Whilst the interiors of this barn conversion in Austria are a little too coldly architectural for my liking, I love this external wall. It evokes a favourite Roger Deakin quote. (It’s also a bit daft that it’s the north facade of the building as the logs will get no sun on them to aid in their seasoning.)

The other thing I always notice with these European conversions is how they would never pass British building regulations – for example, on picture number 10 (the one with a blurry man going upstairs) there appears little if not no insulation in the roof. The budget of 70,000 euros also suggests an ‘unemcumbered’ build.

I was at Rounded Developments last week for a meeting and a big bag of sheeps wool insulation was cluttering the place up. It was a cancelled order that was now looking for a home and fortunately I have a home for it. I have two ‘boxing-in’ projects to complete.

From Barn Conversion 2010

The first is around the manifold and associated gadgetry for the underfloor heating that currently hums away and looks very hi-tech under the stairs, the second is a larger project, to build a cabinet around the thermal store and all its associated gadgetry. The thermal store boxing-in will extend across the width of the second bedroom and incorporate a cabin or built in bed as I’ve discussed previously.

Under the stairs it’s mainly about muffling the sound of the pumps, whilst the thermal store / cabin bed project is a whole lot more complex, with the insulation needed for both sound-proofing and stopping the thermal store from over-heating the cabin and bedroom.

I’d always planned to use sheeps wool for this – I like the idea of the cabin bed being surrounded by nice, warm, natural sheeps wool rather than anything more artificial and harsh.

So far I’m pleased with the sheeps wool as a product – soft and with a pleasant smell, it seems to be just what I’m after. Not sure that the sound insulation will be like and it’s pricey (I haven’t paid for it yet so I’m not entirely sure what it costs) but I’m looking forward to working with it – a job for the forthcoming wet and dark post-pointing days…

A strong yet light insulator, foamed glass is suitable for load bearing applications especially those demanding water and vapour resistance.

Description
Foamed glass insulation is made from (usually) recycled glass that is mixed with carbon and then heated to very high temperatures. Upon heating the carbon oxidises and forms bubbles in the resultant stone-like material. It is usually supplied as a gravel, but is also available in (very expensive) batts.

Features

• High embodied energy. In the glass from which it is produced.
• Renewable . In that it is produced from recycled glass.
• Durable, hard-wearing and able to bear weight. Suitable for roofing in high-load situations such as structural walls, above ground level car parks and green roofs. Ty Mawr lime use it as an insulating moisture barrier in their limecrete floors
• Water and vapour impermeable..

Performance
Typically in the range 0.037 – 0.048 W/m.K. (Watts per meter Kelvin ~ a lower value is a better result)

Cost
With strength comes cost …for gravel at a depth of 100mm, cost is around £15 per square metre or around £150 for a cubic metre bag.

Extruded Polystyrene (XPS) is made by mixing polystyrene and a blowing agent under pressure and then forcing the resultant fluid through a die. As it emerges from the die the fluid expands into a foam, which is shaped before it cools. Extruded is stronger than expanded polystyrene and as such is better suited applications where some load bearing is required such as below ground (for example, in providing an insulation layer in a floor).

Features

• Manufactured from petrochemicals so not sustainable and toxic when burnt.
• High embodied energy.
• Moisture tolerant and relatively durable.
• Versatile, strong and relatively easy to fit.

Performance
Typically has a thermal conductivity or K value in the range of 0.028 – 0.036 W/m.K. (Watts per meter Kelvin ~ lower value is a better result)

Cost
Depending on thickness costs should around £7 a square metre with more specialist flooring products up to £15 a square metre.

Phenolic foam insulation is made by combining phenol-formaldehyde resin (note the presence of formaldehyde, a hazardous chemical and known carcinogen), a foaming agent and a hardener. When all three are mixed an exothermic reaction causes foaming followed by rapid setting.

Description
Usually now available as rigid boards or panels sometimes as a backing to plaster or chip board.

Features

• Relatively low embodied energy – in comparison to similar products.
• Good fire performance. Very low flame spread, negligible smoke emission and very low levels of toxic gas emission.
• Can be cut and shaped accurately. Often used to closely insulate pipes and can be reused.
• Lightweight, strong and durable in higher density applications.
• Can shrink. If applied as a foam then it can shrink when cured.
• Moisture resistant.

Performance
From 0.018 W/m.K, but typically in the range 0.020 – 0.023 W/m.K (Watts per meter Kelvin ~ lower value is a better result)

Cost
Kingspan Kooltherm is available for around £8 square metre.