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’re going to look at heating, cooling and ventilation systems, and how your SAP calculation can be dramatically affected by the heating system you choose for your dwelling.

We’ve already covered fuel emission factors in a previous posting (which explains why different fuel types have such an impact on emission rates) so feel free to look back and catch up with us on that section!

As assessors, when we are completing a SAP (or SBEM for that matter), we have a list of dropdown boxes and options which we use to most accurately reflect the heating system to be used in a building.

This is fine for a standard house with a standard boiler, but when you get into the realms of a twelve bedroom mansion with a heat pump, separate boiler and immersion back-up, the SAP methodology doesn’t take account of the full picture.

SAP2005 can only deal with one main heating system per plot, one type of water heating and one type of secondary heating (which is either a fireplace, log burner or decorative fireplace. We can only enter one type of ventilation system (either standard extraction fans or a mechanical ventilation system) and there is no scope for entering comfort cooling systems. Also, currently heat pump efficiencies cannot be entered – SAP will always assume default figures which are usually higher than the actual product.

When the new Part L kicks in, SAP is being enhanced to give us (the assessors) a bigger array of options for the calculation… which will help to give more accurate figures overall.

The new SAP will allow two separate heating systems to be entered for one dwelling… if a heat pump is involved, we will be able to enter the actual efficiency (the co-efficient of performance) instead of having to make do with the default figure. Also, there will be the ability to enter two types of ventilation system – this will benefit large buildings which have heat recovery in some areas only.

Another change will be the introduction of cooling systems into SAP. If you are planning on installing a cooling system, your energy use will go up (which makes sense… the current SAP ignores them completely), but there’s a bit of a twist….

The assumed use of the cooling system will be geographically specific – in other words, SAP will predict the cooler will need more power in Cornwall compared to the Isle of Skye because of the change in climate. So the further south you go, the worse emission rates you’ll get. Interestingly the same does NOT apply to heating systems, although there are rumours this will be included in the next revision of SAP methodology.

If you’d like any more information on the changes to the Part L Building Regulations please give Energist on 08458 386 387 to see how we can help.

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.

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.

It’s the document you’ve all been waiting for!

The 2010 Part L legislation has now been released. The books, which will not come into force until October, cover the ‘conservation of fuel and power’ in England and Wales building regulations.

The Government has released this a few months early so the building industry can get itself prepared for the oncoming changes, which will affect SAP and SBEM calculations, Energy Performance Certificates, Air Leakage Testing and the construction of new buildings and extensions alike.

Previously on this blog, we’ve already talked about some of the changes to the SAP calculator, this is a different document which will again come into force in October. The SAP methodology and Part L go hand-in-hand.

The biggest change we will notice, as expected, is that the way the Target Emission Rate is calculated is being changed… there are going to be two different methods. For SAP calculations, the TER will be calculated in the same way, but with a 25% reduction on the current regulations. This will mean new houses will need to be built more efficiently to comply.

For commercial buildings, the TER is going to be worked out in a different way to more accurately reflect the building it is being measured against. This should help to eradicate the ‘issue’ currently with SBEM that allows buildings to fly-through when air conditioning is used… A 25% reduction is also being added.

Maximum U-Values are also changing, but only on SAP. From October, all external walls must be 0.30 or lower, all roofs must be 0.2 or lower and glazing must be 2.0 or lower. In addition to this, party walls are going to be introduced into the calculations for the first time. Party walls must achieve a U-Value of 0.2 or lower.

This doesn’t apply to commercial buildings, which will use the same U-Value limits as before. Bearing in mind the lower emission target, we’re expecting developers will need to build elements far lower than these maximum values in order to comply. Maximum U-Values are also being lowered for domestic extensions.

The frequency of Air Leakage Tests is being increased, and a ‘confidence factor’ is being introduced – this is quite a positive term, when you realize it’s a way of penalising plots which are not tested.

For example, if you have ten identical plots and four are tested. The other six will need to use the average result plus two. So, remembering the air leakage limit is ten, if your average air test figure is higher than eight, any plots which are not tested will record a value higher than ten, which will not comply.

The procedure of Part L is also being tightened up – when a building is completed, you’ll have just FIVE DAYS to present the As Built reports and Energy Performance Certificate to Building Control. Also, design SAP and SBEM reports will need to be submitted to Building Control before the development is given the go-ahead by the authority.

I don’t want to re-write all hundred-or-so pages of Part L, but there are plenty of other changes being brought into effect regarding Part G, lighting and thermal bridging to name but a few.

If you would like more information on how the changes to Part L are going to effect your business, and how we can help, contact Energist UK on 08458 386 387.

This week, BRE has published the SAP2009 document. This will replace the current SAP Calculation for any dwellings which go through planning as of October of this year. It is the biggest change to Part L since 2005 and is the next step in the Government’s drive to ensure all new build homes will be carbon neutral by 2016.

The first thing to say on this, is these changes will not effect any projects you are currently working on – providing you go through planning approval in the next six months.

Here are some of the big changes you should be aware of…

PARTY WALLS: Up until now, SAP has ignored the walls between dwellings. This is going to change as it’s been discovered that more heat escapes through these walls than previously thought. For example, an uninsulated party wall without edge sealing will be assumed to have a U-Value of 0.5. Bearing in mind this will be combined with the U-Values for the external walls, and that combined value will still need to be better than 0.35, it makes sense to insulate between houses.

FUEL FACTORS: This is a way of judging how environmentally friendly each type of fuel is and includes creation, transportation and end use efficiencies. The emission factor for electricity is going to be increased by 40% making it much more difficult to pass a SAP using panel heaters. Meanwhile fuels such as biomass are seeing a reduction in emission factors, so there will be more of an incentive to use this kind of technology.

CONSTRUCTION: This is being brought in from Northern Ireland assessments. A masonry built house has a greater mass than a timber frame, so it traps heat in the walls better, slowly releasing the heat back into the building. SAP 2009 will be taking this into consideration.

TARGET EMISSION RATE: This is being lowered to bring a standard SAP assessment down to the level that a Code for Sustainable Home Level 3 house is today. This will mean an emission saving of 25% will be needed on all new homes when compared to the current SAP assessment.

HEATING: Details about heating, cooling, ventilation and heat recovery systems are being updated to allow more information to be included in the SAP assessment.

WATER USE: A cap of 125 litres of water per person per day is being imposed on new builds under this new regulation, although it’s not clear how this limit is going to be policed.

As you can see Energist’s assessment team is already getting clued up about these changes, so we will be completely up to speed by the time this document becomes a legal requirement in October.

Call us for more information on 08458 386 387.