Nov 05

Adding and Using Trees On The Site Design Vignette

Adding and using trees on the Site Design Vignette is important to understand because trees can be used to solve multiple problems when laying out your site design. This vignette really tests your ability as a designer in terms of understanding spacial relationships while solving a variety of programmatic requirements.

This exercise in site planning will typically test your ability to design given different programmatic requirements such as: building placement on the site, views of the site, parking requirements, vehicular circulation, local climate conditions and many more. With so many different requirements given to you in the program, it can be very challenging to come up with a design that satisfies everything.

With so many requirements and restrictions, it’s important to be as efficient as possible with your design. This is why adding and using trees on this vignette is so critical.

What Can Trees Do?

On the site design vignette, adding trees serves two main purposes: to block the sun AND to block the wind.

1) In many cases, certain elements in your site plan are required to be in shade so one of the easiest ways to achieve that is to add trees to help block the sun. Depending on the shape of the element that is to be shaded, multiple trees may be needed to properly shade that element. Elements such as plazas, building entries, or loading docks may be required to be in the shade.

2) The other reason for using trees is to block the prevailing winds on a site. Included in the program will be the direction that the wind typically comes from and in some situations, you will be required to block the wind from specific areas on the site. Similar to blocking the sun, a row of trees may be needed to block winds from reaching public plazas or building entries. Again, this all depends on the specific program given to you so pay careful attention.

Do Trees Have To Be Used?

Depending on the program, adding and using trees may not be mandatory to complete the vignette but I would certainly recommend using them.

In theory, you could use other site elements (such as buildings) to block the sun and the winds from specific site elements. If you choose to use buildings to satisfy these requirements, make sure you are still following all of the other guidelines provided in the program.

Although I’m sure the Site Design Vignette can be accomplished without adding any trees, I don’t recommend it because you’re more likely to violate another requirement trying to block the sun and the wind. By simply adding trees to your design, you can give yourself more flexibility with the rest of the site elements.

The 2 Types Of Trees

There are 2 different types of trees that you’ll be allowed to add on your SPD vignette. Each type of tree has a different function so properly placing the trees in your design is critical.

Deciduous – Deciduous trees are basically trees that lose their leaves in the winter months. On the ARE Site Design Vignette, deciduous trees should ONLY be used to block the sun!

This means that if you are asked to provide shade on a specific site element, use a deciduous tree. If you decide to use a conifer tree, you will be down-graded and could possible fail the vignette.

Conifers – Conifers are much more dense trees that don’t lose their leaves in the winter time. Conifers should specifically be used to block wind on the SPD vignette.

Deciduous trees are not dense enough to block wind on a site so knowing when to place conifers instead is extremely important.

Maintaining Views

One element of the Site Design Vignette that hasn’t been discussed yet is how adding and using trees affects the views from the site. As part of the requirements for the vignette you will most likely need to maintain views from specific site elements. For example, you may have to keep a view of the street from the parking lot.

The issue of maintaining views is important in the placement of trees because the type of tree you select WILL make a difference in whether you can maintain that view or not.

Deciduous trees WILL maintain a view but conifers WILL NOT maintain that view.

Think about it, since conifers are dense enough to block the prevailing winds, they’re also too dense to see through. So if you’re needing to add trees where a view needs to be kept, it’s highly recommended to use deciduous trees in order to satisfy the program.

Efficient Site Design

Just like all ARE vignettes, there is a certain level of efficiency that needs to be maintained in your solution. What I mean by this is that you CAN be penalized for putting too many trees in your solution.

NCARB will certainly downgrade a solution if it’s “over-designed”. I would be careful when it comes to placing trees in your design. It’s important to find that balance between satisfying the requirements of the program and over-designing your solution. In my option, just try to think about your solution in a logical manner and you should be fine with the number of trees you place.

Image Credit to “Solutions” by Norman Dorf

Final Thoughts

As you can see, adding and using trees on the Site Design Vignette is an important factor that many people overlook. Your use of trees in your final solution can certainly give you more flexibility in your design because you won’t be as restricted by some of the programmatic rules. As long as you know how to use trees the right way, you should be just fine.

If you’d like to learn more about the ARE Site Design Vignette, see here!

This vignette is quite challenging because there are so many elements that need to be included in the final solution. By understanding what these various elements are and how they affect the final design, you can save yourself valuable time on the SPD exam. Remember, not only do you have to complete the Site Design Vignette, but you’ll also need to finish the Site Grading Vignette in the same time frame.