Technical information

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Meeting Part L
The quick start guide!
Part L of the Building Regulations deals with the Conservation of Fuel and Power and is the
regulation that affects electric heating systems in both new build and existing dwellings.
The Government has now confirmed that the implementation date for
revisions of Part L will be 1st October 2010. However, at the time of
going to press detailed information on how the new regulations will affect
electric heating is still unclear, but there will be transitional provisions
that allow building work to be completed after this date using the current
2006 edition of Part L.
These transitional provisions require a Building Regulation Application to
be lodged before 1st October 2010 and work to start on site before 1st
October 2011. There is no requirement to gain an unconditional Plans
Approval within this 12 months period and for this reason the transitional
provisions are not onerous to utilise.
Because of the lack of clarity on the 2010 changes and the fact that there
is a transitional period, we have continued to provide information on how
to comply with Part L 2006 as we believe this is the regulation that most
organisations will be building to during the life of this brochure.
What changed in 2006?
All the old methods of compliance were abolished and replaced with a
Target Carbon Emission Rate (TER).
Whatever fuel type you choose for the heating and hot water of your new
building – gas, oil, LPG or electric – you have to show that the overall
carbon emission rate is less than the target for that building type.
There are also minimum standards for U-values and air-tightness, which
must be tested on completion of the building. However, even meeting all
the minimum standards will not guarantee a pass.
The biggest change is that under the new rules the whole building is
taken into consideration. Every factor that can influence carbon emissions
is relevant and it’s the whole building that must pass. So just building
to minimum standards may not guarantee a pass because the whole
building may still exceed the target carbon emission rate.
What’s my target?
The target is set in terms of Kilograms of carbon dioxide for every square
metre of the building, over the course of a year (KgCO
2
/m
2
/yr).
A range of sample buildings is used to set the target, which is then
adjusted for the size and shape of the actual design and the heating and
hot water plan.
The complex calculation of both the target and the actual score of your
new building can be performed within special SAP 2005 approved
software. (The government’s adopted Standard Assessment Procedure).
An accredited SAP assessor is required to complete this.
Meeting Part L – The quick start guide!
Meeting Part L – The quick start guide!
The targets created under Part L 2006 demand a 20% reduction in carbon
emissions compared with the previous rules. This new tougher target
was set to improve the country’s energy efficiency and dependence on
imported fuel and to reduce the devastating effects of climate change.
The tougher target applies to all relevant buildings, all products and
all fuel types. It’s the whole building that must comply, not any given
product or building service.
Block Assessment
Part L 2006 has important rules for setting and achieving the targets in
flats and apartments. So called ‘Block Assessment’ allows for all the
flats or apartments in a building to be assessed in one go.
Each flat or apartment can be dealt with as the developer or specifier
feels appropriate for meeting the overall TER, across the different floors
and sides of the building. Any given flat or apartment does not have to
meet an individual TER as long as the whole building does.
This allows the developer or specifier flexibility in how to achieve
the target. For example, solar thermal to selected flats or mechanical
ventilation with heat recovery may be installed which would create carbon
savings that can be shared out across the whole building. It also reduces
running costs and becomes a major selling feature. For more advice on
saving energy see the guide at the back of this brochure.
Can you comply using electric heating and hot water?
Yes.
The only test for compliance is that the building does not exceed the
target carbon emission rate. We continue to supply electric heating and
hot water solutions into fully compliant buildings. Electric heating has
also been shown to have lower lifetime costs of ownership than gas, is
easier and quicker to install, is maintenance free, offers great design
flexibility and has lower initial capital costs.
Electric heating is the fuel of the future. Low carbon electricity from UK
sources produces low carbon heating only with electric products.
How do I reduce the carbon emission rate of a building?
There are a number approaches that are proving most effective at
reducing the carbon emission rate of a building. We recommend you
consider the following options. In isolation or in combination, all of these
options have been used in conjunction with modern electric heating.
6 Improve the lighting plan:
In some buildings the carbon impact of the lighting can be significant
and expert advice can assist in demonstrating compliance with Part
L. Modular lighting strategies should be considered. The traditional
rules of thumb based on the number of rooms should give way to
a recommended number of lighting points by square metre of floor
area. It is good practice to install low energy fittings as standard
indoors, with consideration given to highly effective control.
Externally the regulations require a maximum 150W with automatic
switch-off via PIR, photocell and timers.
7 Controllability reduces emissions:
It has been shown that easy to use, highly responsive heating
systems actually reduce carbon emissions. When heating responds
quickly it tends, in practice, to be used more effectively. Where
controls are simple to use, people make better use of them. Modern
electric heating is highly controllable and responsive. This is
recognised within SAP. We offer leading edge electric heating with
our Eco-Response technology. Integrated and sensitive thermostats
within Creda electric heating products allow precise control room
by room, ensuring solar gain is taken into account in maintaining a
desired temperature and reducing carbon emissions.
8 Background heat:
By ensuring there is a low level background heat throughout the
common walkways, like stairwells and landings in apartment
blocks, adjoining walls are only considered semi-exposed for
calculation purposes, reducing heat losses and improving the carbon
emission rate. We offer modern electric heating solutions designed
for this purpose.
9 Size the cylinder:
The regulations now assume a 170l water cylinder. By ensuring the
cylinder is not oversized for its application, heat losses are reduced.
If the cylinder size is reduced below 170l then the carbon emission
rate is improved.
Eco-Response
1 Improve the air-tightness:
It is now mandatory to test the air-tightness of a building on its
completion. There are minimum levels required under the new
regulations but improving on these has been shown to be one of the
best ways to reduce the carbon emission rate and therefore comply
with Part L. Electric heating is helpful in this regard as it results in
less holes and gaps in the building fabric than gas heating systems.
The regulations require a minimum air-tightness of 10 cubic metres
per hour per square metre of floor area at 50 Pascals of pressure.
(10m
3
/h/m
2
@ 50Pa). Many developments can now achieve 7 or 5
and some even 3m
3
/h/m
2
@ 50Pa.
2 Install mechanical ventilation with heat recovery:
Used in conjunction with improved air-tightness, so called MVHR
recovers otherwise wasted heat and is a great advantage to the
ventilation strategy. There are specific provisions within SAP
(Appendix Q) which show how using MVHR can reduce the carbon
emissions rate and help compliance with Part L.
3 Improve the building fabric:
There are minimum U-values for all elements of the building fabric.
U-values are a measure of how much heat energy can escape through
a given element of a building. However, simply meeting these
alone does not guarantee compliance. By exceeding the minimum
requirement significant improvements can be made on the carbon
emission rate. It is possible to show compliance with Part L just
by improving building fabric U-values. However, a combination of
improved air-tightness, MVHR and modest improvements in building
fabric U-values has proved most cost effective in many building
developments. Consider reducing U-values for roofs to 0.14, walls
to 0.3, floors to 0.2 and glazing to 1.8 but, generally speaking, the
lower the better.
4 Consider glazing as a percentage of the building floor area:
The regulations assume that glazing coverage is equivalent to 25%
of the floor area, which is more than most developments. Where this
can be sensibly reduced it will improve the carbon emission rate
of the building. If the specification of glazing is also improved the
impact is increased. Consider gas filled or triple glazing.
5 Go renewable:
The installation of solar thermal hot water systems, heat-pumps or
micro wind-turbines can have a number of major benefits. Often
the installation of some of these products can turn an otherwise
non-compliant building into a fully compliant one. However, many
developers now also see this as the preferred route to meeting other
planning requirements or aspirational targets for the use of micro-
generation technologies. They can significantly reduce running costs
and can be a great selling point. Please contact your Creda regional
manager for more information.
For more information on the new regulations go to www.communities.gov.uk/planningandbuilding