Site Plan: the drawing that defines the location of the construction
- Ana Carolina Santos
- Nov 14
- 3 min read
When it comes to architecture and construction, one of the most important (and often least understood) elements is the Site Plan. Much more than just a technical drawing, it is an essential communication tool between the project and the site, between concept and reality. It forms the foundation on which the entire construction process is organised and is also a mandatory requirement in municipal processes in Portugal.
What is the Site Plan?
The Site Plan graphically represents, on a horizontal plane, the exact position of a building or group of buildings on the plot, showing how they relate to their boundaries, streets, elevation levels, infrastructures, and natural elements. It is the document that shows where and how the building will be positioned on the land, serving as a synthesis between the architectural design and the legal, urban, and topographical conditions of the location.
The Site Plan is the point of connection between the architect’s drawing and the physical space where the project comes to life.
Purpose
The Site Plan serves several key functions:
Defines the building’s location on the land, identifying setbacks, alignments, and elevation levels.
Demonstrates compliance with local urban regulations (set by the Municipal Master Plan or detailed planning instruments).
Integrates the project into its surroundings – showing accesses, parking, infrastructures, and exterior areas.
Supports municipal licensing approval as a mandatory component of the architectural project.
Serves as a reference for construction execution, used by the site manager, surveyor, and inspector.
What it must include
A complete Site Plan typically includes:
Property boundaries and adjoining plots (north, south, east, and west).
Existing buildings and demolitions, when applicable.
New buildings with their footprints and dimensions.
Elevation data (natural ground, floor level, and roof height).
Distances between buildings and plot limits.
Pedestrian and vehicular accesses.
Parking areas and circulation spaces.
Technical networks (water, drainage, electricity, telecommunications).
North arrow.
Graphic scale (commonly 1:200 or 1:500).
Legal and regulatory framework
Under the General Regulation of Urban Buildings (RGEU) and the Legal Framework for Urbanisation and Building (RJUE), the Site Plan is a mandatory element of any architectural project. It is used to verify urban parameters such as building footprint, minimum setbacks, floor levels, and façade height, ensuring compliance with the municipal plan and regulations in force. Municipalities may also impose specific representation standards or require complementary documents, such as a georeferenced topographic survey or compatibility with existing constraints.
Technical and urban importance
Accurate reading and execution of the Site Plan ensure that:
The construction is legal and feasible from a municipal standpoint.
The buildings comply with urban alignments and established ground levels.
The design responds appropriately to sun exposure, accessibility, and site drainage.
In summary, it is the key document linking the plot to the architecture, aligning municipal regulations with the project’s design intent.
Practical examples
Single-family house on an urban plot: The plan shows the distance between the house and plot boundaries, vehicle and pedestrian access, septic tank location, and ground slope.
Multifamily building: It identifies mandatory setbacks, surface parking, internal access routes, and technical equipment locations.
Rehabilitation in urban context: It allows verification of façade alignment with adjacent buildings and any necessary corrections.
Practical advice
Request an updated topographic survey before design development to avoid costly revisions.
Confirm with the municipality any applicable setbacks or constraints prior to project submission.
Ensure the plan is signed by the architect and coordinated with all technical designs.
Avoid making changes on-site without prior municipal approval, as they may trigger penalties or project reassessment.
Treat this document as a vital planning instrument rather than a formality.
An accurate Site Plan is the essential starting point for a lawful, efficient, and well-executed construction project.
To consider
The Site Plan is far more than a technical drawing — it is the concrete translation of the relationship between a building and its site. It reflects that the project has been conceived specifically for its context, respecting both its limitations and potential. In legal and construction terms, it is an indispensable tool, enabling municipal authorities to validate project coherence and professionals to ensure its proper execution.
If you are planning to build or renovate, start with the land — and with its Site Plan. The AC-Arquitetos can assist you in developing your project with technical precision and full regulatory compliance, ensuring that every detail of your building begins in the right place.
