Tag Archives: Building Envelope

Comfort is key in a passive house

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0620 home green Rendering of the home Chris Weissflog, who operates the renewable energy firm Ecogen Energy, is building for his family. Among other green features, its solar panels will meet most of the 3,000-square-foot home’s heating and cooling needs as well as powering a greenhouse with an extended growing season. With story by Patrick Langston.

0620 home green Rendering of the home Chris Weissflog, who operates the renewable energy firm Ecogen Energy, is building for his family. Among other green features, its solar panels will meet most of the 3,000-square-foot home’s heating and cooling needs as well as powering a greenhouse with an extended growing season. With story by Patrick Langston.

>” […] The falling price of technology may still help us out of the quandary. The CHBA is currently developing a net zero and net zero-ready labelling program for home builders and renovators. A net zero home typically uses photovoltaic panels to produce as much energy as it consumes, generally selling excess electricity to the grid. A net zero-ready home is set up for, but does not include, the photovoltaic system.

The CHBA’s Foster says that a net zero home including photovoltaic panels now costs $50,000 to $70,000 more than a conventional home. That’s 50 per cent of the cost of just five years ago, and the price of PV panels continues to drop.

With rising energy prices, the CHBA says the extra monthly mortgage costs associated with a net zero home are now comparable to the savings in energy costs, making it net zero in more ways than one. […]”<

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Embodied Energy – A Measure of Sustainability in Buildings & Construction

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Embodied energy in building materials has been studied for the past several decades by researchers interested in the relationship between building materials, construction processes, and their environmental impacts.

Source: www.canadianarchitect.com

>” […]

What is embodied energy?
There are two forms of embodied energy in buildings:

· Initial embodied energy; and
· Recurring embodied energy

1.  The initial embodied energy in buildings represents the non-renewable energy consumed in the acquisition of raw materials, their processing, manufacturing, transportation to site, and construction. This initial embodied energy has two components:

  • Direct energy the energy used to transport building products to the site, and then to construct the building; and
  • Indirect energy the energy used to acquire, process, and manufacture the building materials, including any transportation related to these activities.

2.  The recurring embodied energy in buildings represents the non-renewable energy consumed to maintain, repair, restore, refurbish or replace materials, components or systems during the life of the building.

As buildings become more energy-efficient, the ratio of embodied energy to lifetime consumption increases. Clearly, for buildings claiming to be “zero-energy” or “autonomous”, the energy used in construction and final disposal takes on a new significance. […]”<

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High-R20 Concrete Foundation Construction Diagram – Building Science

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This construction strategy has an installed insulation R-value of R-20.

Source: www.buildingscience.com        >” […]

 

  • Dampproofing
  • 2″ XPS rigid insulation
  • Concrete foundation wall
  • 2″ XPS rigid insulation
  • 2″ XPS rigid sub-slab insulation
  • Gypsum board with vapor retarder paint
  • 2″ XPS rigid insulation under slab

Thermal Control:  This construction strategy has an installed insulation R-value of R-20 and has a predicted annual heating energy loss of 16.7 MBtus.

Moisture Control:  Two inches of XPS on the interior, connected to the thermal break at the slab edge, controls the interior vapor drive and capillary wicking to the interior so there are no moisture related issues from inward vapor diffusion or capillary wicking.

Constructability and Cost:  The interior of the insulated concrete form will require drywall or other thermal barrier to achieve the fire rating required by code. The gypsum board is very easy to attach to the plastic clips designed into the ICF. The drywall should not be painted, if it is not necessary, to allow maximum drying of the concrete. It may be easier and more practical to install a thin framed wall (e.g. 2×3 wood or steel framing) on the interior of the ICF to allow any necessary services to be run in the wall, and potentially more insulation.

Other Considerations:  Because the concrete is installed between two vapor retarding layers, it will take several years for the concrete to dry to equilibrium. Since additional interior vapor control should be avoided, no more than latex paint should be used on the interior surface of the drywall. […]”<

 

See on Scoop.it – Green Building Design – Architecture & Engineering

The financial case for energy efficiency

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“The report, Building the Future, has piled pressure on Ministers to act to fix Britain’s badly insulated homes. The report shows that a much more ambitious energy efficiency investment programme would pay for itself and significantly boost the UK economy.

The programme would add £13.9 billion annually to the UK economy by 2030, with GDP boosted by £3.20 for every £1 invested by the Government. A national scheme to make homes super-energy efficient would result in £8.6 billion in energy savings per year by 2030, an average energy saving of £372 per household. After taking into account loan repayments this would result in £4.95 billion in financial savings per year for Britain’s households.”