Housing Authority (TNHA)
Wow! The TNHA/CCHRC Northern Shelter, thirty (30) home, new construction housing project achieved completion of the first seven (7) homes with a 6 Star Building Energy Efficiency Standards (BEES) rating (Point Lay, Anaktuvuk Pass) on the North Slope. BEES Standard scores ranged from 95.3/100 to 97/100. The AKWARM software indicated use of 140 gallons of heating oil per year, which is better than the preliminary annual usage estimate of 146 gallons that was prepared from the plans… and much better than the NSB average of 859+ gallons per year.
A reduction in heating oil usage of 83.71% or, to put it a different way, the new BEES six star homes will use just 16.29% of the heating oil used by the average North Slope home!
We are confident that the next ten (10) in Kaktovik and Nuiqsut (completion in about 4 weeks) will rate Six Star with a BEES standard score near 98/100 with further improvements we have incorporated.
Congratulations to all of the TNHA staff. Well done!
Daryl V. Kooley
Chief Executive Officer (CEO)
The TNHA Sustainable Housing Project Phase IV house is framed with an integrated wood truss, a single prefabricated unit that combines the exterior walls, floor joists, and roof framing into one structural assembly. This creates a thick cavity that allows ample space for high R-value insulation and speeds up the process of framing construction.
The entire envelope is filled with 10 inches of polyurethane spray foam, which is airtight and moisture resistant, for an R 60 rating (3 times higher than a conventional 2 x 6 wall). Steel siding provides shear strength and prevents moisture from infiltrating the building. (CCHRC, 2014)
Most homes on the North Slope rest on wood pilings driven into the ground. This accelerates permafrost thaw by conducting heat into the frozen ground. As the permafrost thaws, the ground around it settles. The prototype has a post-on pad foundation that rests atop the ground, isolating the house from the soil and preventing heat from affecting the permafrost. With the threat of permafrost melt and intensifying coastal erosion, the foundation incorporates beams that act as skids designed to facilitate easy relocation of the house if necessary.
In order to further mitigate environmental impact, the foundation has sliding steel posts attached to pads which may be adjusted up or down to accommodate variable movement or irregularities in the building site of up to 8 feet. This also has added benefit in that absolutely no gravel or invasive site preparation (i.e. clearing, fill, earthwork) is required for the new home construction. (CCHRC 2014)
Lifewater ExtremeSTP ® On-Site Residential Sewage Treatment System
In recent years village sanitation has expanded beyond “honey buckets” and high maintenance flush and haul systems to include multimillion dollar utilidor systems and sanitation treatment facilities. On the North Slope of Alaska connection to existing utilidor systems is either unavailable or is cost prohibitive. Low-maintenance, affordable alternatives must be found and utilized. TNHA has implemented Lifewater Engineering Company’s “custom built,” proprietary, above ground or below ground ExtremeSTP® residential sewage treatment plant as the preferred solution to this problem. The above ground units are specifically designed for areas where permafrost, bedrock or other ground or soil conditions make it impractical to install a below ground system. Lifewater’s residential ExtremeSTP® sewage treatment plants: Will operate at -60oF (-53oC), provided reliable electrical power is available; will not corrode and never need painting; can be sized for aircraft transport to remote northern communities; utilize submerged fixed film activated sludge aerobic sewage treatment unit; utilize UV disinfection; include an effluent pump; and, the $30,000 systems use minimal electricity and do not disrupt the delicate Arctic tundra and permafrost. Lifewater systems require very minimal service every 6 months.
The TNHA Sustainable Home designs all incorporate the Lifewater Model SST600 self-contained, DEC approved, sewage treatment plant at per unit average cost of $39,000 as opposed to utilidor systems costing several times that figure. (CCHRC, 2014)