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Green specifying: NBS and green specification

Green issues appear in the NBS in various ways:

• In upfront general guidance to work sections, under headings ‘Environmental issues’ and ‘Health, safety and the environment’.
• In clause guidance, which deals with particular product attributes and cross-refers to general guidance where appropriate.
• In the clauses themselves.

The guidance aims to draw the attention of specifiers to the main issues associated with a particular product or method of construction and direct them to further key sources of information.

Clauses are what usually interest specifiers wanting to meet the green agenda for their project. Sometimes NBS has been asked for the green version of its specifications or for all green clauses to be identified. This presents problems because a product clause may often include a green attribute alongside a more conventional attribute. In addition, of course, green agendas are always project specific – a product that satisfies the green agenda for one project will not necessarily satisfy another. Just to illustrate the point, NBS clauses can be categorized broadly into those that have a recognizably ‘green aura’ and those that are ‘neutral’ until the specifier takes some action.

‘Green aura’ clauses are readily identifiable by their subject or heading, e.g.rainwater/ greywater recycling systems, composting toilets, cellulose fibre insulation, nonhydraulic lime:sand mortar. ‘Neutral’ clauses are those awaiting decisions on clause inserts (e.g. UK sheep’s wool insulation or mineral fibre insulation?) or decisions on clause selection (e.g. timber windows or plastics windows?) to attain the ‘green aura’ in the context of the project specification.

It is easy to get the impression from some designers and organisations that green specifying is something special and set apart from ‘conventional’ design and specification processes. Clearly, this is not the case. Green issues have to be integrated with all the other performance requirements to be considered by the project team such as fire, strength, durability, maintenance, health and safety and, of course, cost.

Integration of green issues within the design and specification process is essential and it starts way back at the project appraisal and briefing stage. This is where opportunities for greening must be raised, unenlightened clients persuaded and a commitment forged. This commitment may, for example, be the pursuit of a BREEAM ‘Excellent’ rating for the project.

Where green specifying is different from conventional specifying, is in the need to make decisions about the green credentials of products and materials and this is where things can get difficult! How do you compare the credentials of one product or assembly against another? Where do you go for information? What is a green product anyway?

Sourcing information

Whereas whole life costing (WLC) of products and assemblies is relatively straightforward, dealing with the environmental impacts using life cycle assessment (LCA) is more complex. Thankfully, for some products and assemblies, the complexities of LCA are simplified by the use of single score eco-rating schemes developed by the BRE (Ecopoints and the green A/B/C rating system). Note the word ‘some’ – relatively few proprietary products have been independently assessed to date under the BRE Environment Profiles methodology, from which Ecopoint scores are derived.

Eco-labelling schemes, such as EU Eco-labels, have a limited range of coverage for products associated with building construction. Thus for many products, decisions on selection have to be made without the benefit of an independently derived green scoring or rating system. There are other information sources and databases to tap, for example those produced by the Association or Environment Conscious Building (AECB). Here, product data may include Ecopoints where the product has been rated or, where it has not been rated, the best available data on its green credentials. However, where there is no independent product assessment, care is needed with manufacturers’ claims about the green credentials of their products. For example, it may be necessary to question how far the product has had to travel (Scotland or China?) or what exactly the nature and proportion of its recycled content is. Common sense is frequently called upon.

Don’t forget that ‘conventional’ product certification schemes such as Kitemarking, CE marking and Agrèment certification can include green attributes. For example, certified products may include waste content either in the form of recycled materials or in the form of secondary industrial by-product waste such as pulverized fuel ash (pfa) in cements and flue gas desulphurization (fgd) gypsum in plasterboards. Of course, as more and more European product and materials standards include green attributes such as recycled content and volatile organic compound (VOC) emissions, green specification will become more straightforward.

Any discussion on green specification and the difficulty of establishing green credentials for products, will often come round to the example of timber and timber-based products. Despite the commitment from the timber trade, environmental organizations and the various certification schemes, obtaining timber from certified legal and sustainable sources is still not a straightforward process. For one thing, certification requires a chain of custody to be established and this is quite a challenge. Also, there are only limited supplies of certified timber which often makes specification statements like ‘all timber to be obtained from a certified source’ unrealistic and difficult to enforce. However, there are actions that the specifier can take. For example, it is possible to seek alternative assurances about the legality and sustainability of timber sources, from suppliers who have adopted an environmental purchasing policy.

For recycled materials or reclaimed components there are several schemes providing guidance and sourcing information. These include BRE SMARTWaste and the Waste Recycling Action Programme (WRAP), which deals with, for example, recycled aggregates and glass. Finally, there is the issue of materials and components arising from demolition and from construction. Ownership is the key issue for determining what is to be done with materials and components arising from demolition. This is a contractual matter. The specification must identify materials and components that are to remain the property of the Employer and state what is to be done with them. The management of construction waste is the contractor’s responsibility. However, the design team can influence best practice by the use of, for example, method statements at tender stage or by appropriate pretender selection procedures.

 

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