Eco-houses
Another 'staple' of the practice has been one-off private houses. Some are self-built, others self-commissioned, contractor-built.
Each has its own brief, constraints and opportunities, and we use our experience and skills to draw out from the client:
• what they really want
• what they really need
and, finally
•. what they can really afford
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These were all designed to the client's brief and budget
Case study : Accessible Eco-house, Monmouth
A 164m2 house, commissioned autumn 2005, completed summer 2007.
​
The initial brief was for an accessible eco-house, and was designed in line with the AECB silver standard, which stresses the importance of highly efficient building fabric over ʻhigh techʼ add-ons.
Solar hot water was incorporated, and photo-voltaic panels added in 2010. The result is very low energy use, compared to national averages:
Eco-design features
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passive solar design
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avoiding over-heating
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minimal ʻthermal bridgingʼ through the fabric
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super insulated roof
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super insulated walls
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super insulated ground floor
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high performance joinery
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high airtightness level
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mechanical ventilation
glazed south-facing lounge
canopy to bay window
by careful detailing
+ site-work
300mm insulation
250mm insulation
150mm insulation
by Nordan, Gloucester dependent on build quality central without heat recovery
Other design features
The briefʼs excellent accessibility was guided by the Lifetime homes standard. The wheelchair lift is unusual, but shows how a new house can be made 100% accessible at modest additional cost.
It also called for good natural light, and views of the existing gardens.
Materials
Conventional materials were chosen for
• client preference +
• buildability by conventional builders
Although materials with higher embodied energy, it was judged that this would be well outweighed by the buildingʼs very low lifetime energy - an approximate 10% / 90% split
Construction Details
ROOF
• natural slate + battens
• 350mm I-beam rafters
• 350mm insulation
• air control layer
FIRST FLOOR
• Ê»Eco-joistsʼ to enable ducting
• central ventilation system
• conventional flooring+ plaster
WALLS
• plaster +self-coloured render
• concrete block cavity wall
• 250mm full-filled cavity
GR. FLOOR
laminate wood flooring
underfloor heating
super-insulation
concrete beam + block
conventional foundations
Lessons from the build
Overall, eco-design thinking has moved on since Ty Gwyn was designed e.g the spread of the superior, more rigorous Passivhaus standard.
The following lessons are shared:
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procurement from committed eco-builders is vital...
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work must not proceed until overall cost is established...
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design instead to the now tried and tested Passivhaus standard...
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achieve excellent airtightness through careful site work + supervision...
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use better high performance windows next time... !
Using ʻleading edgeʼ thinking in 2005, the resulting house is a light, attractive, warm, comfortable, accessible, energy efficient + pleasant home.
Eco-houses, Herefordshire
2 self-built eco-houses on the outskirts of Hereford, with superb views over the Wye Valley.
Substantial 3-storey homes with a number of eco-features. Built 2007-8
Eco-houses, Forest of Dean
A development of 8 eco-houses, self-built by a community self-build group, Pioneers Self Build, and managed by Gloucestershire Housing Association.
The design followed the principles of community self-build developed by architect Walter Segal in the 1960's, using a lightweight timber frame.
Eco-cottage, Forest of Dean
A private house built in 1985 as a 'replacement dwelling' of a corrugated-iron clad pre-war bungalow in the Wye Valley AONB.
This was designed with higher levels of insulation than required at the time, and maximised the floor-space within the permitted building footprint.
The client still lives there, happy and cosy, some 40 years later, with a couple of additions.