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 It may be possible to replace outdated central heating and cooling equipment with less expensive and more efficient spot heating and cooling.A Green Gut Rehab Case Study:
MORE ABOUT GUT REHABS
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.
Starting with the bare walls
As difficult as it is to become homeowners in New York City’s perpetually tight housing market, Alicia and David finally managed to purchase a brownstone in Harlem. The trashed and stripped structure needed a complete makeover, including a new roof, new windows, insulated exterior walls, interior walls, and new HVAC, plumbing, and electrical systems. Despite a tight budget, the experienced green design team and actively engaged homeowners created an elegant, daylit townhouse with a spacious kitchen, low-emitting materials, and numerous green amenities.
The goal was a healthy green home.
Convinced of the value of building green, and with David having suffered lifelong allergies, the couple was invested in creating a healthy and environmentally friendly home. Both the contracting team and the homeowners accepted building green on a budget as a design challenge. The team viewed the whole process through the lens of environmental impact, carefully considering energy efficiency, indoor air quality, and environmentally friendly materials. In selecting each product, the homeowners took care to ask whether a greener product could be found.
General design and construction
*50% demolition and construction waste recycling
*Formaldehyde-free batt insulation
*Modular green roof
*Whole-house fan and ducted air-conditioning system
*Kitchen and bathroom exhaust
*Radiant floor heating system throughout
*High-efficiency hot water and space heating, including Flat plate hot-water radiator, which collects solar radiation that heats a coolant, which in turn heats water or the home
*Compact fluorescent lighting
*Energy Star appliances
Wall and Ceiling Finishes
*Bamboo and natural slate flooring
*Low-VOC caulks, paints, and adhesives
*Fasteners (not adhesives) to minimize VOCs
*Zero-VOC clay finish made from reclaimed stone, natural pigments, and soy binder
Furniture and Fittings
Sweat equity cuts costs
Like many homeowners on a budget, David and Alicia did the demolition work themselves. Although the structure was filled with moldy drywall and trash, it was free of lead paint and asbestos; improper abatement of these hazards can pose ongoing problems.
Team and Process
The design-build team and the homeowners worked closely together throughout the project. David and Alicia researched green products.
Location: New York City
Homeowners: Alicia and David Basche
Design-Build Team: Robert Politzer, Hanna Purdy, and
Nick Moons of GreenStreet Construction, Inc.
Area affected: 3,500 ft2
The homeowners knew it would be a challenge to tackle this extensive gut rehab on a budget. How to creatively address budget constraints while achieving their aesthetic and green goals was a major component of the conversation from the start. Their answer to budgetary surprises was to pitch in even more of their own labor, rather than compromise on quality. Partly for this reason, the project took two years to complete.
DRAWING LIBRARY CONSTRUCTION DETAILS
LEED for Homes Gut rehabs are eligible to pursue LEED Home certification; many points are easier to earn, e.g., points in MR2.2 (Materials & Resources) for salvaged materials.
NGBS-Remodel Refer to the ANSI standard and follow the appropriate path based on conditioned floor area involved in the remodeling or addition project and the year in which the original home was built. NGBS