Eco-Homes Tour

After a very interesting tour around the "Creative Energy Homes" series of Eco-House at the University of Nottingham I feel inspired to write!  The 1930s Eon House is an interesting experiment - taking a  1930s house and constructing it to 1930s standards then upgrading it gradually as a template for the massive task of upgrading the existing housing stock in the UK.  They had to get special permission when building this "eco-house" as its 1930s construction, details and insulation levels did not meet building regulations!  First stage of upgrading was to insulate loft and cavity walls which did not give the level of improvement expected because of the leaky construction - made visible through thermal imaging.  After sealing the floor and other key junctions and installing a more efficient gas boiler the house is now at the level 3 of the Code for Sustainable homes (level 1 being slightly better than building regulations, level 6 being full zero-carbon).  The plan for the next stage of testing and upgrades for the Eon House was explained which was interesting because contrary to what I thought they would do (super-insulate the north wall and build a solar space on the south side), they actually appear to be planning the opposite, with a glazed space to the north using glass with a very low U-value and adding external insulation on the south side.  Answers on a postcard please, or hopefully on their new website, which will be updated soon:

http://www.nottingham.ac.uk/~lazwww/creative_energy_homes/

We got a tour round the level 6 Tarmac home - which shows that a code level 6 can be built from normal masonry and doesn't have to be timber frame.  It also shows an eco-house can be affordable and look like a normal house - whether that's good I'm not sure.  However internally it was very dark because of the controlled amounts of openings to ensure the performance (and cost effectiveness) of the house.  Harks back to the point Tom Dyckhoff was making about light on the program "Secret Life of Buildings" (Channel 4 on Monday) and how depressing it is to live without enough natural light/daylight.  

More successful with regard to this is the BASF House (designed by Derek Trowell) where a sun space on the south side lets light flood in to the open plan living space and two bedrooms above.  The house shows good awareness of solar principles and is also using a ground source heat pump to provide a steady baseflow of warming or cooling and and air source heat pump for a quick response in temperature change or to bring temperatures up or down to the exact required levels.  It is currenly at level 4 of the Code for Sustainable Homes.  The house is apparently a 'passiv-haus' adhering to the german passiv-haus principles of airtightness super-insulation and mechanical ventilation.  It was strange for me to see then that the house is designed with a section suitable for passive stack ventilation with a clerestorey to bedrooms and landing which look like they can vent but regardless let a wonderful cool stream of north light into the property.  BASF's relevance comes through treatments applied to steel brise-soleil (not quite sure how important that is) but more pertinently through the installation of phase-change panels (wax panels cased in gypsum plaster) which modulate the temperature of the space (absorbing the heat when the house is getting too warm and only releasing it when it is cool enough (below its latent phase change temperature).

On the Eon house it would have been good from my point of view (as an architect) to see them introducing some more current/established  methods of upgrading, such as testing external insulation versus internal insulation as I feel these are the solutions that we are currently facing when considering retrofit.  And also considering the scale that retrofit will need to be rolled out across the country a more standardised solution would have been of interest to me.  But I guess I understand that the University perhaps wants to take a more radical approach and am conscious that we need to keep trying new ideas because lets face it, internal insulation is not ideal as you lose internal space and external insulation is not ideal because you change the appearance of the house and have usually have to adjust all window cill details, eaves details etc. because your wall thickness increases so much.

The Creative Energy Homes series of test-bed eco-homes is surely a great idea and provides an interesting coming together of academic minds and industry.  All the houses are fully monitored with up to 160 sensors in one house and the opportunity to tweak, test and implement in a controlled environment should continue to make inroads into how we go about making greener homes.  As a teacher in the same school I can only hope we nurture this opportunity and allow our students to engage with this fascinating program.