For the ‘L’ of it

We now live in a ‘green’ world; producing sustainable products and services has become a global and cross industry requirement, with consumers putting more demands on providers to ensure that what they are supplying has minimal impact on the environment. We are all now more conscious of our carbon footprint and the impact we have on our planet. Consumers are voting with their feet and every item is now scrutinised for its carbon emissions, resulting in companies battling it out to become the ‘greenest’ around.

This has led to companies evaluating every component of the supply chain, including the buildings they operate in. With over 50 percent of the UK’s overall energy consumption and resulting carbon emissions being generated from buildings there is mounting pressure to reduce this significantly.

The Government is further strengthening the cause with the recent amendments to Approved Document L ( or Part L) and the introduction of Feed in Tariffs (FITs) for electricity production and incentives for renewable heating (due April 2011). These schemes will act as a ‘carrot and a stick’ for the industry; the stick being the Building Standards from Part L, and the carrot being a monetary value on generating heat and electricity and achieving zero carbon status for the project.

The question is what do funders, developers and building owners have to do to comply with the latest changes to Part L without incurring great cost? The soloution may not have to be  complicated. By making the small and simple amendments to a building’s design, owners can significantly improve energy performance ratings and meet Building Regulation requirements for little or no cost.

What is Part L?
In the UK, Building Regulations state that the ultimate objective is to reduce carbon dioxide emissions from domestic and non-domestic properties. This refers not only to new construction but to the refurbishment of existing buildings as well.

This energy efficiency aim has culminated in Approved Document L : Conservation of fuel and power, which is the regulation’s technical guidance that England and Wales must work towards; for Scotland it will be known as Technical Standard Section 6 (Energy).

Part L (England & Wales) is split in to four sections:
- L1A – Domestic, new build
- L1B – Domestic, refurbishment
- L2A – Non-domestic, new build
- L2B – Non-domestic, refurbishment

The primary focus for England and Wales is Part L2A, which stipulates an “aggregate 25 percent” improvement across all non-domestic buildings is required. This means that some areas, such as warehousing at 34 percent reduction, will have to take a heavier blow  than others such as hotels at just 16 percent reduction.

These improvements are not directed at the external thermal envelope, but at the energy efficiency of the building, taking account of all energy demands.  Scotland’s Section 6, sets out to reduce carbon emissions by 30 percent over 2007 figures, which is a 47 percent or 50 percent improvement over 2002 figures for heated and naturally or mechanically ventilated buildings.

The criteria for compliance with Part L legislation can be outlined as follows:
- Constructed to meet the Target Emission Rate
- Minimum performance standard; U-values (a heat transmission coefficient), system efficiencies and so on.
- Buildings not to be subjected to excessive overheating (therefore not liable to retro-fitted air conditioning)
- Building constructed and commissioned; actual performance is consistent with the Building Emission Rate (BER); air permeability testing and proper commissioning of building services
- Sufficient information has been provided to owner/occupier to enable operation in a reasonably efficient way.

How can companies meet Part L?
The demands of Part L can seem daunting and expensive, but if the right measures are taken compliance can be met at little or no cost.

The first place to start is the building envelope. Simply adding more insulation can achieve U-values better than those stated of the schemes ideal ‘Notional Building’ but will only achieve an energy saving of as little as  four percent. The cost to do this is potentially considerable, to accommodate the extra insulation and its weight, bigger purlins, rails, rafters and columns are needed. This in itself increases the embodied carbon of the building significantly due to the excess materials, plant and labour, thus negating any offset carbon. In fact, creating the notional building would incur considerable costs with very little gain, as the table above right  demonstrates.

There are other options to meet Part L that should be implemented which all come at no extra cost. CA Building Products has developed a Building Envelope Calculation tool (available on the CA website) that allows users to model their building envelope so they can quickly and easily see what effect their decisions will have.

As an example, on a 10,000 sqm building with a roof U-value of 0.25W/m2K, a rooflight U-value of 2.20 W/m2K and a wall U-value of 0.35 W/m2K, by simply improving air permeability to 2.5m3/hr/m2, the envelope performance is improved by almost 40 percent.  This can be improved further by ensuring thermally efficient details throughout the building.

Improvements, however, must also be mirrored in the provision of gas, electricity and water services. This is where renewable technologies known as Low and Zero Carbon technologies (LZCs) can come in to meet Part L requirements and improve the EPC rating of a building.

To ensure compliance with either Part L or Section 6, Energy Performance Certificates (EPCs) must be “affixed to the building”. The EPC is generated when the building is modelled using software such as the Simplified Building Energy Model which is in accordance with the National Calculation Methodology.

The information displayed on the EPC should include the carbon emissions and energy consumption for the building.

The higher the asset rating detailed on the EPC, the greater likelihood is the building will hold its value for longer and rental incomes will come under less pressure. It has been noted that rateable values and utility costs may rise as a result of poor asset ratings.

EPC ratings can be boosted by installing low or zero carbon (LZC) energy sources. Although Part L gives no guidance on specific LZC technologies, it does state that the designer should “consider making the building easily adaptable by facilitating the integration of additional LZC technologies”.

LZCs also reduce building running costs by up to 50 percent, and with the introduction of Government incentives, such as the FITs for electricity production and the upcoming Renewable Heat Incentive, they are becoming more cost effective and generate a profit for owners while seriously reducing the carbon dioxide emissions of the building.

Considering lifespan
Although not stipulated in Part L, the choice of building materials also has a major environmental  impact, through the embodied carbon in the products used and the effects of disposal at the end of the building’s life.

Owners should consider looking to products that can be recycled or reused (for example, on agricultural buildings), or sent back to the steel mill for recycling. This cannot be said for most forms of insulation, which need to be removed carefully from the building and transported to the nearest refrigeration recycling facility for safe disposal, where any potentially hazardous blowing agents can be captured.

Sustainability should not need to have major cost implications for building owners. Simple, small and low-or-no cost methods can help achieve compliance with Part L, while helping companies achieve their green promises as well.