What can be built on this plot? Feasibility in one conversation.
A client asks what is possible on their land. Instead of gathering the zoning plan, building regulations, ÖREB cadastre, noise map and building register one by one, the AI assistant chains five tools of SPEKTRUM MCP. The result is a first draft of the feasibility study, with a source for every figure and the open points.
The feasibility study is not a tool of its own but a chain of standortanalyse, baureglement_abfragen, vergleiche_varianten, laerm_vergleich and quartier_3d (service bauzone, with ch-bund and the cantonal geodata). It works for a single plot or a perimeter of several plots and replaces neither project design nor the permit.
The chain in five steps
Each step is a tool of its own with its own source. The assistant calls them one after another and combines the results.
- 1
Site
standortanalysePlot, EGRID, zone and noise sensitivity level from the ÖREB cadastre, plus a traffic light for seven topics: planning law, noise, natural hazards, water, nature and heritage, contaminated sites, public transport.
ÖREB binding, thematic maps indicative - 2
Standard building rules
baureglement_abfragenFull storeys, heights, density figure, boundary distances and special rules of the zone from the building regulations that SPEKTRUM has recorded by hand for 917 municipalities.
Working aid, the regulations prevail - 3
Variants
vergleiche_variantenUp to eight development variants against the zero option: floor area, use mix, parking under VSS 40 281 and compliance with the standard rules. Measures are never converted silently.
indicative - 4
Noise
laerm_vergleichRoad and rail noise on every facade against the limits of the sensitivity level, with Art. 22 USG and Art. 31 LSV and whether a noise report is needed.
sonBASE model values, indicative - 5
Neighbourhood and existing building
quartier_3dThe neighbourhood as a 3D model with the plot highlighted in red, a close-up view and figures for the existing building from the building register: storeys, year built, flats, heating. Plus the scenario to 2070.
Working aid
Example Witikonerstrasse 417, Zurich
Plot WI3487 in Zurich-Witikon, 477 m², four-storey residential zone W4, public transport class A, bus 76 m away. Today a detached house from 1965 with 2 storeys and an annex stand on it, together about 323 m² of floor area, 1 flat, gas heating. Real queries of 25 Oct 2026; the variants are assumptions for the example.
| Existing | Variant A | Variant B | Variant C | |
|---|---|---|---|---|
| Development | 2 storeys (1965) | one storey added | two storeys added | replacement with 4 full storeys |
| Floor area | about 323 m² | about 450 m² | about 600 m² | about 572 m² |
| compared with existing | – | +39 % | +86 % | +77 % |
| Floor area ratio (max. 1.2) | 0.68 | 0.94, met | 1.26, exceeded | 1.20, fully used |
| Parking spaces, threshold demand | – | 5 | 6 | 6 |
Floor area ratio calculated as floor area divided by 477 m², simplified with countable floor area equal to floor area; the tool does not silently convert the Zurich floor area ratio into a gross floor area ratio and therefore marks compliance as open. Zone W4 also allows 4 full storeys, 1 roof storey, a building height of 12.5 m and a boundary distance of 5 m, with a length surcharge up to 11 m (BZO Art. 13 and 14).
Further findings
- Noise: immission limit met on all sides; on the street side to the south 62.0 / 54.1 dB(A), only 0.9 dB in reserve, so evidence at the facade is needed. The other sides have 9 to 15 dB in reserve.
- Planning law: no special-use plan, no planning zone, joint development permitted. To clarify are the safety zone and obstacle limitation of Zurich Airport; a new safety zone perimeter is on public display. This decides how high an extension may go.
- Unremarkable: natural hazards, water and groundwater, nature and heritage, contaminated sites.
- Energy: existing building with gas heating; heat demand above the threshold for a district heating network, roofs very well suited for photovoltaics.
- Neighbourhood within 300 m: 211 buildings, 809 flats, 3.7 storeys on average; 61 buildings already exceed the zone measure today, this plot is one of the reserves.
Not part of the study
These questions are needed in addition before the draft becomes a recommendation to the client.
- Economics: construction costs, rents, return and land value
- Private law: easements, land charges and boundary agreements from the land register
- Ground conditions, contaminated site investigation and utilities
- Design, townscape and fit, unless recorded in an inventory
- Municipal rules outside the measure table, such as parking or playground regulations
- The assessment by the building authority: the study is a working aid, not a preliminary decision
What it is good for
- A first assessment for a client before there is a quote
- Acquisition: into the first meeting with solid figures
- Comparing several plots or a perimeter for a site development
- Municipalities: answering «What may I build here?» at the counter
What it is not for
- Building application or permit decision; use the permit pre-check and the authority
- Market valuation or investment decision
- Municipalities without recorded building regulations: the standard rules are missing there, and the assistant says so
How to ask your assistant
One question is enough, the assistant picks the tools itself. In Claude and ChatGPT the site analysis and the 3D model appear right in the chat.
- «What could be built on the plot at Witikonerstrasse 417 in Zurich? Check the site, the standard building rules, three variants, noise and the neighbourhood.»
- «Compare adding storeys and a replacement building with the existing building.»
- «Take the plots with EGRID CH… and CH… as a perimeter and show them in the neighbourhood in 3D.»
- «Summarise this as a feasibility study for the client, with the open points.»
Coverage: site analysis and noise across Switzerland; standard building rules for 917 municipalities with hand-recorded regulations (62 % of the building zone area), indicatively from the cantonal zoning plan for 1,682 municipalities; neighbourhood in 3D fully in the canton of Zurich. Where something is missing, the assistant marks it as «not verifiable».