How is Building Beneath 'Green'?

One of my mottoes is that "Green is a discussion, not a fact."  I have a little discussion going on in my head around many of the 'green' issues that come up, and will try and share some of it here.  The main big question, of course, is "What defines 'green'?"  Is it the type of material used?  Is it the orientation to nature?  Is it the amount of re-used and re-claimed material?  Is it local (materials and services) vs. non-local?  Is it the 'energy footprint'?  How do we measure 'sustainability'?  Many of these same questions have informed certification systems such as LEED, but I think it is important to ask them again and again.

This is especially important for small (read residential remodels) projects, since all small-project clients I have met are more interested in making informed choices than in certification. 

So, I think about the typical remodeling client, who has the privilege of living in a detached SFR (single-family residence) and wants to add on.  I have to let go of the discussion whether SFR living is sustainable or not, and get down to what kinds of additions which suit this person's needs will be.

Most people who live in detached housing value the small amount of land around their house, so the least invasive types of remodels are vertical additions (building above or building beneath).  The literal footprint of the house remains essentially the same, so the local resources of the homeowner, such as vegetable gardens, chicken coops, dog runs, and ornamental gardens, are not reduced in size.

I believe this makes Building Beneath a very sustainable and 'green' alternative to other types of additions, such as rear-yard, side-yard, and front-yard additions. 

Upcoming Class

FYI, I will be facilitating a class in "Building Beneath" on September 19th, 1-4 pm.  This is through the BEC, 510-525-7610.  An engineer and I will discuss the pros and cons of raising an existing house, or excavating below it, to develop new space, be it for a basic garage/workshop or for a whole new living space/unit. We expect to meet at a real construction site. The cost for this short class is only $45.

Introduction

Have you noticed that there are more and more houses being lifted, for the creation of an addition beneath an existing residence?  At least in the SF Bay Area, there seem to be a lot more 'Building Beneath' projects than in previous decades.  The number of projects that include building beneath, either through raising a house or excavating (or a combination of both), has been rising steadily, though nowadays everything seems slow.  I teach a class on this way of adding to your house at the Building Education Center and am quite interested in this approach.

It seems one of the main reasons this has become more popular is that the structural code restrictions have been getting steadily more stringent in the Bay Area.  Where once we might easily have put an addition on top of an existing house, to do so now requires much more, structurally.  Many walls and most of the foundation below such an addition must be considered carefully and strengthened to suit.  In contrast, if your addition is below the existing house, only the new walls have to meet code.

The corresponding foundation, of course, must also be strengthened, but often the entire foundation is in need of replacement anyway, and many times this is the original impetus that impels potential clients into my office to discuss such an addition in the first place.  Some houses in the Bay Area are still on brick foundations!  These have to be replaced even when building on top or converting an attic..