About the R-2000 Standard
	The R-2000 Standard
	HOT2000 software
	Whole-house ventilation
	How a heat recovery ventilator works
	Indoor air quality and environmental features
	High-performance windows
	Heating systems
	Engineered floor systems
	Advanced wall systems

Advanced Wall Systems

R-2000 builders use various advanced wall construction systems that improve the performance of the home and conserve natural resources. These systems are the result of ongoing research that involves materials manufacturers, the home building industry and government.

Here are some of the new systems being used today by R-2000 builders.

Advanced Wood Framing Systems

Traditional houses are built with vertical wall studs spaced about 40 cm (16 inches) apart. The size of the studs is determined by the load characteristics of the house and by the need for specific wall thickness to accommodate insulation. Because lumber comes in only a few standard sizes, many exterior walls are overbuilt, wasting wood.

Advanced framing uses wood studding that precisely matches the design needs of the house, by adjusting the distance between studs. As a result, and as the industry moves to metric measures, wall studs may be spaced 50, 55 and 60 cm apart (20, 22 and 24 inches, respectively). This saves wood and reduces the amount of thermal bridging caused by studs, which are less resistant to the movement of heat than the insulated wall area.

Insulating Concrete Form (ICF) Systems

This relatively new wall-construction system doesn't use wood. Instead, the wall is constructed from insulating foam blocks that are filled with steel reinforcing and concrete. After the concrete is poured into the pre-moulded forms, interior and exterior finishes are applied, and the wall is complete. This wall solution offers several benefits: high levels of energy efficiency, no settling or wall movement, and a lot less outside noise penetration than with frame systems.

Panelized and Modular Construction

Some R-2000 builders use factory manufacturing techniques to build homes. Panelized systems involve large sections of wall that are fabricated in a factory and assembled on-site. Finishing, pre-wiring and pre-plumbing are often done during the manufacturing process, so site construction is fast and efficient.

Modular construction goes a step further – the entire home is built in a factory, in sections that are shipped and assembled on-site. A home may consist of any number of modules, and virtually any house design can be built this way. Site assembly of a modular home takes only days.

The advantages of either factory building process include increased capacity for quality assurance during construction and the protection of the unfinished house from rain or snow.

Airtight Drywall Approach (ADA)

In most homes, the movement of air and moisture through exterior walls is controlled by an air/vapour barrier – usually polyethylene sheeting – installed behind the drywall. Some builders use a different technique – the airtight drywall approach (ADA) – which involves a rigid air barrier.

With ADA, drywall, sub-flooring and other structural elements in the home are carefully sealed together to reduce air leakage. Wall and ceiling surfaces are then painted with vapour-diffusion-retardant sealers to prevent moisture from passing from the interior of the home into wall cavities. ADA construction is particularly effective in areas that experience high winds.

Structural Insulated Panels (SIP)

Structural Insulated Panels (SIPs) are panels that have a core of rigid foam insulation between an exterior and interior skin. The most common materials used for the skins are structural oriented strand board or plywood. The foam cores consist of expanded polystyrene, extruded polystyrene or polyurethane. The two skins, in combination with the integral insulation core, carry all of the loads of the structure. The foam core keeps the two skins aligned, acting as a web, and provides the insulation value.

The advantages of structural insulated panels are:

• they are energy efficient
• installation is fast
• the walls are straight and smooth for the interior finishes and exterior cladding

Further information on alternative wall systems for low-rise housing is available from the Canada Mortgage and Housing Corporation

R-2000 is an official mark of Natural Resources Canada.