment from that investigation, and recommendations for the proposed project. The following items must be included in all geotechnical reports:
- Field Investigation with site plan
- Subsurface Investigation*
- Recommendations for the project/scope of work
- Site plan with landslide prone area overlay, undermined area overlay, and steep slope contours shown (as applicable)
- Demolition plan (as applicable)
- Grading plan
- Professional signature and sealed with liability insurance information
*These subsurface investigation should detail any findings and should include a map that illustrates the investigation. Include site photos if possible.
Who can create a geotechnical report?
Professionals with credentials and who carry liability insurance (individually or as a professional group) may produce a geotechnical report. These include:
- Soil Engineers
- Professional Civil Engineers
- Geotechnical Engineers
- Professional or Engineering Geologists
Who reviews the geotechnical report?
Geotechnical reports are reviewed by the Department of City Planning and by the Department of Permits, Licenses, and Inspections.
Planning staff will evaluate it for completeness during the site plan review. Department of Permits, Licenses and Inspections staff will review it with the building permit(s) to ensure that the recommendations and assessments are consistent with the drawings submitted.
For more information:
For more information about Geotechnical Reports, contact Martina Battistone at firstname.lastname@example.org or 412-255-2516.
For assistance in determining if your project needs a Geotechnical Report, please contact the Division of Zoning and Development Review at email@example.com or 412-255-2241.