Facility Deterioration Curve

Every day in the construction business we see situations where preventative action could be taken to make a part of the house or building last longer. In other words, by doing a little fix up now, it could potentially save money in the future. Obviously, not all the opportunities out there to renovate or make an improvement are worth taking. It depends on a cost/benefit trade off.

When preparing to take DCRA’s Property Manager’s License examination, I came across their discussion on items related to this concept.  They talk about important considerations such as physical depreciation (e.g., “physical obsolescence” and “Analysis of Alternative”).  When reading on the subject, I remembered way back to my school days in in my engineering courses and I thought about the concept of the degradation curve. Academic types at the Federal Highway Administration have looked at concepts like this a lot, and it is easy to see taking preventative action at the right time can save a lot of money later down the road, no pun intended!

This degradation curve, whether related to highways or homes, has a similar non-linear shape. In other words, the rate of degradation increases at an increasingly fast rate.  Sounds confusing right? In simple terms, consider carpentry work. When an exterior deck board is installed upside down, it has a tendency to cup the wrong way with the edges upward. (I will blog about the carpentry side of this issue in a future post.) The rain makes the board cup. But, when the board cups with the edges up, then every time it rains, the rain takes longer to dry out because of the cupping. This then causes more cupping and, eventually, it causes board rot.

So, that board that is upside down will rot faster — much faster — because the more it holds water, the more it will hold next time. I know that sounds confusing, but the point is that the (initial) problem is now causing more problems. In this case, because the water caused the board to cup a little, the cupping causes more water to be retained, which, in turn, causes more cupping.


When the highway administration looks at it, it seems obvious: Invest in maintenance and it saves money in the long run. But then the reality of the big picture sets in: A lot of things need to be fixed.  The federal government funds the Highways, and the federal government has a lot of things to fund and fix everyday. Anyone who lives in DC probably has some sense of this because all of our friends and neighbors go to all of the various arms of the government every morning.

It is the same thing in our houses. Each house has at least a short list of things that need to be done. Some of those things are wish lists, others are maintenance. The solution is to make the best choices based on being informed on the condition of your home’s components and taking action at the best time. And, it is important to know that the best time is often early.

The Wardman Home Style

Today, one of my customers told me about his Wardman, and I wondered to myself what a Wardman was. Then I looked it up online and I realized that I live in a Wardman too. Interestingly, as it turns out, the Wardman row home is one of the most common home styles in DC.

Then I found a great article about the Wardman home style.

Underpinning to Avoid Undermining an Existing Footing

When excavating below an existing footing, it is important to take provisions to prevent undermining the footing. Here in the city, this type of scenario occurs commonly when excavating for new additions next to existing structures. Class C & D soils are very common in DC. In soil types like this, an existing footing has an angle of repose that extends directly below the footing and outward to the sides.


Underpinning is the method to support the existing footing to avoid undermining the footing. Different methods of underpinning are available options, but common methods include needle beams, mass concrete, and mini-piled underpinning.

The Rear Ell

The Rear Ell

A lot of the homes in our Capitol Hill neighborhood have a rear ell.  I have been interested in the rear ells for a long time.

The Rear Ell- Marked Up

For one, I thought, initially, that the ells were all built as part of making an addition without underpinning the neighbor’s building, where the neighbor had the “first mover’s advantage” of not having to worry about undermining an existing structure.

But over time, as I became more interested and looked a lot closer, I began to see that so many were built at the same time as the original structures.  This article helps to explain the purpose of the original ells.

Crime Prevention Through Environmental Design

Crime Prevention Through Environmental Design

I thought this was a really interesting article.  A lot of my neighbors, friends and customers have reasonable security concerns.  In addition, although our neighborhood has improved considerably over the past few years, there are still areas and elements of high crime in our neighborhood.

This article includes ideas for smart planning and building/space design to limit and deter crime.