Understanding a Residential High-Performance Building Envelope - A Guide

A high-performance residential build starts with an advanced building envelope. Technology backed by science has allowed us to build efficient and sustainable homes. The building envelope uses a combination of components to manage a home's heat, air, and moisture to improve its efficiency, comfort, durability, and the health of everyone who lives there.

A high-performance building envelope is designed to reduce heat transfer into and out of the structure. This decreases cooling loads during the summer and heating loads during the cold Wisconsin winters.

New construction is the best time to install a high-performance building envelope. While it is possible to upgrade the envelope of an existing building, it can be costly. However, an exterior renovation can also provide an excellent chance to improve insulation and airtightness.

Let's look at the elements that go into creating a high-performance building envelope.

First, The Benefits of a High-Performance Envelope

A high-performance building envelope reduces heat gain in summer and heat loss in winter. During the summer, an efficient envelope reduces electric bills because the load on the HVAC system is reduced. Winter savings are varied since heating systems use a wide range of fuels.

A high-performance building envelope can reduce the upfront HVAC cost in new construction. Because loads are reduced in a high-performance environment, the capacity of the equipment can also be reduced. This can reduce costs and also lower long-term maintenance costs.

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An efficient envelope can also increase protection in extreme weather events that result in power loss. An airtight, well-insulated building can sustain temperatures longer than a building with a less efficient envelope.

The Steps to Create a High-Performance Building Envelope

The goal of a high-performance building envelope is to control the flow and movement of air across building components. This involves selecting and integrating components that control temperature, moisture, and air quality. The primary elements of a high-efficiency, high-performance building envelope include insulation, air barriers, vapor barriers, and weather barriers.

Insulation Materials

Proper insulation is a primary element of an energy-efficient envelope. Various materials offer distinct properties and advantages. Common insulation materials include:

• Fiberglass: Lightweight and easy to install, fiberglass is a cost-effective option offering good thermal resistance.

• Mineral Wool: This is made from rock or slag fibers. Along with insulating properties, mineral wool is fire-resistant and has soundproofing qualities.

• Spray Foam: Spray foam offers the best thermal resistance. It expands to fill gaps and cracks, creating a highly efficient air and vapor barrier.

• Rigid Foam: Rigid foam offers a high R-value and is often used for exterior sheeting or continuous insulation.

Air Barrier Materials

Air barriers are crucial for controlling airflow into and out of a structure. An efficient air barrier can prevent drafts, heat loss, and reduced energy efficiency. A successful air barrier must be continuous, airtight, and durable. An air barrier system must ensure that all potential leak points are properly sealed. Barrier materials include:

• House Wrap: Synthetic and vapor-permeable, house wrap is installed around the house to create a continuous barrier.

• Sheathing: Rigid sheathing panels can be made of plywood, OSB, or rigid foam. They can function as an air barrier and offer structural support.

• Sealants: Joints and seams must be sealed. Caulks, tapes, and foams work to prevent air leakage.

Vapor Barriers

A vapor barrier is used to control the moisture throughout the building envelope. Vapor barriers help to prevent condensation and prohibit mold growth. Common materials include:

• Polyethylene Sheeting: Durable and cost-effective, poly sheeting is typically used as a vapor barrier in walls and floors

• Vapor-Retarding Paint: Specialized paint that provides a moisture-resistant layer on interior surfaces.

• Foil-Faced Insulation: Rigid foam or fiberglass batt insulation with aluminum foil facing that acts as a vapor barrier.

• Installing a vapor barrier depends on the building construction type and the local climate. In a cold climate like here in Wisconsin, the vapor barrier is installed on the interior side of the insulation.

Weather Barriers

In a high-performance building envelope, the weather barrier protects the building from water penetration, wind damage, and UV radiation. Common weather barrier materials include:

• House Wrap: Wraps provide a vapor-permeable layer around the house.

• Building Paper: Asphalt-saturated felt provides a breathable moisture barrier.

• Liquid Barriers: These coatings form a seamless water and air-resistant layer that allows vapor to pass through.

Durability and Improved Air Quality

A high-performance building envelope is constructed from materials that resist wear and damage from environmental factors to ensure long-lasting coverage. Proper installation is essential to maximizing the building envelope's lifespan. At Degnan Design-Build-Remodel, we use materials that are highly resistant to moisture, rot, UV radiation, and structural stability.

A well-designed building envelope helps to provide the occupants with a healthy indoor environment by controlling airflow. With effective barriers, you will prevent drafts, reduce moisture accumulation, and minimize outdoor pollutant infiltration. An efficient vapor barrier will control moisture and, when combined with a ventilation system, will reduce the risk of dangerous mold growth, allergens, and other pollutants.

At Degnan Design-Build-Remodel, we understand the science behind a high-performance building envelope. Each of our designs addresses the challenges of thermal bridging, leakage, and moisture control. Our builds implement solutions that deliver our clients optimal performance, comfort, and durability.

If you're considering a new addition or remodeling a kitchen, bathroom, or basement, let us help you create a high-performance building envelope and design the perfect finished space! If you live in the Greater Madison area, call the experts at Degnan Design-Build-Remodel at (608) 846-5963. We can take your home to the next level of comfort, design, and function! Ready to learn more? We're always happy to answer your questions.