THE CLOCK is ticking, with the government having set clear targets for buildings to become carbon neutral, writes Ant Wilson, head of sustainable development at Faber Maunsell.
New homes and new schools face a 2016 deadline, public sector non-dwellings need to achieve zero carbon by 2018, and other non-dwellings need to comply by 2019.

But despite these targets, the uptake of renewables and microgeneration is slow – contractors and consultants are still failing to embrace the technology.

So why is the building services industry dragging its heels? One reason is renewables can be expensive. It is, therefore, important to look at renewable energy sources holistically in order to meet the targets in a cost-effective and efficient way.

The first step is to consider the fabric of the building. Before a renewables technology is chosen, air tightness, heat gains and the location of the building all need to be considered.

Energy efficiency

Once the fabric of a building has been improved, and heating and loads reduced, another core area to consider is energy efficiency. With a low-energy, low-carbon building it is far easier and cheaper to reach the local renewables target.

In fact, some argue the best example of renewables is using energy-efficiency measures.

The next step is renewables specification. When it comes to selecting a renewables technology consultant, contractors are cautious.

The location of the project also brings into play another current renewables debate - on whether to opt for on-site or off-site renewables.

Most conurbations have low wind profiles so there is little to be gained from installing wind turbines in a town or city. Therefore, building a large wind turbine plant in a windy location and transporting the power to buildings will give a lower cost per kWh.

Part of the renewables problem is searching for the definitive answer to the zero-carbon conundrums, and selecting the right product. Following the development of each new technology there is hope that this will be the solution. As a result specifiers grab the new technology, only to discover later that it is not ideal for their particular project.

The government has given clear carbon-neutral targets - what is needed now is advice on how to achieve zero-carbon buildings.

New build

And as buildings become more efficient, the ratio between build energy and operational energy is going to change, so the embedded energy becomes more significant. There will be less justification for demolition and new build.

All of which means we are going to have to make much more extensive use of renewable energy sources in the future.

So there is going to be considerably more emphasis on electricity in buildings and a key role for building services engineers is to incorporate more energy generation in buildings.

We can be pretty certain that broader use of solar photovoltaics (PVs) will be more acceptable. In fact, some forecasts suggest that we could be deriving 50% of our electricity from PVs by 2100. For that to happen, the PVs will not only have to become more efficient but also much cheaper.

In the shorter term, there will still be demand for traditional plant such as boilers and chillers, so we need to ensure these are the most efficient available and linked to efficient control systems.

As for new technology, the only certainty for consultants and contractors is that the baseline will continue to move as the government keeps pace with environmental concerns.

The government's pledge to cut greenhouse gas emissions by 80% by 2050 raised the bar - yet again drawing a line under the importance of renewables to our future energy needs.

Now is the time for consultants and contractors to embrace renewable energy sources, because the carbon neutral deadlines will herald the end of traditional building services as we know them.

· Ant Wilson will be on the panel at a seminar on renewables at H&V09 - Feb 24-26 2009