Respect the Original, Reuse What You Can, and Update for the Next 100 Years
Tearing out everything down to the studs offers lots of green options.
Gutting a building down to its frame can be a good green way to get a fresh start while the walls, floors, ceilings and roof are opened up. Questions about insulation, air sealing, and utilities disappear once you can see everything. A green rehab should focus on bringing the interior up to contemporary standards for form and function while honoring how the building has survived.
During demolition, consider reuse, recycling and land fill options for all the materials that are removed from the house.
Look for the hidden gems, and beware of the hidden hazards
Reusing materials is normally a great strategy for conserving resources, but only if the result is a high-performance building — energy- and water-efficient, durable, and healthy. Environmental quality is a paramount concern both during and after a gut rehab because many older buildings contain hazardous materials.
Consider integrating existing elements into the new design
Old buildings tend to have many layers, so it’s easy to miss some of the gems from the original design that might be brought back to the surface. Not all older buildings have historical architectural features that are worth preserving, but it’s worth exploring the possibility.
Check for contaminants
Old buildings often conceal contaminants: lead paint, asbestos, mold, pesticides, and coal dust. Finding out whether they are present, and safely abating them may require the help of a trained professional.
Search out moisture problems
Larger air leaks are usually obvious, and therefore easy to identify and fix. But older houses may have many smaller air leaks that are difficult to detect. In a drafty house, such leaks may cause building materials to dry out more quickly. But if a house is tightened up and insulated, the moisture equilibrium may be disturbed.
Integrate mechanical systems into the new layout and structural framing if possible
Opening up floor plans can change the dynamics of heating and cooling. Mechanical systems can also be affected by the orientation of floor framing, the dimensions of interior walls and chases, and the locations of bathrooms and kitchens. Create a plumbing core in the new floor plan by "stacking" bathrooms, kitchens, and laundry rooms. A more efficient building envelope may allow for smaller or less heating and cooling equipment and more efficient duct and plumbing runs. It may be possible to replace outdated central heating and cooling equipment with less expensive and more efficient spot heating and cooling.
More About Home Offices
Design strategies for a gut rehab should include minimizing demolition and construction waste, choosing more durable materials, installing an effective air barrier, and testing for hazardous materials. If existing ductwork is reused, seal it off to keep it free of contaminants during construction.
If necessary, install a radon mitigation system. Insulate the floor slab and foundation walls.
Control bulk moisture--the flow of water through holes, cracks, and other discontinuities into basement walls. Air-seal the building carefully. Superinsulate the walls from the inside or outside, and use formaldehyde-free insulation. If necessary, replace existing doors and windows with energy-efficient versions. Minimize materials with advanced framing practices, and specify the use of FSC-certified framing, sheathing, and siding.
Design mechanical systems for efficient distribution. Specify high-efficiency appliances. Avoid ozone-depleting refrigerants. Vent all combustion heaters.
Reconfigure plumbing to distribute hot water efficiently, and insulate hot-water lines. Consider an on-demand, tankless water heater.
Image Credits: Julia Jandrisits/REGREEN, Robert Politzer/REGREEN, Mark Piepkorn/REGREEN