Choosing greener materials

All material choices come with a range of impacts on society and the environment.

Making more sustainable decisions

Anybody involved in specification and procurement needs to find out what these impacts are, weigh them up and reach an informed decision. There is rarely a generic 'right' answer but usually, taking the particular circumstances into account, it is possible to distinguish between the better and the poorer options. WWF has a set of minimum eco-standards by which we assess any product or material before approving purchase.

More sustainable options will usually have some of the following characteristics (many of which overlap):

• Low embodied energy. The sum of energy used in the extraction of a raw material, and the processing, manufacture and distribution of the resulting product.
• Recycled content. Specifying recycled materials can reduce the embodied energy of an item and help solve the problem of waste disposal. 
• Recyclable content. Thinking ahead to the eventual decommissioning of an item can help to reduce its lifecycle impact. Composite and highly processed materials, for instance, can be hard to recycle.
• Renewable material content. Natural biological materials (such as timber, wool, bamboo or seashells) managed responsibly and harvested at a sustainable rate tend to have a much lower environmental impact than mineral alternatives. Although coal and oil originate from life forms, they form over a long geological timescale and cannot be classed as renewable.
• Non-polluting and non-toxic content. In manufacture, installation, use and disposal.
• Local goods. Specifying locally sourced, locally manufactured or locally grown goods reduces transport requirements and can support the local economy.
• Responsible supply chain. For example, a manufacturer with a certified Environmental Management System.
• Durability. This is generally a sustainable quality, except when it arises from over-specification - for instance when specifying a material that will last for centuries but is likely to be disposed of within 20 years.
• Straightforward maintenance and cleaning regimes. Maintenance should be considered when calculating lifecycle costs (both financial and economic).

Natural insulation: sheep's wool
Sheep's wool has excellent thermal and acoustic insulation properties: it even generates heat as it absorbs moisture. It has been used for thermal insulation to a depth of 300mm in the loft and in the new stud partitions for acoustic separation. The wool is a renewable material of course, is recyclable, comes from British hill sheep and was supplied in the form of Second Nature's Thermafleece.

Linoleum - Made in Scotland
In the wet areas of the building, such as the toilets and kitchens, linoleum has been used in preference to vinyl flooring. Linoleum is manufactured in Scotland from natural ingredients such as linseed oil, cork flour and jute. The usual alternative - vinyl flooring - is PVC-based, can contain plasticisers which may be harmful and can give off environmental toxins.

Recycled carpet tiles
The existing carpet tiles in acceptable condition were stored for re-use in the building.

For the new carpet, we found very few manufacturers left in Scotland - and none which manufactured carpet suitable for office use from natural materials. Eventually, a synthetic carpet tile with 80 per cent recycled yarn, from a company with the most stringent environmental management standards in the business, was the preferred option. A large coir mat in the entrance lobby will help to extend the life of the carpets by "keeping the outside outside".

Responsibly-managed timber
Solid wood, certified by the Forest Stewardship Council, was preferred to engineered or processed wood wherever possible. This reduces the energy embodied in the material and reduces the risk of toxic fumes from glue.

Untreated timber
Treatment of timber was avoided throughout, even on the garden fence and posts. Most forms of treatment contain volatile organic chemicals (VOCs), are hazardous to handle and harmful to the environment (soil and groundwater, for instance).

Paints
Sustainability principles were involved in the specification of all internal and external paint. Many standard paints contain VOCs - a range of hazardous chemicals contributing to air pollution and linked to asthma and other breathing problems.

The choice of low VOC paint, preferring natural to synthetic alternatives, reduces the environmental impact in manufacture and the release of toxins during application. One of the decorators benefited from this, as the paint had "no smell at all - which is a good thing because I've got asthma", and the occupants benefit from the better indoor air quality that breathable, non-toxic finishes provide.

There are several manufacturers of suitable paints: we used Keim Paints and Ecos Paints.

PVC-free cabling
Electrical rewiring used low smoke zero halogen cables (LSOH) since standard power and data cables are sheathed in PVC - a plastic with significant environmental impacts in manufacture and disposal, which emits unwanted heat and is a serious hazard in case of fire. LSOH present a much better option. In terms of installation, these cables are a like-for-like replacement for the industry standard PVC variety.

Desks/workstations
The key priority for furnishing the office areas (as with the kitchens, etc) was to avoid new purchases wherever possible. Therefore refurbishment and re-use specialist Ogilvie Ross was recruited to modify and repair the furniture from the Aberfeldy office to suit the layout in the new office.