CSH Level 6 house refurb in Birmingham wins RIBA award
It’s good to see the RIBA awards recognizing low carbon design: John Christophers’ refurbishment and extension of a 2-bed semi-detached Victorian house in Birmingham to CSH Code Level 6 has won a national RIBA Award. The size of the original 1840 house has been doubled by extending sideways into the gap between two houses. The new addition rises two floors plus a studio loft beneath the roof, which is properly oriented for both photovoltaic and solar thermal at the required height to avoid overshadowing.
The open-plan kitchen and dining area is connected to the garden via an unheated, glazed, double-height sunspace which is positioned for solar gain in winter, while a mature ash tree shades the glass in summer. The first floor has a study and three bedrooms, two of which have shuttered openings overlooking the double height living area.
A top-lit central stair is compressed between existing brickwork and new curved walls of textured earth construction.
How they achieved CSH Level 6:
Insulation:
Warmcel 500 insulation is used internally the existing front wall of the house. Insulating wall ties made from basalt fibre were used in the cavity wall.The external and side walls, both original and new, are insulated with Neopor on the outside and then rendered over. Neopor is fixed with special adhesive and not metal or plastic fixings that would compromise its thermal performance.
Apart from the roof, all the walls and floors have between 203mm/275mm/57mm of dense clay blockwork or rammed clay.
U value of walls: 0.11 W/sqm/degC
U value of roofs: 0.08 W/sqm/degC
Windows: Triple glazing with U value of 0.65 W/sqm/degC
Airtightness: The house has been sealed using “Intello Plus” airtight membranes that allow vapour permeability so that condensation is minimised. The achieved Q50 airtightness rating was 0.97 m3/m2/hr.
Heavy construction: Unfired hydraulically compressed earth blocks are used as the main load-bearing construction for the three-storey building.
Low-energy lighting and A++ fittings to minimise electricity use, including an electric cooker with induction hob.
Solar roof: 36 m2 of PV generates about 5150kWh/year.
Solar thermal: Vacuum tube solar panels will provide at least 70% of annual hot water.
Ventilation system: MVHR
Wood-burning stove: Top-up space and water heating fueled by wood from the garden.
Materials
Glaster, a plaster using ground recycled glass bound with lime
Earth-based plaster using natural clay
Floor finishes made from rammed and polished red clay dug up from the foundation excavations on the site
Natural lime mortar
Kitchen worksurface using reprocessed recycled glass
Other features
Energy monitor to display how much electricity the PV solar roof panels are generating, and how much electricity is being used.
Dual flush toilet: 2.6/4 litres
Rainwater harvesting
Plans and partial product listing here.
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Filed under: Eco-projects
Hi,
I am currently doing a dissertation for my final year university project, on looking at converting existing houses to meet the level 6 code for sustainable homes level. I would be very grateful for any additional information you could provide me, about this topic, and any further details on costing, for the above article.
Thank you
David Dobriskey
“Wood-burning stove: Top-up space and water heating fueled by wood from the garden.” - Really? When I had a wood burning stove it would have burnt the wood from an average garden in a couple of weeks, what will they use after that?