straw bale houses: advantages and disadvantages

Straw bale walls can be built quickly and easily… This, and environmental concerns (straw bales can save around 20% of the wood necessary to the construction of conventional residences) has fueled some popular enthusiasm for straw bale home construction. But there are also common concerns about straw bale construction.

Straw bale is an attractive alternative to wood framing. Straw bale homes don't differ much from wood-frame homes, except on the walls.

Straw bale walls advantages

Straw bale walls provide super insulation (the R-values of their walls are the double or the triple of traditional homes), making them excellent for both cold and hot climates...

'Straw bales are particularly cheap, and the wall construction doesn't require specific skills (it's a DIY job).

Straw bale modular nature allows a faster wall construction and a flexible design: deep windows, deep overhangs, curves...

Note on straw bale windows: In hot climates, windows should be placed on the inside of the wall (thick bales create thick walls), to get a deep shadow around the glass. In cold climates, windows should be placed on the outside of the wall, to get more sun...

Concerns and realities: Humidity, rodents and insects

Straw should be kept dry, both on the construction time and after it. Without proper procedures, straw will rot. Straw bale walls should remain breathable, and protected with good anti-moisture barriers.

Pests such as termites do not thrive on straw bales. The dense bales also don't allow space for rodents and other larger pests.

A well constructed straw bale home is extremely resistant to damage from fire, dispelling common concerns and believes.

Hay fever and allergies aren't truly an issue; bales will not release anything into the home, since the walls are completely covered by stucco...

Avoid straw bale construction in damp, humid climates.

Straw bales can last for many decades, as long as water doesn't leak into cracks in the walls. Ordinary rain and moisture will not damage the straw bale walls, but extreme rain conditions and damp, humid climates will damage.

And improper wall construction may indeed be a cause of rotting problems. You should allow the wall to breath, and extreme cares should be taken at this level and in terms of maintenance.

Prices

Though straw bale construction techniques are simple and relatively easy to put in practice, final costs of walls (including the sealing and plastering of the walls) are very similar to those of conventional homes (roughly, the cost of the walls accounts for 15% of the total cost of a house).

Bale application is easy, but since walls are thicker and require a larger top plate and larger foundations, there is often slightly higher construction costs at this level.

Besides, there is also the cost of sealing/plastering both sides of the walls – a crucial element to prevent the straw riot – which exceeds that of standard construction.

Local legal barriers

Local authorities, insurance companies and banks are increasingly open to straw bale home construction. But it still exists some barriers concerning local building code approvals, mortgages, insurances and bank loans.

You should contact your city or county building code officials, and your state energy office for information on local codes and energy codes.