Which Engineering Reports Do You Need Before a Permit?

A building permit application is not a single document but a chain of surveys and designs that depend on each other: the land is surveyed, the ground is investigated, the architectural design is drawn from that data, the structural system is calculated from the ground report, and building services are designed on top. Which documents are mandatory depends on the country, the local authority and the size of the building, but the order and logic are the same in most places. This guide explains that chain and why each link is needed.

Why does the order matter?

Each report is the input to the next. Without a ground report the foundation system cannot be chosen, without the foundation system the structural design cannot be completed, and without the structural design the architectural design cannot be finalised. Skipping the order is the most common cause of design revisions: if the basement or foundation type changes after the ground report arrives, the drawings have to be reworked.

1) Land survey and setting out

The boundaries, levels and existing structures of the land are measured, and the setbacks from the zoning conditions are located on site. This survey is the base on which the architectural design is drawn. On large or uneven land, drone photogrammetry speeds up the survey and delivers a surface model in one pass.

2) Geotechnical site investigation

Boreholes, in-situ tests, laboratory tests and usually geophysical surveys determine the ground’s bearing capacity, settlement behaviour, groundwater level and the site class for seismic design. In many countries, including Turkey, a ground investigation report is required for new buildings at permit stage. The report sets the foundation type and any need for ground improvement.

3) Architectural design

Plans, sections and elevations are prepared, showing compliance with zoning conditions (floor area ratio, height, setbacks). Information from the ground report (whether a basement is feasible, the water table) directly shapes architectural decisions. The architectural design is the reference for structural and services design, so it has to be settled before them.

4) Structural design

Columns, beams, shear walls and the foundation system are calculated from the ground report parameters and the seismic code. The calculation report and reinforced concrete or steel construction drawings are the output of this stage. If a storey is being added to an existing building or it is being altered, the existing structure’s performance must be assessed first, which involves taking concrete cores for strength testing and locating the reinforcement.

5) Building services and other designs

Mechanical (heating, ventilation, plumbing) and electrical designs are drawn on top of the architectural and structural designs. Depending on building type and size, additional documents may be required, such as fire safety, energy performance, lifts, parking or environmental assessment. The local planning authority states which apply; get the list in writing before applying.

Common mistakes

1) Leaving the ground investigation to the end: if the foundation changes, the architectural and structural designs are redrawn. 2) Relying on the neighbouring plot’s report: ground can change within a few metres, and permits require a plot-specific report. 3) Haggling over the number and depth of boreholes: too little investigation creates far greater uncertainty in foundation cost. 4) Commissioning designs from different offices without coordination: column positions clash with the architectural plan. 5) Starting without asking the authority for its current document list: lists change, and missing documents send the application back.

Frequently Asked Questions