Energist - Part L Compliance Experts - Blog

Over the coming weeks we’ll be examining the upcoming changes to SAP and SBEM in more detail, which will hopefully give you a bit of a head start when these tougher regulations kick in come October 1^st.

This week we are focusing on air testing – an area which we’ve already featured on this blog, so here’s recap:

For the last five years in England and Wales it has been advisable to have a test completed on a newly constructed building to measure how air tight it is. This is a feature of Part L and can make a large improvement to a SAP or SBEM calculation if a good air test is recorded.

The test itself has many names… ‘Air Leakage Tests’, ‘Air Permeability Assessments’, ‘Air Tightness Testing’… whatever you want to call it, it’s a measure of how much air is escaping or entering the building through the building fabric.

The air test itself isn’t changing with the new regulations, but there are some important areas you need to bear in mind.

Firstly, the amount of air tests which are required is being increased. Officially, around a quarter of all new dwellings need to be tested when built. Any development which is registered after the October 2010 date will need to comply with the new Part L, which means around half of new dwellings should be tested. It’s fair to say that, in reality, this figure will be lower and Building Control departments will retain their discretion on which plots and how many are tested.

Commercial developments remain the same. Any building with a floor area larger than 500 sqm must be tested – anything smaller can be tested in order to achieve a lower EPC rating, but this isn’t compulsory.

The other big change is the ‘confidence factor’. Currently, if a new dwelling isn’t tested, the SAP assessment is based on the value which a builder claims they can achieve. So if a builder has achieved an air test of 6 on a previous house, the SAP for the new house can also use the same figure.

From October, if any plots are not tested, the SAP calculation must be based on the average air test value on the site, plus two. So, if you have five new houses, have two tested, one result is 9.5 and the other result is 7.6, the three other plots will be assumed to have an air leakage figure = (9.5+7.6)/2 +2 = 10.55… the highest figure allowed is 10 which means your remaining plots will no longer comply with Part L.

A good rule to remember is that individual plots must achieve an air leakage rate better than 10, the site average must be better than 8.

And just to get some scope on this, Germany has a figure around 5, Scandinavian countries are around 3 and the Passivhaus standard would expect to reach around 0.5. Air tests are being phased into Scotland next year.

For more information on this, or to arrange for an air test, contact Energist UK for a free quote on 08458 386 387.

Over the coming weeks we’ll be examining the upcoming changes to SAP and SBEM in more detail, which will hopefully give you a bit of a head start when these tougher regulations kick in come October 1^st.

This week we are going to cast a watchful eye over emission factors. But first we need to know what these are, and why we’re talking about them…

In the depths of the SAP and SBEM calculation methods, the amount of power used on heating, hot water, lighting and general appliances is worked out in kilowatt hours. This figure needs to be converted into kilograms of CO2 in order to calculate the Design Emission Rate.

Every fuel type (electric, gas, oil etc) has an emission factor, which is a set value used to convert between energy use and emissions. For example, under SAP2005 the emission factor for mains gas is 0.194 – so, for every kilowatt of energy used by mains gas, you produce 194 grams of CO2.

This figure takes into account the amount of CO2 which is produced in the process of getting the fuel from the source (usually under the sea bed) to your home… so that includes refinement at power stations and transportation of the fuel (through tankers in the case of gas and liquid, or through pylons in the case of electricity).

Under current regs, grid electricity has the highest emission factor at 422 grams of CO2 per kilowatt hour – this explains why electric heating usually comes out with such a poor SAP rating.

Fuel types with low emission factors perform much better in SAP, such as Biomass, wood logs and woodchips (25 grams per kilowatt) – wood is treated as being nearly carbon neutral because it will only give off the same amount of CO2 ass the tree captured during its life.

The emission factors are being changed under the new regulations so they are based on more accurate, up-to-date figures.

The biggest shift is with grid electricity… it’s being made much worse jumping from 422 grams to 517 grams per kilowatt – if that doesn’t sound like much, think of the amount of kilowatt hours per year you get through by heating your home with electric panel heaters – your emission rates are going to jump by a quarter!

Oil is increasing by 12% and LPG by 5%. Wood based fuels are changing – some will be more favourable, some will be worse – but  these are going to have a minimal effect given the emission factors are already very low.

New fuels are being introduced to encourage builders to consider heating systems running on rapeseed oil, chip fat and geothermal energy (although we’re not sure how many people will be looking to heat their home via volcanic activity!)

This also works in reverse, if you produce your own electricity, the emission factor will be more favourable for you by around 7%.

For more information about emission factors, and how this will relate to the real world, let Energist UK look after your Part L needs, or book us for a training seminar in the regulation changes.

Contact 08458 386 387 for more information.

Over the coming weeks we’ll be examining the upcoming changes to SAP and SBEM in more detail, which give you a bit of a head start when these tougher regulations kick in come October 1^st.

One of the areas which the encroaching alterations to Part L is going to effect is the maximum U-Values allowed on new building projects – these changes only apply to SAP in England and Wales. The maximum figures for SBEM are not changing. Renovations and extensions also have lower U-Values coming into force.

So, let’s go back to basics… What is a U-Value?

A U-Value is a way of measuring how thermally efficient a particular part of a building is – these are calculated for all heat loss elements – namely the ground floor, roofs, external walls, doors, windows and rooflights. Walls and floors adjoining unheated rooms, such as a garage or conservatory, are also included.

The U-Value is shown in W/m2K – (Watts over metres squared Kelvin) – and the lower the better (A U-Value of zero would mean that no heat loss was transferring through the element).

Under current regulations the maximum U-Value allowed for a floor is an overall average of 0.25 – on a typical house you’d expect around 100mm of mineral wool to reach this figure. Under the new regulations, this is not changing in either residential or commercial builds.

The maximum U-Value allowed for a roof is an average of 0.25 – around 200mm of mineral wool will reach a figure round that mark, although it’s usual practice to exceed this U-Value – it makes a good impact on SAP to install 300mm for not too much more cost. Come October, the average U-Value for a roof is being lowered to 0.2.

Wall U-Values are also being lowered – from 0.35 to 0.3. A standard cavity wall with full fill mineral wool should be hitting the 0.3 mark.

Currently, the average U-Value of all external doors, windows and rooflights must be no greater than 2.2 – this is being reduced to 2.0. If you’re using a good specification double glazed unit, you should find yourself around the 1.7 mark.

For SAP, There are also two NEW areas of the build which are being introduced into the calculation for the first time: Swimming pool basins must be constructed to achieve a U-Value no higher than 0.25, but the change which will effect more builders is concerning party walls.

Until now, it’s been assumed that any heat leaking through a party wall will heat the neighbouring house and vice versa, therefore having no overall effect. It’s been proven in recent years that heat escapes into party walls, and travels up the cavity into the roofspace. It is therefore advisable that, come October, all houses are constructed with an insulated party wall, sealed at the top.

A final point to note is that these changes are to be maximum values allowed – there are lots of other things going on in the new SAP calculation which will make the regulation tougher to pass, so we’ll be recommending to our clients that they aim to exceed these limiting values by as big a margin as possible.

For more information on how the regulation changes are going to effect the way you do business, contact Energist UK on 08458 386 387.

On this blog before we have covered the news that Part L is changing, that SAP and SBEM are changing with it, and that the energy efficiency of new buildings is going to be tightened up come October.

This is happening across the UK – but how much of a difference depends on where you live and what you’re building.

Let’s start with the residential market in England and Wales. Come October there’s going to be tighter U-Values limits, new U-Values which haven’t been needed before, tighter air leakage demands, more low energy lighting, better glazing specification, fewer exemptions, more attention paid to thermal bridges and thermal mass and, the big change: a 25% reduction on the Target Emission Rate.

Compare that to what’s going to be happening in the commercial sector in Part L2 for England and Wales. For SBEM calculations, most of the regulations are staying the same as before. U-Value requirements aren’t changing, heating efficiencies are staying the same… the only difference is the 25% reduction in the Target Emission Rate… but even that’s not going to be simple.

The 25% cut is going to be an average, based on the type of building being assessed – so some commercial developers will only need to reduce their emissions by 20%, others by 30%. It’s been known for some time that particular commercial buildings fair better in the SBEM calculation than others, this system is an attempt to iron out this problem, while reducing the limits on emissions at the same time.

Confused yet… let’s head over the border.

For residential developments under Section 6 in Scotland, the Target Emission Rate is going to be reduced ‘by approximately 30%’ compared to where it is now. ‘Approximately’ is how the Scottish Building Standards Agency has phrased it – they’re using the average approach (more commonly known as the aggregate TER) which is being used on commercial buildings in England and Wales. On top of this, the SBSA is also going to be offering guidance for improving the energy efficiency of existing buildings, encouraging a greater use of low carbon systems in new homes, lowering the maximum U-Values and from 2011 air leakage testing will be brought in for the first time.

Finally for now, Scottish commercial developments. Maximum U-Values are being lowered, and are going to be different to that used on the domestic side. The Target Emission Rate is going to see a flat 30% reduction (not based on an average system) and air leakage tests will be introduced in 2011. For commercial shells, the air test must meet seven with a secondary air test to be completed once the fit out stage has been completed.

Somehow, the technical team at Energist UK understand all the changes that are being introduced into Part L and Section 6 over the coming twelve months, and will be able to help you with any queries you have. Call us on 08458 386 387.

Firstly, I feel the need to offer huge ‘Congratulations’ to the brave team from Energist who completed a charity abseil last weekend.

MD Sarah Fenwick, sustainability expert Rosemary Bailey, Stuart Clark from the CSH team and Laura Pitcher from our Customer Service department managed to raise more than £1,100 for the Winston’s Wish charity – an organisation which helps bereaved children.

The abseil was down the face of the Eagle Tower in Cheltenham – the tallest tower block in the city stretching up fifteen storeys.

It’s not too late to donate! There’s always somebody in the Energist team looking to raise money for one charity or another. Keep in touch with us and we’ll let you know our upcoming fundraising events.

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Elsewhere in Cheltenham this week, Energist teamed up with solicitors, Rickerby’s, to offer a free training seminar covering BREEAM Communities and an update on the Government’s Carbon Reduction Commitment.

The morning was attended by a mix of fifty architects, surveyors, lawyers and people from across the construction industry, keen to find out more about how the new BREEAM scheme will effect the planning and development of future sites.

Attendees were also given an update on the CRC Energy Efficiency Scheme (previously known as the Carbon Reduction Commitment) which was launched in April, and is a plan to raise awareness in large organisations about energy saving measures and to encourage changes in behaviour and infrastructure.

In July, Energist will be hosting a training morning dedicated to the changes in Part L regulations, the effect this will have on SAP and SBEM calculations.

For more information about this and other training sessions which are available, contact our Customer Support team on 08458 386 387.

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The final story of the week looks at the Government announcement of a series of cuts which has instantly hit a number of grants for installation renewable technologies in the home.

The Department of Energy And Climate Change has had its budget cut as part of the coalition Government’s saving plans. It means that, with immediate effect, there are no grants available for installing heat pumps or solar panels.

Grants for using photovoltaic panels or wind turbines were scrapped under Labour, with a Feed-In Tariff introduced to replace it.

It’s thought this announcement will put a dent in the amount of renovation projects using renewable technologies, but it isn’t expected to have such an impact on new build developments, which are being forced to use more energy efficient means of fuel by building regulations.