Sustainable Building

A growing awareness of climate change, rising energy costs, and adverse health consequences of traditional construction practices, are changing consumer demand.  The building industry is currently responsible for nearly half of the green house gas emissions in the US. Consumption (burning) of fossil fuels is by far the most significant contributor to climate change, non-renewable resource depletion, and toxic pollution. However, a constantly changing marketplace, pushed by demand and regulations, have helped to create better building practices and products, which are utilized in offsite construction.  The opportunity to utilize these new practices and products through offsite construction offers the developer a more efficient, cost effective and schedule friendly solution while still leaving the homeowner with a better, healthier, more cost effective, high performance home.

In the United States, buildings account for:

• 36% of total energy use/65% of electricity consumption
• 30% of greenhouse gas emissions
• 12% of potable water consumption
• 30% of raw materials use
• 30% of waste output/136 million tons annual
• 38% of total green house gas emissions

This level of consumption is largely due to the standard practices and processes used in site-built construction.  Traditional on-site building wastes more material, delivers a less energy efficient product, and produces far more vehicle trips.  This excessive waste and energy consumption, while acceptable to some, will quickly become a way of the past, leaving the developer stuck with a less cost effective, schedule effective and lower performance building.

Off-Site Construction answers the need for more efficient design, more efficient production, and more efficient delivery.  The sustainability principles that we hold ourselves to, in order to deliver a sustainable, efficient and cost effective building are as follows:

1. Conserve energy and water
2. Maintain healthy indoor air quality
3. Minimize the use of toxic and hazardous materials
4. Reduce Waste - reuse, recycle, reduce
5. Use renewable, sustainably harvested natural materials, and consider biodiversity protection
6. Minimize pollution of air, land and water
7. Encourage environmental stewardship by suppliers and manufacturers
8. Ensure durability

Following these principles allows us to ensure that we are serving the developer, the homeowner, the community and a larger environmental cause.  However, this principles alone are not enough to distinguish us from the building community at large.  These principles, paired with the numerous advantages of off-site construction methods, puts us in a unique position to offer a sustainable construction project that offers a cost effective, high performance building.

The following are factors which justify off-site constructions methods:

1. Reduce Energy Usage and Greenhouse Gas Emissions
   When designing for sustainability, the objective is to reduce and conserve the energy consumed in a building. 
   
   Air infiltration undermines the best building insulation. By minimizing air infiltration, a warm, draft-free indoor environment is delivered, with lower operating expenses, reduced equipment sizing and reduced green house gas emissions.  The building industry in the US is responsible for half of the green house gas emissions.
   
   In addition, in order to have an efficient home, the building envelope must be extremely high performance.  Excellent insulation, paired with minimized air infiltration equals a more cost-effective and energy-efficient home.  The use of SIPs in off site construction insures continuity of insulation throughout the building envelope.  SIPs completely eliminate air pockets that are prevalent in on site construction using loose fill insulation.  This reduces the risk of condensation which increases the thermal effectiveness of a building insulation and nearly eliminates the risk of mold.
   
   High Performance Homes built off-site often perform up to 70 per cent better than traditional site-built construction built to code. Off-site construction is more air-tight which provides improved thermal efficiency, lower operating expense, and reduced green house gas emissions.
   
   
2. Efficient Building Process
   Off-site construction is built more efficiently to quality-controlled standards with high-performance components, using well trained workers with a high degree of repetition.  In addition, up to 67 per cent less energy is required to manufacture off-site construction compared to traditional site-built construction. (source: Arup Research and Development). This is realized in a number of ways, one that is a very clear example of cost savings and energy savings is transportation.  Off-site construction generates up to 90 per cent fewer vehicle trips to the site (source: Mtech), which offers clear environmental benefits, as well as reducing congestion and disruption during construction.
   
   A factory has a more efficient building process than a construction site. Lifting equipment enables materials to be handled in larger quantities than on a building site. Advanced CNC cutting machines are used in the production of panelized walls, floors, and roof components, improving accuracy and further reducing waste.
   
   Conditions in the factory are significantly improved compared to a building site that is exposed to the elements. Skilled staff work in a controlled environment, without bulky clothing, which helps to ensure construction quality. On a building site, workers get wet and cold, which decreases quality and increases material waste, product damage, and reduces recycled material.
   
   Material wasted through damage and deterioration is significantly reduced. Material storage is under cover in controlled factory conditions.  Workers are not subcontracted labor.  Factory personnel are permanently employed, well-trained, and  highly skilled. 
    
3. Minimize Waste
   There is pressure on the construction industry to greatly reduce the material waste going to the landfill. Construction waste currently comprises between 20%-40% of landfills in the United States.  In addition, nearly 5% of construction budget is usually dedicated to hauling waste.  Off-site construction can reduce on-site waste by up to 90 per cent. This is because much of the work takes place in a controlled factory environment, which enables waste segregation and recycling.  Buildings are erected using prefabricated components which also reduces waste.  Overall, this translates to both cost savings and reduced environmental impact.
   
   Factory Staff are trained to recycle.  Materials are segregated using color-coding at the factory in an effort to recycle most waste.  Materials such as plastic, cardboard, wood, metals, and pallets are separated for recycling.
   
   Material efficient design, careful engineering, and smart selection of materials help reduce waste in the manufacturing process. Using CAD/CAM Software, we are able to produce panelized components using a digital fabrication methodology that employs computer controlled cutting, milling and nailing equipment. This process allows a direct translation from a three dimensional digital model to prefabricated components, ready to assemble rapidly at the factory.
   
   
4. Life Cycle Cost Analysis
   Life cycle cost analysis is central to sustainable construction.
   
   The use of advanced building simulation software enables a detailed environmental analysis to be carried out for every project at the earliest design stage. This is a powerful tool that can assess the impact of specification decisions on capital cost, energy consumption, green house gas emissions and operating costs over the life cycle of a building to produce the most sustainable design solution for each project.
   
   We combine the design process with advanced computer simulation techniques to analyze building performance tuned to local environmental conditions and consumer preferences. Mass producing sustainable, affordable and desirable housing is realized. The issue of sustainability is growing ever more important and construction may have the greatest impact. Off-site building methods produce more sustainable buildings and minimize impact on the environment.
   
   These benefits are further enhanced through the use of automation, vertical integration, and information technology tools that integrate design, engineering, and production.
   
   

Conclusion

A more sustainable approach to construction can add considerable value to a building project. The use of modern methods of construction, such as off-site building systems and prefabricated components, can help architects and developers achieve their sustainability objectives with the benefits of cost, speed, quality and efficiency.

Off-site construction offers developers the unique opportunity to improve both efficiency and sustainability.