We’ve decided against the LEED system as it is by far and away the most expensive and seems to emphasize the business angle a little too much. I do like that it covers the house building process quite holistically, including considerations for landscaping and proximity to community amenities. However, requiring certified specialists in most every sub-category to externally validate design adds up very quickly, and undermines the expertise of the architect who has been thoughtfully selected to head the design of the project for just those very qualities. The expectation being, that when additional expertise is required, then she should consult to fill in the gaps.
It also seems quite product oriented and serves mainly as a vehicle for expensive products to be brought to the marketplace that possess ‘green’ qualities more as a branding angle as opposed to truly being a simple, elegant, regional solution, which to me is more what green design is about.
For what it’s worth, I think there is value in using the system as inspiration but the costs outweigh the benefits, as far as we’re concerned. We’re planning on staying in our home for life and don’t need the marketing cachet that a LEED stamp could bring.
That leaves us with EnergySTAR, GreenHouse, and Green Globes, neither of which are perfect, either, but provide guidance at a cost of an order of magnitude less. They don’t have the same sort of trend-setting cachet but as I said, we’re not here to sell the house, but to live in a comfortable home that tried to tread lightly during construction and will require minimal inputs for its maintenance and running throughout its long lifetime.
We’re leaning towards GreenHouse as it bases its energy efficiency component on EnergySTAR and hits key holistic green building principles. In terms of advice regarding selecting environmentally preferable materials and products, I find Alex Wilson’s review of new products interesting reading.
Similar projects: List of residential housing projects that have similar goals to ours (previously noted, but collated here for easier reference)
After going through the various checklists, here is a run down of our green building priorities.
#1) Must Haves
Energy & HVAC
1. Passive solar design: adequate thermal mass; super-insulated air tight building envelope; high quality windows to minimize the need for back-up heat; exterior shading for windows to prevent overheating during the summer. Slab, basement walls, above grade walls and roof must all be very well insulated and minimize/eliminate thermal bridging.
2. Ventilation: eliminate need for A/C by ensuring windows placed for cross-ventilation; maximize stack effect and allow for warm air to escape through operable high windows or skylights or vents; energy efficient whole-house fan
3. Energy efficient systems & appliances: energy recovery ventilator; drain water heat recovery system; induction stove; appliances (can reuse EnergyStar fridge, dishwasher, washing machine, dryer)
4. Masonry heater
5. Thermal comfort throughout the house
5. Ceiling fans: as necessary to promote air circulation and increase comfort
Lighting
1. Daylighting: maximize natural lighting throughout the day and year to minimize the need for electrical light throughout the house
2. LEDs: plan for use of LEDs where not completely cost prohibitive
Water
1. Low-flow toilets, faucets, shower fixtures
2. Grey water capture and use: capture grey water for use in low-flush toilet, irrigation of green roof
3. Rain water capture and use: capture rainwater from roof for use in as many applications as possible
Resources/Materials
1. Low impact materials: low VOC paints and adhesives; select for reused products/content, recycled content, local, low-maintenance and durable, certified and/or local wood for construction and finishes
2. Design construction to minimize waste and thermal bridges: Advanced framing, use of pre-engineered wood products, SIPs for roof perhaps? ICF or Durisol for below grade walls
3. No area carpets
4. Partial green roof: for thermal and sound insulation properties, reduction of heat island effect, esthetics
#2) Would be nice if we can find it in the budget
Energy & HVAC
1. Hydronic back-up heat in basement and upper level
2. Some sort of air or ground source heat pump or a simpler system of an air intake to precondition air
3. Phase change drywall to contribute to thermal storage
Water
1. Rain water capture and use: install cistern, install filter and sterilizer so water could be used for additional household uses, even as potable water perhaps?
2. Minimal water use toilets: dual flush perhaps, a urinal in the powder room maybe? compare composting toilets to super-low water use dual flush toilets
3. Permeable paving
4. Instant hot water recirculation pump with a proximity sensor
Resources/Materials
1. Minimize use of polystyrene
2. Use exclusively FSC wood products
3. Use exclusively regionally sourced products and materials
4. Minimize use of portland cement by substituting other materials such as fly-ash into concrete, or alternative dry-wall products that reduce portland cement content
5. Green roof for entire roof surface except areas reserved for future solar PV panels and rainwater capture
#3) Extra frills
Energy & HVAC
1. Allow for battery storage for eventual PV hook-ups
Water
1. Faucets with sensors, i.e., no touch controls
Materials
1. Life cycle analysis available for majority of materials selected and select only for those that can demonstrate long-term durability, sustainable processing/maintenance/recycling/reuse throughout product life cycle.
January 22nd, 2010 at 5:53 pm
[...] well if we’re at the model stage. Kris has a post up over at her blog about some of the green certification systems we’ve been examining and synthesizing (and by “we,” I of course mean “her”) over the past few months. In redux, [...]