What it costs: BREEAM – how to get good grades

All primary school building projects worth over £500,000 and secondary school projects worth over £2m now have to achieve a BREEAM rating of “very good”, which means obtaining 55-70 credits.

BREEAM for Schools considers eight environmental categories and covers more than 70 compliance requirements.

Not all categories score equal points, however. The high scoring categories are energy, land use and ecology, pollution and transport. Although it may not be very meaningful to calculate the maximum average credit per requirement it can provide a useful guide as to where to focus efforts for achieving a high environmental rating.

Lifecycle costing is recognised as a management requirement and can score up to 1.5 credits. Developing a lifecycle cost model early in the design process should enable informed building strategy decisions to be made, such as choosing between passive or mechanical ventilation. Later in the design process, the lifecycle cost model can provide a quantitative tool for component-level specification choices.

You do not get credits directly for reduced lifecycle costs. The benefit seems to be that the lifecycle cost plan provides a tool to appraise the capital and future costs for choices that are governed by other criteria.

Looking at materials: credits are gained for components with an A rating in the Green Guide to Specification (GGS); energy credits are awarded for reduced carbon dioxide emissions; water credits are related to measures that reduce water use.

Achieving credits typically, but not necessarily, results in higher capital costs. The expectation is that reduced operational costs will offset these costs in the long run, but this is not always true. Some sustainable solutions, such as micro wind turbines, result in both high capital and operational costs. The trick is to focus on sustainable options that incur little or no cost.

Material options

There are a number of elements relating to the main components that attract BREEAM credits:

• Floor finishes – where 80% or more floor finishes are GGS A-rated, 1.112 credits are available. Floor finishes should also meet the requirements of the DfES’ Standard Specifications, Layout and Dimensions 2, Floor Finishes in Schools. Typical A-rated floor coverings include linoleum to BS EN 548. Specifiers should not only check the GGS for generic component ratings but also confirm manufacturers’ certification information

• External walls – 0.556 credits go with an A-rated wall cladding, including stainless steel or aluminium panels and clay tiles. Both treated timber and neutrally durable timber cladding attract A-ratings. These may be expected to require replacement at least once in 60 years. Conventional brick-block external walls also offer A-rated solutions

• Roof – pitched roofs with concrete or clay tiles, slate, low-carbon steel galvanized stainless steel or aluminium claddings achieve A ratings and 0.556 credits

• Windows – the moving parts need to be robust. Timber windows to BS 644 and steel windows to BS 6510 would be A-rated in the GGS and get 0.556 credits

• Responsibly sourced materials – structural timber from a sustainably managed source, certified by a scheme such as Forestry Stewardship Council can attract 1.668 credits. Some timber merchants only supply timber from sustainable sources, so a credit here may be achieved at no extra cost.