Often the builder will struggle with grades, this can be self imposed (too high of a roof peak pushes the basement down into the dirt), or due to site condition (natural slope of land). Fighting grades is not a winnable scenario unless massive remedial action is taken. I have been the unfortunate holder of the wallet that has funded such conflicts, and I won the grade battle by losing the cash war.

I wonder if the grade issues you see on site are just poorly designed by someone without enough practical site knowledge, or is it an accident? Did the builder knowingly enter into the project satisfied to manage the grades during the build? If so, this is essentially deferring the problem into the future, yet as the building progresses, it gets continuously more difficult to fix the grades. There are work-arounds to being too low in the ground, but they will be hard, painful, and above all costly.

Here we have a new basement that is ready to pour. The red line is a demarkation of the ‘no wet’ zone. Moisture, dirt, etc, may not sit higher than the red line in order to create a moisture defensible wood structure. The top of the red line also represents the bottom of the stucco drip flashing, or siding, depending on what is used. I dont know of an exterior cladding that can be immersed in wet dirt, thus the grade of the sideyard needs to be a few inches below the red line, preferably that part is gravel, then a landscape fabric, then the dirt starts. The blue line represents the typical adjacent backfill height given existing grades as they pre-existed the project. Clearly this basement cannot be backfilled to the blue line because this results in wet dirt sitting against the wood structure, the grade is above the level of the flooring on the main level of this house.

Solutions are not great here. First of all, a taller concrete basement wall could have saved a lot of grief. That is the first change I would have advised, up front, as soon as the survey marks indicated a cut of 3.1 m, which is too tall (122 inches) and exceeds the height of the formwork. The cost of taller (10 ft) concrete walls is significant, but they are quickly done up front, and allow a much higher safe backfill level. The second option is to build a wooden retaining wall all along the 50 ft length of the house (and beyond to the garage location ultimately). This could be done in combination with a new fence right on the property line. This will be way more expensive and harder to do than taller concrete walls. Another issue is the disturbed ground of the excavation is a terrible place to be building a permanent dirt retention structure because it is settlement prone. Augering and grouting in support posts for a retaining wall in a 4 ft narrow sideyard with unstable fill is not easy whatsoever either.

The second problem is the height of land increases toward the lane, where the garage is. the garage pad will be significantly above the house, making for a much more costly garage pad structure. It makes sense that the back wall of the garage acts as a retaining wall (i.e has frost wall), with stairs down to the yard, and then the wooden retaining wall along the fence line continues to the garage, creating like a deeper but flatter back courtyard. All of this is costly work with equipment, lots of materials and effort, just to create the approximate condition that would have been already freely available on a flatter lot. The garage pad may end up being poured more like a foundation wall than a floating pad, with significant cost and multiple pours to complete that work.

It goes without saying that I looked at purchasing this property and another similar one on the same street, but I didnt bother. The purchase price wasn’t enough in my view to overcome the brain damage likely inflicted upon the builder to deal with the earthworks. There is a good likelihood that the cost to fight the grades will be substantial but the value created by winning the battle negligible. This is certainly an un-winnable fight from the value creation perspective. This project is just beginning so I will take a look at it once it is all resolved to see what they end up doing. Hopefully they have a good strategy to manage these grade problems (not really seeing evidence of this thus far), and a large wallet (remains to be seen for sure but what builder wants to waste a bunch of money). If not, they will be on the receiving end of a brutal construction learning experience.