More On Site Planning

OK, so my last post ended up being about Site Selection despite being titled Site Planning. Let’s attempt to correct that.

Now that you have your site and you’re ready to begin planning your green home here’s some things to consider.

It has been my experience in construction in general and in green building in particular it always comes down to the money. Sooner or later you’re going to hit the proverbial budgetary wall.

Don’t feel bad, it happens to everyone.

For example, I once had an extremely wealthy client. Once the project was done we had a wrap party. The husband thanked us all, the design team, the build people, suppliers, bankers, etc.

He then remarked that he had given his beloved wife, who had driven the design process, “an unlimited budget.”

and then,

“You wouldn’t think it possible to exceed an unlimited budget but I am here to testify that it is indeed possible and we are standing in the proof”.

But I digress.

No where is the potential to squander money greater than in the so called “Site Development” area. If we can manage this process a bit better we can hopefully have some money left for good windows and extra insulation.

This implies that the building is as small as can be, is relatively uncomplicated and does all the other things proper green design mandates.

Given the larger proportion of total budget devoted to Site Development in residential construction makes Site Development extra important to green house design and construction.

What, you may reasonably ask, is Site Development?

Kind reader, I’m glad you asked.

Many lots do not present ready to build on; we have to make all sorts of expensive moves to get it ready.


Site Development is that list of things that must be done in order to gain access to the site, to connect to utilities, to stage trucks and materials, and, if you must, to retain the earth (the dreaded “Z” dimension, X and Y being the plan dimensions).

Less road and driveway equals less expense as well as less erosion, less loss of precious topsoil, less loss of habitat, less loss of shade, less loss of super valuable native flora, less maintenance, etc.

Pete Seeger sidebar: Why do we drive on the Parkway and park on the Driveway?

Besides the driveway itself an area of special concern is the turn-around or hammerhead. If the lot is steep this feature almost always operates perpendicularly to the lines of topography (translation, it’s going to cost you a lot of money).

Eliminate the hammer head or locate it in an area of relatively levelness and your bank account will reflect the presence of mas pesos – pesos that can pay for exterior insulation, perhaps?

Clarification; suggesting the elimination of the hammerhead should not be read as an endorsement of a circular drive. There are very few instances in the mountains short of the Biltmore House where a circular drive is called for; please don’t do it!

As goes the driveway so too go the length the utilities must be trenched to get to the house. Longer trenching means more money (out of sight – in the ground). It also means more trees potentially damaged, more erosion, more habitat lost, etc.

The takeaway? Reducing driveway length pays in several ways.

If your house placement or driveway design require the removal of big trees you can add this line item to Site Development budget. If the tree’s dripline (it’s outermost leaves or branches) is well away from the area of disturbance (even rolling a tractor over it) there’s one more reason to leave it. Frequently trees are damaged during construction and no one knows because it doesn’t fall right away. Damaging roots near the surface (where almost all of the feeder roots are) sends the tree into a slow decline that only manifest several years later.

By the way, arborists tell me that mature trees are more susceptible to this sort of death by dietary reduction as they are unable to compensate for the nutrient loss as a younger tree might be. The takeaway is to treat matures trees with even more respect that you would a young whipper-snapper.

Is there a place on the road for all the trucks that are going to be coming to your site. If not you’ll have to add some money to the budget for workers to park and for suppliers to lay down material (more Site Development).

Technically the foundation is not a part of the Site Development budget (it might be better placed in the Construction budget of the footprint). In practice the foundation is likely to play a role in the Site Development. Usually one or more walls of the foundation act as “Basement Walls’ that have to be designed to support the back-fill and anything that goes on top of the back-fill (like a super heavy concrete truck).

Using the foundation walls as elements of the Site Development is actually going to be an economical move. You need those walls anyway so the extra reinforcing is minor compared to the cost of a dedicated retaining wall.

A final note on Site Development. Try to avoid retaining walls. They are extremely expensive and they look ungainly if they get above eye level.

If a retaining wall is over 4′-0′ of “unbalanced fill” then the Permitting Authorities are going to require a Structural Engineers seal.

This is a good thing if you have to have a wall over 48″ but otherwise is going to cost you.

Past clients have asked what the big deal with retaining is. After all, they’ve just back-filled 9′- 0″ against their basement wall.

Remember, a basement wall acts as a vertical beam in simple bending, supported at the bottom by the footing and at the top by the floor frame.

A retaining wall is a true cantilever, supported only at the base.

Think of the difference between a flagpole and column and you’ll get the picture.

A final note on retaining walls. If there is no way around them (and often there is no way around them) then it’s worth considering a series of 4′-0″ high terraced walls with level tops. The terraces keep the walls in human scale and provide a place to plant softening plants.

By making the top of the wall level and stepped (as opposed to a sloping top) makes the wall look more stable and provides for a better landscape composition. A sloping top makes the stuff on top appear to roll off (even if it doesn’t actually roll off).

If all this seems a bit much here’s one last piece of advice; consider hiring a Landscape Architect.

In my experience, the fees you’d pay a Landscape Architect are recovered several times over in value added to the project.

This added value is comprised of reduced Site Development cost (often several times the fee), avoided costs (leaving native flora in-situ), avoided mistakes like poorly conceived drainage, and in so-called “repairablility” of the Site Design (is the finished grading going to allow for native landscaping to be re-established?)

Although it pains me greatly to admit, if the choice is between a Landscape Architect and an Architect, and if you have an experienced green builder and if your plan is tight and as “corner disciplined” as possible (more on this next month),  and if your property is steep and/or sensitive you’ll be better off picking the LA.

You might notice that many higher end subdivisions in our area come to the same conclusion…..hiring an LA is a requirement.

You only get one bite at the Site Development apple; make it a good one.

Steve Farrell

Asheville, NC