Green Products Brighten Multifamily Rehab
An abandoned inner-city building gets a second life as a ten-unit affordable cohousing project. What's more, the makeover used green products and materials and energy-efficient building practices and appliances.
In Chicago's south side Woodlawn neighborhood, new home construction, condo conversions,and multifamily rehab are becoming common sights in an area long marked by vacant lots and abandoned buildings. Despite such growth, the need for affordable housing in this neighborhood remains great,as poverty continues to challenge the community, and longtime residents fight displacement from gentrification.To meet this need, an innovative project has grown from a partnership between a nonprofit housing developer and a state agency.
The Woodlawn Development Associates (WDA), a nonprofit neighborhood housing group, completed the rehab of an abandoned 11,694 ft2 three-story masonry building this past February.The building had been abandoned for six years and was in need of major, or gut, rehab.
WDA planned the rebirth of this abandoned building as a ten-unit affordable cohousing project, but it also wanted energy efficiency to be an integral part of the rehab.In addition,green materials and products were substituted for their conventional counterparts. The project was literally topped off with a 2.4 kW photovoltaic (PV) system on the roof.The goal of the project was to plant a green building seed in what is hoped will become a model for future affordable housing rehab in Chicago.Total rehab cost was $792,000 ($79,200 per unit,or $67.71/ft2).
WDA applied to the Illinois Department of Commerce and Community Affairs (DCCA) for a $20,000 energy grant ($2,000 per unit, or $1.71/ft2) under the Illinois Energy Efficient Affordable Housing (EEAH) program. DCCA provides energy grants to nonprofit housing developers to install energy-efficient products such as insulation, air sealing, and high-efficiency heating equipment. The agency also provides technical assistance with its energy grants. According to Henry Kurth,energy manager for the Bureau of Energy and Recycling and administrator for the EEAH program, grants provided to affordable housing developers have resulted in energy-efficient building rehab in over 65 buildings (1,028 units).Annual heating costs in these buildings averaged $227 per unit. That's a remarkable achievement given Chicago's climate. We believe that the energy efficiency measures we utilize in these buildings are proven and should be used in all multifamily building rehabs.
DCCA estimates that annual heating costs for the WDA building will be $2,300 at $0.60/therm (5.0 Btu/ft2 F day), or $200 per unit. They also estimate that annual space heating costs without the energy-efficient building practices would have been $5,700 ($570 per unit),for annual savings of $3,400 ($340 per unit).
DCCA also provided a grant of $25,632 ($2.19/ft2) to cover the incremental costs of selected green building products. The additional cost of the green products represents 3% of the total rehab cost.
In addition, a special grant of $29,720 was given for a 2.4 kW PV system ($12.38/W installed). We felt that the PV system,combined with the energy-efficient measures and the green building products, made a great project that could demonstrate the future of affordable housing projects, said Kurth.The PV system provides power to the common- area panel box.There is no battery storage.
The original rehab plans called for demolition of all interior walls and finishes. New windows and a new roof were included in the rehab work scope,as well as new electrical,plumbing, and heating systems. Fortunately, WDA,its architect (Sam Marts & Associates), and its general contractor (South Chicago Workforce) were all eager to include energy and resource efficiency as integral rehab components (see Partners Create Rebuilt Housing, p. 40).
The EEAH program was established in 1988. Administered by DCCA, the goal of the program is to promote the benefits of lower utility bills that lowincome households enjoy as a result of living in energy-efficient buildings.The program works closely with Illinoisbased nonprofit housing developers to integrate energy-efficient building practices in the rehab of multifamily buildings. Grants are provided by DCCA to help offset the incremental costs associated with increased energy efficiency.
Collectively the energy-efficient building practices included in building rehab are referred to as super insulation (SI).According to Maureen Davlin, program manager of the EEAH program, SI is a package of energy-efficient building measures that we want to see incorporated in building rehab. These measures include high insulation levels, air sealing and ventilation, and high-efficiency heating systems.Developers can't pick and choose the energy measures they want. They have to understand that these measures work in concert with each other. When accepting a grant, they are agreeing to all of the energy measures.
Energy savings have been more than 70% when compared to similar buildings rehabbed without SI building measures, says Davlin.The energy-efficient building practices utilized in the program were described in an earlier issue of Home Energy (see Chicago Apartments Get New Lease on Life, HE Mar/Apr '97,p. 23). The measures are briefly reviewed here.
The inside faces of the exterior walls were framed with 2 x 4 oriented strand board (OSB) wood studs.The framing was placed on average 1 inch away from the exterior wall,providing a wall cavity depth of 4 1/2 inches for insulation. Spray rock wool (with an R-value of 4.13/inch) was installed in the wall cavity for a total insulation R-value of 18.6.By having the framing held away from the wall, the installers were able to spray rock wool between the studs and the masonry wall, creating a thermal break.The exposed brick in the ceiling cavities between the first and second floor and the second and third floor was also sprayed with rock wool.R-43 rock wool was installed in the attic crawlspace. See Table 1 for comments on these and other measures by Dave Sullivan,the general contractor at South Chicago Workforce.
All the windows in the building required replacement. The windows were replaced with double-glazed,lowe single-hung windows by Quaker (Weather Tite series 4050).The frames are aluminum with a thermal break.The R-value of each window unit is 2.88.
A blower door test was conducted of the entire building following completion of rehab work. The blower door was installed in an exterior door opening. Unit doors to the common area were opened and the basement door was closed. The results are shown in Table 2.
Air leakage was also less than 1 inch2/100 ft2 of envelope area and 0.17 CFM50/ft2 of envelope area.A major air bypass typically occurs in masonry buildings where the floor joists tie into the masonry around the perimeter of the building and at interior masonry bearing walls.This bypass results from the manner in which buildings of this type were typically constructed. Floor and ceiling joists were set in the masonry.The subfloor was not installed tightly to the masonry, as the gap between the subfloor and the masonry would be covered by the lath and plaster. Furring strips measuring 1 inch x 2 inches were then fastened to the masonry.Rather than being cut,the furring strips were installed in such a way that they often extend down beyond the floor plane and above the ceiling plane.The air space created when the plaster and lath was installed to the furring strips is continuous along the wall between the basement and the attic crawlspace.
Convective air currents from the basement to the attic crawlspace can be established in this space.The first air sealing measure is to seal this bypass and prevent the occurrence of convective currents within the wall. The joint is exposed when plaster and lath are removed. Workers installed expanding foam between the subfloor and the masonry wall to seal the joint.
The airtight drywall approach (ADA) was used to achieve air sealing in the building.Contractors installed drywall from subfloor to subfloor on the first and second floors,rather than from subfloor to ceiling as is typically done.This necessitates notching the drywall to fit around the ceiling joists where the joists are perpendicular to the wall.The drywall can simply be installed to the subfloor or to the bottom of the joists, without notching,where the joists are parallel to the wall.To further prevent heat loss,we caulked the joint between the top of the drywall and the framing and the joint at the base between the drywall and subfloor.
We installed drywall on the top floor in the typical fashion--that is, to the bottom of the ceiling joists--since the top floor ceiling drywall serves as the air barrier.
Penetrations through the drywall on the perimeter of the units and through the top-floor ceiling were sealed to maintain the integrity of the ADA. This included joints between junction boxes and drywall, joints around plumbing penetrations, and joints between window frames and drywall returns.
We installed a central-heating system consisting of two Weil-McLain GV- 4 warm water boilers.Each boiler has an input rating of 105,000 Btuh and a seasonal efficiency of 87.3%.Domestic water heating is provided by two A.O. Smith Cyclone water heaters. Each water heater holds 60 gallons, with an input of 125,000 Btuh and a seasonal efficiency of 94%. It's interesting to note that the combined input of the water heaters is greater than that of the two space-heating boilers.Water-conserving showerheads along with the fast recovery make this system serve the hot water needs of the residents.
All common-area lighting is fluorescent. There are a total of 24 27W (648 watts) fluorescent fixtures in the hallways and the stairwell that will remain on 24 hours a day. There are seven exterior 27W fixtures (189 watts) that will remain on at night.A 2.4 kW PV system installed on the roof helps meet the lighting load as well as other loads on the common area (such as emergency exit lighting, laundry lights,and basement lights;see below).
The units are equipped with Energy Star refrigerators. Both Magic Chef 18.6 ft3 (CTL1911DEW) and 15 ft3 (CTN1511BEW) models were used in the building.The 18.6 ft3 model is rated at 485 kWh per year with a purchase price of $479 per unit.The 15 ft3 model is rated at 437 kWh per year with a purchase price of $351.
In addition to the energy efficiency measures described above,DCCA provided the funds to replace selected building products typically used in affordable housing rehab with resource-efficient building products. (Resource-efficient products are those that use primary resources in an efficient manner, use recycled and secondary resources, and contribute to a healthy indoor environment.) The goal was to identify resource-efficient building products that might be suitable for affordable housing projects.Incremental costs, product availability, and the general contractor's comments about using the products helped to determine these recommendations.Several other suitable products that we had intended to use were not incorporated into the rehab for a variety of reasons (see Products Not Used, p.38).
We framed the interior of the masonry walls with FrameWorks 2 x 4 engineered wood studs made by Trus Joist MacMillan. The studs look like OSB and may be ordered to any length. Unlike conventional studs,each Frame- Works stud is straight,with no twisting or warping.The studs can be ordered through any lumber supply house.
We ordered wall studs at lengths of 9 ft 8 inches, and top/bottom plate members were ordered at lengths of 24 feet.The OSB studs are denser than a conventional southern pine stud, but this was not a problem, since we were using power saws and pneumatic nail guns.We investigated finger- jointed studs, but they were not available locally.
Rock Wool Insulation
Rock wool is made from rocks such as basalt and diabase.The rocks are heated and spun into fibers to form the insulation. The material is noncombustible and noncorrosive, and will not absorb moisture.The insulation is mixed with a dry adhesive for open-cavity installation. It is mixed with water when installed utilizing a pneumatic spray. Immediately after installation, a stud scrubber is used to shave off the excess insulation,which is then transported back to the hopper for installation. The insulation dried within seven to ten days at the WDA building. The insulation was installed in November and there was no heat in the building.
The installed insulation has a density of about 4.0 lb/ft3 and an R-value of 4.13/inch.The total R-value of the installed insulation is 18.6.In comparison, the R-value of the masonry wall alone is 2.4. Thus, the thermal efficiency of the exterior walls improved by almost a factor of 8.
We used FibeRock drywall (4 ft x 8 ft x 5/8 inch sheets), made from recycled newsprint and gypsum, in the building hallways in conjunction with conventional drywall. FibeRock is about 20% more dense than conventional drywall and should hold up quite well in high-use areas,such as the common areas of buildings like this.However, instead of using FibeRock for the entire wall height,we installed it horizontally and used standard drywall for the upper 4 ft of wall area.This was done to reduce cost. Our reasoning was that the lower 4 ft of the walls would be subjected to greater abuse
FibeRock has no paper face that will blister or bubble should it get wet. It has tapered edges and can be scored like drywall.The surface can be finished in the same fashion as standard drywall.The joint between the FibeRock and conventional drywall is imperceptible following finishing and painting. There was no problem in obtaining the FibeRock.
We caulked joints, cracks,and penetrations in the building with AFM Safecoat. Safecoat is a nontoxic,water-based interior caulk designed to replace traditional caulk for general air sealing. It is not available in cartridges,only in 5-gallon buckets and 1-quart containers.Like any caulk available in buckets, it must be loaded into traditional bulk caulk guns,which must be cleaned.There was no problem in obtaining the caulk.
The Safecoat caulk was used to complete the airtight drywall work. We used it:”
• to seal the drywall to the framing members (top and bottom plates, corner studs, rough-opening members);
• to caulk the base the drywall to the subfloor;
• to caulk the drywall returns to the window frames;
• to caulk the window stools to the drywall;
• to caulk the junction boxes to the drywall;and
• to caulk around plumbing penetrations through the drywall.
We primed the walls and ceilings with Glidden's Primecoat 2000 (now marketed as LifeMaster).This latex primer contains no organic solvents and no VOCs.It is applied in the same way as any primer,dries quickly,and provides a uniform finish.Unfortunately,due to an oversight, the general contractors used a regular latex paint,rather than a low-VOC paint. The primer emitted no odor when drying.There was no problem in obtaining the low-VOC primer.
Wood Floor Finish
Most of the hardwood floors in the kitchen and living areas were in reasonable shape, so we simply patched, sanded, and sealed them with Hydroline, a water-based urethane floor finish, rather than with polyurethane. Hydroline dries faster than polyurethane--so much so that two coats can be applied in one day.The coats are not as thick as polyurethane, so a third coat was necessary.
We installed TerraTraffic tile,a product of Terra-Green Ceramics, in place of conventional ceramic-tile floors in the bathrooms and the front entryway. We also finished the shower walls in three of the bathrooms with the tile. Terra Traffic contains 70% recycled glass. The tile is 3/8 inch thick and is available in nominal sizes of 4 x 4, 4 x 8, 6 x 6 and 8 x 8 inches with trim pieces (outcorners, bullnose, bullnose corners, and so on). Prices ranged from $4.35/ft2 to $8.70/ft2 depending on the color of the tile.
We installed Mohawk carpeting in all the bedrooms. Underneath it, we placed a recycled felt pad made from waste fibers without chemical additives, held in place with tack strips.
The bedrooms were carpeted with Image Stability carpeting, made by Mohawk from PET (polyethylene terephthalate) plastic. The primary source of the plastic used in the carpeting is 2-liter soft-drink bottles from recycling programs.We used tack strips in place of glue.
Because it is inexpensive,the original rehab work called for a vinyl baseboard. We investigated plastic lumber for baseboard, but found it unavailable in a baseboard profile.An acceptable alternative could not be painted. Instead,we installed fingerjointed baseboard and shoe molding. Due to the additional labor costs of painting finger-jointed baseboard and shoe molding, they are sometimes excluded from affordable housing.They are widely used in the rest of the residential building sector.
The rear porch decking and the handicap ramp are made of Trex, a wood/plastic composite made from reclaimed hardwood sawdust and polyethylene.The product can be cut and fastened just like wood. The porches' structural framing, stringers, and threads are made of conventional pressure-treated lumber since plastic lumber is nonstructural.
Medium-density fiberboard (MDF) is usually made from softwood dust or chips that might otherwise be burned or sent to landfills.This represents a good use of a waste product; however, urea-formaldehyde glue is usually used as the binder.The ureaformaldehyde will outgas like many plywoods.This can create an indoor air quality problem.
The interior windowsills, the staircase and entryway baseboard,and the kitchen countertop bases are made of Medex. Medex is an exterior grade, formaldehyde-free panel suitable for applications where moisture may be present.We also used Medex in place of conventional MDF as the substrate for the kitchen countertops.
Reflective Roof Coating
The rehab included reroofing with modified bitumen, which is typically used for reroofing on a building with a low-pitch roof, such as the WDA building.To help reduce the interior temperature of the top floor units during the summer,we applied a reflective roof coating (#608 Aluminum Roof Coating) over the roof.The roof surface has to be very clean for the coating to adhere. It took about one day to apply the reflective coating.
DCCA provided funds for the installation of a 2.4 kW PV system on the roof.The system will provide power for common area lighting and the laundry.The total installed cost is estimated to be $29,720, or $12.38/W.
The PV system consists of four modules. Each module consists of eight 75W Siemens Solar SP75 panels.Each panel measures approximately 21inches x 48 inches and weighs 16 lb. The panel arrays are mounted on a steel rack, installed during the rehab of the building, that is tied to the roof rafters.
Generated power is converted from DC to AC in an inverter located in the basement electrical room.The inverter we selected is model SW made by Trace Engineering. A 2-inch-diameter conduit was installed between the roof and the electrical room.A 1- or 1- 1/2-inch-diameter would have been sufficient for the wires; however,we did not know the wire size until we closed in the building. Consequently, we chose an oversized conduit to ensure adequate space for the wires.
To keep costs down and to avoid maintenance problems, we opted against battery storage.When electricity is being generated, it is fed into the common-area circuitry in place of power from the electric utility. We expect that excess power will be generated that will feed back into the system at certain times. The system is maintenance-free except, perhaps, for occasional cleaning of the PV panels.
As a result of DCCA's efforts, energy-efficient building practices have been included in Chicago area multifamily building rehab for more than ten years. Much experience has been gained, and to a large extent, the inclusion of energy-efficient building practices is accepted by affordable housing developers, architects, contractors, financing partners, and code officials.These practices have repeatedly been shown to be cost-effective and extremely valuable to residents, who need housing that is affordable to live in and not just to build.The goal of the current project with WDA was to ascertain the appropriateness of green building products for affordable housing projects as well as to demonstrate the use of PV in affordable housing. With the successful conclusion of the rehab of the It is hoped that over the next ten years,many of these products and systems will also become proven measures that will be commonplace in affordable housing.
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