Landscape Design: Site Analysis and Evaluation
Every landscape design process begins with a thorough site evaluation and analysis of existing conditions. Based on these findings, a landscape architect can make preliminary decisions about features that will be incorporated into the master site plan and those that will be changed or deleted.
Landscape Master Plan
Once we understand what we’ve got to work with, we can sketch out concepts that we know are buildable–based on known characteristics of the site. The landscape architect then produces a rendering that is the equivalent of a homebuilder’s construction drawing. This landscape master plan details all aspects of the design and shows how multiple-use areas will function together to make a balanced, cohesive outdoor living environment.
The Blank Slate
When your landscape architect walks a property for the first time he will note strengths and weaknesses in the topography. He will make special note of
- location of utility services
- orientation of the residence
- prevailing wind direction
- sun and shade on site
- changing elevations & grading
- surface and groundwater
- soil composition
- condition of trees and plants
The first questions I ask when I stand on a new site are: where is the water coming from, where is it going to go and what’s going to happen when it gets there? Howard Cohen, Registered Landscape Architect
Drainage & Grading
Drainage is almost always an issue and a consideration of high importance at the outset of any Northern Virginia landscape design project.
In designing and constructing the hardscape features (patios, retaining walls, walkways) we use grading to control the direction and velocity of surface water. The landscape architect can mix permeable surface areas with buried drainage pipes and retention wells to allow water to percolate naturally back into the soil.
The landscape in Fairfax County is overbuilt. That causes drainage issues. The soil doesn’t drain because there’s a lot of clay and rock in the area. Chad Talton, Registered Landscape Architect
We use Fairfax County soil maps to help us anticipate issues on-site, but never really know what we may find until we start excavating. We may find the soil needs amendments because the original earth has been removed and replaced with backfill.
In addition, the architect’s design plan will need to conform with county and community zoning restrictions, storm sewer easements, septic fields, flood plains, HOAs, and resource protection areas (setbacks off tributaries or bodies of water).
Site Topography: Grading & Elevations
Depending on the goals of the landscape design plan, we may use steps and terracing to create varying elevations on a flat site. This helps us define use areas and add variety to the landscape.
We could decide to alter a slope by removing earth and using that as fill to make another area more level. Retaining walls are often used to contain sloped areas or to cut into a steep grade to create a flat area.
If it works for the landscape style, we may use boulders instead of a retaining wall. That allows us to integrate vegetation with built materials so it becomes a living wall.
Sometimes the most creative approach is to use what is already there. In the case of the ridiculously steep grade at the rear of this Vienna, Virginia home, we decided to go with the (downhill) flow. Click the tabs below the image to view before and after.
The natural-looking stone and boulder work in this design cleverly disguises the wall systems and terracing of this steep slope. Now the slope resolves naturally at the edge of a lagoon-style swimming pool with a rocky diving ledge. Click here to view photos of swimming pool designs in Northern Virginia.
The same principle of “use what you find” can be applied to a flat site. Rather than reshape the grounds, the architect used built structures to transform the approach to this Great Falls Virginia home.
The cedar gates and stone privacy walls add visual variety and define entries. The transition from street to home has become a pleasing, “welcome home” experience.
Follow the Sun
The landscape architect’s understanding of sun and shade patterns on the property will determine the type, size, and location of plant materials to be installed. When the hardscape is being designed we are leaving room for the plants to grow and spread to their proper size. If we don’t leave enough room for the plants, the area will be a mess when they grow in.
Site Analysis Underpins the Design
“Analysis” and “evaluation” isn’t sexy, but it is essential. As landscape architects, we want to fully understand what works and doesn’t work on the property. It gives us a place to stand so that we can create. With that foundation, we can confidently move earth, move trees, create focal points, frame views, and make a place outdoors where you’ll want to spend a lot of time.
Did we answer your questions about the importance of site planning in landscape design development? Is there anything else we ought to have covered? If you’ve been thinking about investing in a landscape design project, our eBook: Expert Guide to Planning the Landscape Design of Your Dreams, is full of valuable information to help you get started.