Cost saving or carbon saving - or does it even matter?

Sustainability and low carbon design are requirements that appear in the brief of most projects in the built environment.

Whether directly from a client's own brief, via planning conditions, regulatory requirements or aspirations of the professional team - the phrases 'low carbon design' and 'sustainable design' are of course morally admirable but what does it actually mean to a client who is paying for the cost of construction? Should the focus be more steered towards running and cost saving – and at the end of the day, does this amount to the same thing?

By way of an example, a client recently provided a brief for a new build project which included extremely low carbon emissions, high insulation values, low air permeability - all the usual criteria that would be considered ‘best practice’ for sustainability.

Once the cost estimate was completed, the scheme came in over budget and a value engineering exercise ensued.Sustainability targets were reduced and the scheme ended up as a compromise, but back on budget. Interestingly running costs were predicted to be higher than the original brief, but still significantly lower than the building that the client was moving from. The client was happy that the scheme was back on track and still very happy that running costs would be a net saving over the existing.

Of course the professional team had to re-design, adding fees and the project program slipped due to the extended design period.

Could this have been avoided? With hindsight yes (and of course this is not an unusual design iteration for a construction project to go through) - but would the client have been better informed to focus on costs in the brief rather than sustainability?

Of course costs are not always the key driver and sustainability is key with some clients. In the Further Education sector, Universities often require class-leading levels of carbon reduction, BREEAM excellent and will tailor their budget to achieve these requirements.

Occasionally a private client will make decisions based on carbon emissions and install (for example) a wood pellet boiler which is more costly to install and run compared to other alternatives. However this is rare and more often than not, costs is the real driver.

So why is cost reduction and minimising running costs rarely mentioned in the design brief or planning design statements? Could it be the case that mentioning money is seen as unsavoury? Undoubtedly planners are more interested in emissions due to environmental targets.

But in our experience most clients want their capital investment spent as wisely as possible and expect that by investing in a sustainable design, they will achieve a low running cost building by de facto, which is generally the case.

In our opinion cost is not a word to avoid as it is often the most important criteria for a project and understanding whether cost ultimately will override sustainability, or the other way around is something worth ascertaining as early as possible.