Complete foundation package
One coordinated scope: soil data + calculations + drawings + technical substantiation.
Narrow Extension • Foundation Calculations • Soil Investigation
Narrow Extension (Small Rear Extension): foundation calculations, soil investigation & pile plan
Planning a narrow rear extension (smalle uitbouw) and need a safe, municipality-ready foundation design? Aboss provides a complete technical package: soil investigation (grondonderzoek/sondering), foundation calculations, pile plan (palenplan) where required, and the structural drawings/details needed for construction and permit submission.
Amsterdam & region • Insulindeweg 649, 1095EA Amsterdam
Designed for narrow extensions
Optimized for limited width, tight boundaries, and constraints of existing urban buildings.
Clear, municipality-ready output
Practical documentation and details that reduce follow-up questions and delays.
What we deliver
- Soil investigation coordination (grondonderzoek / sondering): planning, scope alignment, and interpretation of results.
- Foundation calculations: bearing capacity, settlement risk, load transfer, and interaction with the existing building.
- Pile plan (palenplan) where required: pile positions, preliminary sizing, pile loads, and structural layout logic.
- Structural drawings & details: foundation plan, sections, connections, beams/steel where needed, and execution notes.
- Municipality-ready technical substantiation: clear narrative + calculation report suitable for permit files.
Typical narrow extension constraints we account for
- Limited width and short spans (but sensitive to differential settlement).
- Proximity to neighbors and existing foundations (risk management and boundary constraints).
- Existing building structure: load paths, openings, and how the extension ties into the main house.
- Execution practicality: access, noise constraints, and construction sequencing for urban sites.
Process (efficient and controlled)
1 — Intake & available information
We review your extension concept, approximate dimensions, photos, and any existing drawings. If there are prior foundation documents or reports, they are highly valuable.
2 — Soil investigation (grondonderzoek/sondering)
If needed, we coordinate the soil investigation and define what is required for the extension foundation design. We then interpret the results in the context of your specific building and site.
3 — Foundation concept & calculations
Based on soil parameters and structural loads, we design a feasible foundation concept (piles/strip/other) and perform the required calculations to substantiate safety and serviceability.
4 — Pile plan and execution drawings
Where piles are required, we prepare the pile plan and structural detailing so the contractor can execute reliably and the municipality can assess the proposal.
5 — Final file for permit / technical review
You receive a complete package (PDF and, if agreed, DWG) for contractor execution and municipality submission.
FAQ
What is a “pile plan” (palenplan) and when do I need it?
A pile plan defines pile positions and load distribution logic for the extension foundation. It is typically needed when soil layers require deep foundations, when loads are significant, or when settlement risk must be controlled.
Can you also provide structural calculations for the superstructure (steel/wood/beton)?
Yes. If the narrow extension includes steel beams, wall openings, or specific structural framing, we can integrate the full structural scope into one coordinated set.
Do you work only in Amsterdam?
We primarily work in Amsterdam and the region, but we also support projects in other municipalities. Requirements can differ per location; we align the package accordingly.
Contact Aboss
Insulindeweg 649, 1095EA Amsterdam, The Netherlands
Tip: send a short description + address + approximate extension dimensions and (if available) photos/drawings. We can then quickly indicate what is required (soil investigation, pile plan, calculations, drawings) and provide a clear quote.