If you’re a hiker, backpacker or sailor you might have studied contour maps to understand your terrain. If you’ve never looked at topography diagrams, you’ll probably find they take a bit of getting used to.
As you’re getting your project started, your architect will be doing a deep dive into all the site conditions. Fitting your building into the terrain is a big part of setting up for the initial design. Their early drawings will often incorporate topography and contour lines that show the existing landscape, studying building siting, slopes, potential site drainage concerns, and so on.
You don’t need to be an expert in understanding contours and surveys, but it is worth getting familiar with what you are looking at.
It’s also worth mentioning that as part of standard architectural contracts, collecting site information from surveyors, along with soil analysis from the required engineers is your responsibility. Your architect can help guide you through this. They will know what information they need to effectively start their design process, and can recommend people they have had good experiences working with.
The surveys they collect describe in detail the landscape’s physical features, including elevation changes, slopes, and natural formations, location of lakes, ponds and streams, as well as precise locations of any built structures. A building doesn’t float freely in space. It becomes part of its surroundings. It should integrate and find harmony with the land. It is a delicate and sensitive challenge. Understanding all of the site information plays a crucial role in determining the design approach for a project.
Understanding Topography: Basics and Terminology
What is Topography?
Topography, by definition, is the physical features of a land area: the elevation, slope, and the arrangement of natural and man-made elements. Architects study topography because the form of the site is important to the design of the building. Even on a perfectly flat site, topography needs to be considered in order to drain water away from the building. Your site is rarely perfectly flat. By analyzing topographical maps, architects can determine the best placement for buildings, roads, and other infrastructure, taking into account factors such as water drainage, soil stability.
Above and beyond making the building look nice, establishing the level of each floor, how the foundations set into the ground, whether any retaining needs to be done, and so on, are all important real world considerations that are part of the design process.
Key Terminology
When discussing topography in architecture, several key terms are frequently used to describe the land’s characteristics and the processes involved in interpreting them.
- Contour lines are one of the most fundamental elements, representing the elevation of the land at specific intervals and providing a visual guide to the terrain’s slope and form.
- Elevation refers to the height of a point on the land relative to sea level, which is crucial for determining the vertical positioning of structures, most importantly the floor and wall plates, and the finished floor elevations.
- Slope, or gradient, indicates the steepness of the terrain and influences decisions on accessibility, drainage, and the stability of foundations.
Other important terms include aspect, which describes the direction a slope faces, and relief, which refers to the difference in elevation between the highest and lowest points in an area.
The Role of Contour Lines in Architecture
Contour lines are the primary graphic tool for drawing topography. A surveyor will measure the site and create a topographical drawing for the architect and landscape architect to use as the base for their design.
What Are Contour Lines?
Contour lines are imaginary lines on a map that connect points of equal elevation above a given level, typically sea level. If you’re looking at a map view of your site, you see how each line represents a specific height, say 5000ft. The line next to it will be the next elevation, up or down (ie. 5001ft above sea level). Most commonly these lines are spaced out at 1’, 2’ or 5’ increments. Steeper slopes have lines that are closer together and gentler slopes have lines that are farther apart.
Interpreting Contour Lines
Interpreting contour lines requires an understanding of how these lines represent the three-dimensional form of the land on a two-dimensional plane. Architects use contour lines to assess the steepness and direction of slopes, identify natural drainage paths, and determine the best location for building foundations. The direction of the slope is perpendicular to the lines. By analyzing contour lines, architects can predict how water will flow across the site, which is crucial for designing effective drainage systems and preventing erosion.
On your project, your architect, landscape architect and civil and geotechnical engineers will coordinate their efforts to design your landscape and grading to optimize the function of your design.
Contour Modeling
These days almost all modeling is done digitally. Early on in the project, your architect will create a model of your site based on the contour maps and surveys you have collected.
In the past, when we built models out of wood, foam board, museum board and various cardboard products, building a contour site model was a fun and labor intensive process with an appealing result. To build this model, you would trace each contour onto a layer of board and cut it out. These slices would then be stacked up to build up the slope, valleys and hills.
Analyzing Topographical Maps for Site Planning
Topographical maps are essential tools in the architectural site analysis process, offering a detailed depiction of the terrain that informs critical design decisions. These maps provide a visual representation of the land’s elevation, slope, and natural features, allowing architects to assess how the landscape will impact the placement and orientation of structures. When analyzing a topographical map, architects look for key features such as contour lines, elevation markers, and natural drainage patterns. This analysis helps in identifying the most suitable areas for building, ensuring that the design takes full advantage of the site’s natural attributes while minimizing potential issues like erosion or water accumulation. Accurate interpretation of topographical maps also aids in the efficient planning of infrastructure, such as access roads and utilities, which must be carefully integrated into the landscape.
Design Considerations for Varying Topographies
Every site has its unique conditions, challenges and opportunities. It is up to your architect to understand these conditions and use them to the best advantage of your project.
On steep terrains, for instance, architects must consider the potential for soil erosion and the need for retaining walls to stabilize the land. Buildings in such areas might be designed with split-level foundations or terraced layouts to follow the natural slope, reducing the need for extensive grading. In contrast, flat terrains offer more flexibility in design but may require careful attention to drainage to prevent waterlogging.
The orientation of buildings is also influenced by topography; for example, placing structures to take advantage of natural sunlight or prevailing winds can improve energy efficiency, glare and comfort.
Conclusion
Understanding and interpreting topography, contours and other site conditions are fundamental skills in architecture. From your standpoint as the client, it’s worth being familiar with the concept so that you get more out of the site plan drawings and presentations. It may look like a lot of lines on a map, but once you take a minute to figure it out, it will all make sense and the drawings will come to life.
