Insulation

An important starting point for insulation is the energy code.

The New York State 2020 Residential Code has adopted the 2018 International Residential Code (IRC). The R-value requirements for wood-framed walls from Table N1102.1.2 of the 2018 IRC for Climate Zones 6, 7, and 8 offers two options—R-20 cavity insulation plus R-5 continuous insulation or R-13 cavity insulation plus R10 continuous insulation. Notice that both options require continuous insulation.

Passive House requirements for Climate Zone 6 are more stringent:

Wall: R-39 to R-51

Roof: R-70 to R-90

Slab: R-28 to R-40

I plan to use foam sheathing, probably Polyiso Insulation, on the exterior side of the wall and roof structures. Below are some guidelines for ratio of R-Value for these panels vs. the total R value of the walls (based on the nominal value of the insulation layers, without taking into account the effects of thermal bridging through the studs) from Green Building Advisor

The same article has guidelines for roofs:

If the roof has an R-Value of 80 for Passive House, the Polyiso insulation must have an R-Value of 45.

This is a thorough discussion by IDI Distributors of different types of insulation for metal buildings.

Atas International from Allentown PA makes insulated metal wall and roof panels and has good information

This Guide to Insulating Sheathing from the Building Science Corporation has good information. Costs of 1-in thick 4 ft x 8ft panels of insulating sheathing:

Discussions about Spray Foam Insulation

4 Pitfalls of Spray Foam Insulation on the Energy Vanguard blog.

Spray Foam insulation is generally considered to not be green by many, including Phius, but I am intrigued by BioBased 1701s, which is a water-blown spray foam insulation which yields an R value of roughly R-6 per inch.

Ecohome has a discussion comparing different kinds of rigid insulation

Insulated Metal Panels may be a simple solution but not so clear on the cost. 4 inch panels from Centria provide R-31. Here are the details for wall panels

InSoFast is an interesting product that includes studs within the insulation to prevent thermal bridging when attaching. Their 2 1/2" panel has an R value of 10 and "studs" on 16" centers (which are not structural, however).

Polyiso Insulation seems a good eco-friendly and budget conscious choice. Here is the Environmental Product Declaration

Hammer & Hand Construction has great wall details and discussion of Passive House insulation approaches.

The below looks like a detail similar to Hammer and Hand walls that could be used for Metal Panels.

Green Building Advisor has the following info:

• A good post about metal siding over exterior continuous sheathing.

• A post about installing furring for rainscreen cladding over insulation. Code apparently requires that siding over insulation be attached through to the studs but this post on Building Science Corporation's site indicates that attachment to furring only can be done as an alternate with engineering.

• A good post about insulating a cathedral ceiling roof. The same 51% rule of R value for exterior insulation applies, so if I am aiming for an R-80 for Climate Zone 6 the R value of the exterior insulation needs to be greater than the inside (say R45 for the outside and R35 for the inside).

Green Building Advisor recommends a vented roof for Climate Zone 6. MBCI has a good post about this for metal roofing.

I like the idea of using Larsen Trusses with Cellulose Insulation.

Wikipedia has an exhaustive discussion of Cellulose Insulation, including discussion of Spray Applied Cellulose for new construction.

Building Science Corporation has a detailed article on using insulation panels as exterior sheathing.

For underslab I am considering Perlite possibly in combination with polyiso or other conventional insulation. See this white paper from the Perlite Institute

Understanding R Values

ColoradoEnergy.org has a great table of R values of many materials

ASTM C518: Standard Test Method for Steady-State Thermal Transmission Properties

Standard: ASTM C518 – Standard Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus

Scope: This test is used on a wide range of materials.

Applicable Products: Insulation, construction materials, window materials

Test Procedure: This test uses a Heat Flow Meter Apparatus (HFM). The Heat Flow Meter consists of a cold plate and a hot plate which incorporate heat flux transducers for measuring heat flow. The material to be measured is placed between the two plates which are controlled to different temperatures to create a heat flow from hot to cold plate, which is measured by the transducers. The device is calibrated against materials of known thermal conductivity and can be used to measure flat materials in a wide range of thickness and conductivity. Tests are commonly performed with a mean temperature between 35ºF and 110ºF, with the most common being 75ºF. A temperature difference of 40ºF – 50ºF is commonly used.

End Result: The thermal conductivity (k-Value) and thermal resistance (R-Value) are determined. These values can be used to determine energy losses through a material. This test can be used to satisfy R-Value regulations for insulation materials, such as the US Federal Trade Commission’s “R-Value Rule” (10 CFR 460).

Special Notes: This method can often be used as an alternative to ASTM C177, which determines the same properties using a different device known as a Guarded Hot Plate Apparatus (GHP).