Energy scares lend weight to Part L

Energy demand management is becoming increasingly pivotal as power supplies dwindle, according to Jeff House, Marketing & Applications Manager at Baxi Commercial Division.

The recent cold snap that plunged the UK back into wintry weather, just when we thought spring had arrived, put our energy security problems into sharp focus. The surge in demand for heating fuel in the run up to Easter exposed the fragility of our critical energy infrastructure as it emerged we had just two weeks of gas supplies available as temperatures plunged.

During the very cold winter of 2010/11, we had a similar scare when Centrica warned the Government that it was just about to run out of gas. Thankfully, we then had the warmest January and February on record and disaster was averted.

However, it is increasingly clear we can’t keep riding our luck. The chief executive of energy regulator Ofgem warned the industry last year that things were looking bleak. Alistair Buchanan told the CIBSE Annual Lecture that, although the Government’s long term energy strategy might be sound; the short to medium term situation was alarming.

“The UK’s power demand is falling, but our capacity is falling faster,” he told the Institution’s members and guests.

Wakeup call
Mr Buchanan explained that the country is running out of energy because renewable power generation was moving “profoundly slowly”; the programme to build nuclear power stations was delayed by funding problems; and the carbon tax (in effect from this April) would put coal-fired power generation out of business.  He recently repeated these dire warnings to a national audience on Radio 4’s Today programme – quite a wakeup call!

In the next two years we will lose 11% of our power generating infrastructure as more coal and old-style gas-fired power stations are closed down as we seek to meet our legally binding commitments to cut CO2 emissions.

This government has a clear vision of a low carbon replacement by 2030, which looks achievable, but in the meantime we are going to struggle. Renewables currently account for less than 10% of our needs and we have just one new gas-fired power station under construction, which is not due on stream until 2017.

Energy buyers are also scouring the planet for gas supplies to keep our remaining power stations operating as our own North Sea stocks dwindle. It is going to be very expensive if we become hooked on imported gas – whether piped in, fracked or liquefied – but we will have to pay the price or face power cuts.

With time running out we simply must get really serious about the demand side and start using considerably less energy – without huge strides in conservation we cannot close the energy gap.

Fortunately, as the cost of energy soars, the business case for energy efficiency improves. Buildings are responsible for over 40% of total energy demand so residential and commercial building occupants will see their energy costs rocket in coming years.

Underpinning the economic driver for energy conservation are the changes to Part L of the Building Regulations, which come into force in October. Taken together, economics and legislation can deliver the profound changes needed to the way we manage energy use and heat our buildings. 2013 is looking more and more like a pivotal year for energy efficiency.

Part L 2013 has, sensibly, taken a more flexible approach than previous versions to make it easier for the building services industry to deliver a broad programme of low energy buildings.  It has set a range of target improvements of between 11 and 20% (compared with the 2010 version of Part L) for new non-domestic buildings depending on the type of structure being constructed. The Government hopes this will make it easier for design engineers to produce solutions across a wider range of buildings and, therefore, deliver an overall improvement of between 15-18% for new build.

If legislators had insisted on a blanket 20% improvement they could have made the cost prohibitive for some types of building, potentially leading to a reduction in build rates.

To achieve the most energy efficient solution, engineers need flexibility particularly in ‘hard to treat’ buildings like warehouses and retail premises, which is where the lower targets will apply. The highest ratings will only be applied to buildings like offices and modern housing where design enhancements can be applied cost effectively.

A 15-18% energy saving across new and existing buildings would dramatically reduce demand on the energy grid and it is in existing buildings where the biggest and fastest changes can be made. The new Part L also includes energy efficiency targets for refurbishment work, but here too a flexible approach has been taken to ensure more buildings can be improved. 

For example, condensing heating appliances will be required to reach targets in many projects – and all new build, but in the retrofit commercial water heating sector there is some room for manoeuvre. Replacement of a non-condensing heater with a condensing equivalent can prove problematic dependent upon the installed flue system arrangement and access to drainage for condensate disposal. Design engineers have, therefore, been given some leeway in this area to keep costs realistic and non-condensing systems – still of sufficiently high energy performance – will be permitted to ensure low energy improvements are made.

Part L also encourages engineers to look at new and refurbished commercial buildings holistically and planning officials should look favourably on attempts to use the energy hierarchy, which starts with improvements to the building fabric such as replacement windows and insulation.

New fabric energy efficiency standards will be applied for new build dwellings while in existing commercial buildings attempts to improve the efficiency of installed systems by adding or upgrading controls will also be credited.

Existing regulations have tended to incentivise the use of individual technologies failing to give enough credit to the performance of complete building systems. By setting targets for fabric performance, Part L is starting to move the argument in favour of the complete building approach which favours the all-round expertise of building services design engineers.

It is similarly encouraging that the review of the Renewable Heat Incentive (RHI) has also taken the overall performance of complete building systems into account.

Traditional improvements
Adding renewables to a building should only be considered once fabric and existing technology energy efficiency improvements have been made and even then only where cost effective and technically appropriate. However, where traditional building methods are used, integrated onsite renewables will almost certainly have to be deployed to reach the higher 20% energy saving targets. If, on the other hand, a building is constructed using advanced sustainable techniques, such as PassivHaus, then the energy saving targets can be met using conventional high efficiency gas-fired technologies.

However, a weakness of Part L – and all other Building Regulations for that matter, has been the lack of robust enforcement on the part of local authorities. No matter how well intentioned and developed a regulation is, if it is not fully enforced then it will not be effective. The economic driver does give building developers and owners an incentive to reduce energy demand, but legal underpinning is equally important to ensure contractors are not tempted to offer ‘cheapest first’ solutions to secure contracts.

This is not a case of regulatory interference adding unfair burdens to industry, but basic common sense that can lead to dramatically lower operating costs for building occupants
and, even more importantly, help to keep its lights on.

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