Integrated Design: Treating Designers, Builders, and Subcontractors as a Team
Designing together means fewer problems to solve
It’s safe to say that most houses are built the old-fashioned way. It goes something like this: A designer or architect draws up floor plans and elevations for approval by the owners; the plans are turned into detailed construction drawings that can be passed along to a general contractor; the general contractor hires specialty subcontractors, or augments his own crew with subcontractors, and builds the house.
Set your green goals
Everyone is different, so we all have different priorities. For people with asthma or chemical sensitivity, high indoor air quality may be most important. For those on a fixed budget, affordability and energy efficiency may top the list. Still others may make choices based on the ability to grow old in the same house.
While green building and remodeling addresses all of these goals, it's up to the green team to prioritize them appropriately.
The way you plan and design affects the way you build and ultimately live in a home.
Finishes, fixtures, materials, and appliances
Green building is about process first, products second. But the process of building involves myriad products and materials. Green choices offer ways to improve indoor air quality, water and energy efficiency, durability, and comfort.
Paints and finishes on floors, walls, cabinets, and ceilings should be low in VOCsVolatile organic compound. An organic compound that evaporates readily into the atmosphere; as defined by the U.S. Environmental Protection Agency, VOCs are organic compounds that volatize and then become involved in photochemical smog production.. Natural or recycled materials such as wood and tile can provide years of service while looking great. Efficient appliances can save energy and water, and natural lighting lowers the need for artificial lighting.
Know what to avoid in the way of building materials that contain potentially hazardous materials, such as high levels of urea formaldehydeChemical found in many building products; most binders used for manufactured wood products are formaldehyde compounds. Reclassified by the United Nations International Agency for Research on Cancer (IARC) in 2004 as a “known human carcinogen." or carpet cushion made with brominated flame retardants. Older houses should be tested for lead, a common paint ingredient until 1978.
Look for interior finishes that resist stains. Not only will the house be easier to keep clean but there will be less of a need to use harsh cleaners and sealants that are potentially hazardous, especially to children.
Keep indoor humidity at a safe level. Relative humidity greater than 60% can encourage the grown of mold. Dust mites can thrive when the RH reaches 50%. Very low humidity can be tough on flooring and furniture. Generally a range of 30% to 60% is best. A dehumidifier or air conditioning is one sure way of controlling humidity.
Building is a process
Critical gaps in energy efficiency, air quality and durability happen where one trade ends and another begins.
Builder Al Rosetto, of Lancaster, NH says "Indoor air quality begins at the footing." He means that ground water can affect air quality in a basement and not planning for a dry basement when you're pouring the footing can mean a dry basement will be hard to attain. Most concrete contractors don't realize that their work is so important to indoor air quality.
Every trade contractor can improve or diminish the performance of a house.
ABOUT INTEGRATED DESIGN
When the parts fit together, the house is better
The regular way to build is a linear approach that moves neatly from one step to the next. The only problem is that it’s not guaranteed to produce the best result. How come?
Key players may not share common objectives for the project, may not understand how their work affects the work of others, and aren’t looking collectively for ways to make the house more efficient and less costly to build and operate. Have you ever seen a drywaller slash a vapor barrier with a utility knife to make drywall installation easier? Or huge gaps in the wall sheathingMaterial, usually plywood or oriented strand board (OSB), but sometimes wooden boards, installed on the exterior of wall studs, rafters, or roof trusses; siding or roofing installed on the sheathing—sometimes over strapping to create a rainscreen. that "will be covered by siding"? This is where the regular way of building breaks down.
A number of builders who specialize in sustainable design are trying something different. It’s called “integrated design” or “whole-building design,” a collaborative approach that treats the group of people building the house as a team rather than as independent freelancers.
MORE ABOUT INTEGRATED DESIGN
Get the gang together before you start
On large public projects, integrated design can be a time-consuming and expensive process that involves members of the community as well as project planners, engineers, landscapers, and various trade subcontractors.
In residential construction, it can be much simpler. But no matter what the scope of the project, the principles are basically the same. HVAC(Heating, ventilation, and air conditioning). Collectively, the mechanical systems that heat, ventilate, and cool a building., plumbing, lighting and wiring, site planning, framing, insulating and other key parts of the project are viewed as interrelated parts of the whole.
When you're challenging conventional methods, the group has to work as a team
Teamwork is especially important in green building because getting a high-performance house often requires that builders challengeA U.S. Department of Energy (DOE) program to promote the construction of “better than Energy Star” homes. A home must have a maximum HERS rating of 70 to meet Builders Challenge requirements. conventional ways of doing things. Integrated design can include what builders and architects call a “charrette,” a meeting or series of meetings bringing together the designer, builder, and subcontractors to discuss the project and swap ideas.
The word is French, meaning “cart.” According to the National Charrette Institute (www.charretteinstitute.org), its use in this context derives from the practice of collecting work from students at the École des Beaux Arts in Paris in a rolling cart as they worked feverishly at the end of a project.
How a charrette works
However obscure the connection, here’s an example of how a charrette worked on the design of an office building in Pennsylvania, as described by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy.
Designers of the building had proposed using triple-glazed, double low-eLow-emissivity coating. Very thin metallic coating on glass or plastic window glazing that permits most of the sun’s short-wave (light) radiation to enter, while blocking up to 90% of the long-wave (heat) radiation. Low-e coatings boost a window’s R-value and reduce its U-factor. windows, an upgrade costing $15,000. The developer balked until it was also shown that better windows would allow the elimination of a perimeter heating zone, a $15,000 savings, and downsizing heat pumps for another $10,000 in savings. In addition, smaller equipment and ducts meant more space in the building could be rented, adding $5,000 to building income.
The framing is connected to insulation, and insulation to HVAC
On a residential project, huddling up early in the process can lead to proportional savings and better building efficiency. For example, framers thinking ahead to energy efficiency might be more open to advanced framingHouse-framing techniques in which lumber use is optimized, saving material and improving the energy performance of the building envelope. techniques that eliminate unnecessary structural members and leave more room for insulation. More insulation and a tighter building envelopeExterior components of a house that provide protection from colder (and warmer) outdoor temperatures and precipitation; includes the house foundation, framed exterior walls, roof or ceiling, and insulation, and air sealing materials. may allow the HVAC installer to put in smaller equipment. These things are more likely to happen when people talk with one another.
A Systems integration example: building envelope, interior framing and HVAC
On the right is the duct/equipment layout and duct schedule for a high performance home. Note the level of detail, the nice short duct runs with few turns, the coordination between framing and duct runs. This is systems integration of the building envelope, interior framing, and HVAC. How does this happen?
It happens because the architect (or the designer/builder if there is no architect) and the HVAC engineer (or the HVAC contractor/energy efficiency guru on staff, if there is no engineer), believe it or not, actually worked it out together. Neither completed their work alone or in one step. They each refined the systems for which they were responsible based on information the other provided along the way.
The steps involved look something like this:
- Architect: Preliminary design includes:
- Floor joist layout and type
- Proposed locations of mechanical equipment and HVAC distribution system
- Foundation, above-grade wall, and ceiling/roof assembly components, including insulation levels
- Window locations, dimensions, and performance level
- Building orientation
- Rough plumbing configuration (hot water distribution)
- Engineer: make a gross level assessment of the HVAC: location of equipment and distribution system. The engineer may also do a first level energy budget analysis.
Architect: design/specification refinements based on engineer’s comments.
Architect: deliver plan set to engineer, including specifications for building envelope performance attributes:
- Wall framing layout
- Window dimensions and specs
- Air sealing details
- Run first cut design load analysis (ACCA Manual J) to get system sizing for costing purposes. (Optional) Run energy performance analysis with sensitivity analysis on items above, plus HVAC system performance level (REM-Rate, Energy10, EnergyPlus?)
Architect: finalize design attributes.
- Run final design heating/cooling loads analysis, providing HVAC equipment and distribution system sizing requirements (generally based on principles of ACCA Manual S and D), and including mechanical ventilation
- (Optional) Run final energy performance analysis.
Architect: Design/specification refinements. (Including changes to accommodate ducts, venting, equipment placement)
- Architect: Final floor plans showing framing and duct layout
- Engineer: HVAC documentation delivered to HVAC contractor for review and sign-off.
The architect or designer needs to fully articulate the structure, including interior floor framing layout and specifications (i-joists, open-web trusses, etc.) and the HVAC designer needs to fully specify ducts and equipment. If floor framing is left to the framing contractor and duct sizes and runs left to the HVAC contractor to figure out on the job site, the chances of achieving high performance are low, at best.
The result of this systems integration is a high performance home: energy-efficient, safe, and comfortable.
Keeping central goals in mind
“To me, integrated designBuilding design in which different components of design, such as the building envelope, window placement and glazings, and mechanical systems are considered together. High-performance buildings and renovations can be created cost-effectively using integrated design, since higher costs one place can often be paid for through savings elsewhere, for example by improving the performance of the building envelope, the heating and cooling systems can be downsized, or even eliminated. has to do with the planning process and the way you lay out the design for the trade partners who are actually going to do the work,” says Michael Chandler of Chandler Design-BuildCompany that handles house design and construction. Since both services are provided by the same firm, integrated design can often be more easily achieved. in North Carolina. “We integrate the engineering and the HVAC design and the durability design and the space planning and the social planning inside the house and the beauty of the house all into an integrated process.”
The other half of Chandler’s company is his wife, Beth Williams, who is an architect. Together they build three or four houses a year in the Chapel Hill, North Carolina, area. Chandler concentrates on the building science and Williams designs the spaces.
Seven discussions of a good charretteMeeting at the beginning of an integrative design process that sets the stage for cooperation and collaboration among all participants, including the design team, engineers, contractors, clients, and any others involved in the project. Early involvement of the entire project team is fundamental to the successful use of a systems approach to green building.
Because the firm is relatively small, and because they tend to work with the same cast of subcontractors from job to job, Chandler doesn’t use a formal charrette. But, he says, they always start with the same seven elements, what he calls “seven from the start,” that guide the design and construction process:
• Site design
• Resource efficiency and durability
• Energy efficiency
• Water conservation
• Indoor air quality
• Homeowner education (how the house works)
• Global impact
What about builders who don’t have any experience with integrated design? “Be infinitely curious about what makes houses work,” Chandler suggests, “and solicit feedback from your team.” Energy StarLabeling system sponsored by the Environmental Protection Agency and the US Department of Energy for labeling the most energy-efficient products on the market; applies to a wide range of products, from computers and office equipment to refrigerators and air conditioners. and green building guidelines can become catalysts in the process, a place to start.
Chandler also discovered that feedback can be a powerful reward for subcontractors. For example, sharing results of duct testing with the HVAC installer proved to be an incentive to do better on the next house, especially when the “report card doesn’t come with a penalty clause.”
Complex relationships for team and building systems
Eric Doub of Ecofutures Building Inc. in Boulder, Colorado, explains the benefits of integrated design in his company’s “manifesto” this way:
“The complex relationship among building systems and materials in high-performance homes is mirrored in the relationships among the team members. All team members must be able to communicate well with one another, share a common design philosophy, and respect the input of other branches of the team. This high level of teamwork, however, requires a deep commitment from the client to adhere to the integrated design/build process and retail all key players throughout the duration of the project.”
So an explanation of integrated design also can be a pitch to prospective clients on the benefits of choosing Ecofutures as the builder as well as the designer.
“In short,” it adds, “we ask that our clients recognize that we are always acting in their best interest to achieve the best possible outcome: a high-performance, beautiful, healthy home. And since we are the organizational leader in the design/build process it is in their best interest to retain us for the entire duration of the project.”
Keep the Gang Together As You Go
Green design doesn’t end at the charretteMeeting at the beginning of an integrative design process that sets the stage for cooperation and collaboration among all participants, including the design team, engineers, contractors, clients, and any others involved in the project. Early involvement of the entire project team is fundamental to the successful use of a systems approach to green building. ; communication must be consistent throughout the project among all team members. While this can be complicated on a large construction project with many team members, it’s relatively easy at a residential job site. Even small homes benefit from close attention to detail — attention that keeps costs down and quality up.
The charrette process is referenced in many residential building resources and standards, including:
- Canadian Standards Association S478
- ASTMAmerican Society for Testing and Materials. Not-for-profit international standards organization that provides a forum for the development and publication of voluntary technical standards for materials, products, systems, and services. Originally the American Society for Testing and Materials. E 2136
- USGBCUnited States Green Building Council (USGBC). Organization devoted to promoting and certifying green buildings. USGBC created the LEED rating systems. LEED For HomesLeadership in Energy and Environmental Design. LEED for Homes is the residential green building program from the United States Green Building Council (USGBC). While this program is primarily designed for and applicable to new home projects, major gut rehabs can qualify.
- NAHBNational Association of Home Builders, which awards a Model Green Home Certification. Research Center’s Durability by Design
One way to improve communication between team members is by using Web-based quality management tools (see links below under "Further Resources"). They don’t necessarily call themselves QM tools, but they all foster quality improvements by:
- establishing one place for everyone to go to get all information on a project;
- making project information available 24/7;
- making it easier for the entire project team — or for just those involved in a particular aspect of the project — to collaborate;
- making it easy to track actions and assign responsibility for those actions; and
- establishing schedules.
None of these Web-based tools is the magic bullet. They all require commitment by the whole project team, won’t work without a true champion of the system, take time and effort to implement, and are better suited to some types of projects than others. But they can save valuable time, reduce hassles, and be used from pre-design all the way through warranty.
Listening to Industry Leaders
Two leading home building professionals — Paul Eldrenkamp of Byggmeister Design Build, a remodeling firm in Newton, Mass., and Matt Golden of Sustainable Spaces, a home performance retrofitting company from San Francisco, Calif. — have been using Web-based QM tools for several years in their green homebuilding work.
“There is no shortage of these tools on the Web,” says Eldrenkamp. “No system is perfect — many of the ones listed below have their own advantages. Look for systems that are easy to use, have ‘writeboards’ for collaborative work, milestones with assigned ‘ownership,’ and easy upload of all files — including photos, to-do lists, and a calendar.”
According to Matt Golden, “I like to think of these tools as collaboration tools. We use a much more granular, custom tool for actual project management. But Basecamp does a good job reducing our planning and meeting costs. It’s inexpensive and very simple, and all of our teams actually use it.”
To design, specify, and build quality homes, you don’t have to use Web-based QM tools. But they can be very effective at integrating all of the professionals that can make or break your green project — architects, engineers, interior designers, project managers, trades, even the client.
In addition to the tools listed below, another tool that facilitates communication between building professionals, subcontractors, and clients is My GBA from GreenBuildingAdvisor.com.
Integrating Systems for Green Design
U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy
Background on Design Charrettes with Several Case Studies (PDF -- opens in new window)
BC Green Building Roundtable:
Roadmap to the Integrated Design Process (PDF -- opens in new window)
Quality Management Tools
- Don Mannes/Fine Homebuilding 161
- Charles Miller/Fine Homebuilding
- Roe A. Osborn/Fine Homebuilding
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