The next update of the Building Regulations 2010 for England and Wales is upon us, and this time it is Part L, and the conservation of fuel and power. This handy guide will attempt to break it down to what you need to know, why you need to know it, how to go about finding out more, and why you’re doing all this in the first place.

1. AN INTRO TO THE CHANGES TO PART L OF THE BUILDING REGULATIONS
A GUIDE TO THE CHANGES IN
PART L 2013
By SpecifiedBy.com
© SpecifiedBy 2014
SpecifiedBy.com
Empowering Building Projects with Better Information

2. Contents
1. Introduction
2. What’s Happening & Why?
3. What Does All This Mean?
4. Considerations for Architects & Designers
5. Compliance Alert!
6. Part L Resources
7. Building Regs Online
© SpecifiedBy 2014
Written by Blair Martin

3. The next update of the Building Regulations 2010 for England and Wales is
upon us, and this time it is Part L, and the conservation of fuel and power.
This is an area of keen focus as far as carbon emissions are concerned, as it
can play a major role in achieving the UK’s self-imposed targets on carbon
reduction.
The update follows a consultation with industry during 2012, and the new
contents were announced in July 2013.
Hopefully that means you’ve had plenty of time to get to grips with what
exactly is changing – if you’re an architect who is already targeting Code for
Sustainable Homes level 4 or BREEAM Excellent buildings then you’ll
already be achieving these targets.
But just in case you haven’t or if this is in fact the first you’ve heard of it,
then this handy guide will attempt to break it down to what you need to
know, why you need to know it, how to go about finding out more, and
why you’re doing all this in the first place.
Darren Lester
Founder, SpecifiedBy
Introduction

4. WHAT’S HAPPENING
& WHY?
@SpecifiedBy
Part L Changes

5. The new part L regulations will attempt to improve on the standards
required to achieve zero carbon homes by 2016 and commercial buildings
by 2019. In case you’re not aware, the UK is the first country to set legally
binding carbon budgets, and these figures are merely stepping stones to
achieving longer term goals.
If you already know about carbon budgets, you can probably skip this part.
If you don’t, feel free to read on.
Carbon Budgets
The main target right now is to achieve an 80% reduction of 1990 levels of
CO2 emissions by the year 2050.
The carbon budget for the UK places a restriction on the total amount of
greenhouse gasses that the country can emit over a five year period – if
emissions rise in one sector, corresponding falls in another sector need to
be achieved.
The building sector accounts for a majority of greenhouse gas emissions in
the UK, and residential properties alone currently account for around 15%,
while energy supply accounts for around 42%.
Something to ponder is that the building industry is potentially influential
of (not directly responsible for) up to 47% of the total UK emissions. That’s
nearly half of the country’s entire greenhouse gas output, so it is perhaps
understandable that the Building Regulations and specifically, the
conservation of fuel and power are under the spotlight again.
What’s Happening & Why?
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6. 6th April 2014
The new regulations come in to force on 6th April 2014, and aim to
reduce greenhouse gas emissions throughout the whole build process,
from design to completion.
Domestic
Residential dwellings require a 6% reduction on 2010 levels, which were
themselves a 25% reduction on 2006 levels. This is slightly lower than the
proposed 8%, but the Government wanted to achieve a balance between
the lower emissions and keeping costs at a commercially realistic level.
Non-Domestic
Meanwhile commercial properties require a 9% reduction. Wales are going
for the 8% reduction on new builds, which incidentally is the first time
they’ve gone it alone with their own version.
The Government predict that these changes will equate to projected
savings of £16m per annum to businesses, and save an additional 6.4
million tonnes of CO2 per annum.
If Marvel’s Ultimate Alliance were to sit around a table and thrash out
building regulation amendments, then they would probably be like this.
What’s Happening & Why?
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7. WHAT DOES ALL
THIS MEAN?
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Part L Changes

8. What this actually means for you can be boiled down to just a few main
points.
There are now new versions of Approved Documents L1A and L2A.
Approved documents L1B and L2B have been amended and updated as
well, though this is only some minor wording changes and clarifications,
and there are new versions of both domestic and non-domestic Building
Services Compliance Guides.
The main new additional points of the updated L1A Conservation of fuel
and power (new dwellings) are:
• A new regulation, 26A, has been introduced that requires new dwellings
to achieve or better a FEE target in addition to the CO2 target. This
equates to around a 15% reduction on FEES levels. New builds will
require a DER and a DFEE rate that is no worse than the TER and TFEE as
calculated. These targets and calculations must be provided to the local
authorities no later than the day before work commences.
• The FEES is affected mainly by building fabric u-values and areas, which
means that this target will need to be considered from the early
building fabric design stage. The main culprits here are roofs, floors,
walls, windows and doors, thermal bridging PSI values, air tightness,
heat gains from solar energy and lighting and appliances. What this
translates to is a slight reduction in u-values and as a rough guide new
builds will typically need to achieve the following levels:
What Does All This Mean?
@SpecifiedBy

9. • The notional dwelling used to determine CO2 and FEE targets must be
the same size and shape as the actual dwelling, constructed to a
concurrent specification.
• If the actual dwelling is constructed entirely to the notional dwelling
specs it will meet the targets and limiting values for individual fabric
elements and building services. However, developers are free to vary
the specs provided the same overall CO2 emissions and FEE is achieved
or bettered.
• Amendments made in December 2012 are now consolidated. These
require the feasibility of high-efficiency alternative systems are taken
into account before construction commences.
• Guidance for insulation of circular pipes within communal spaces is
given greater prominence.
@SpecifiedBy
What Does All This Mean?
Walls 0.18 W/m2K
Floors 0.13 W/m2K
Roofs 0.13 W/m2K
Party Walls 0 W/m2K
Air Tightness 5m3/m2/hr at 50 Pa
Windows & Doors 1.4 W/m2K (1.0W/m2K for solid & 1.2 W/m2K for
opaque
Thermal Bridging Lengths x psi values are detailed in SAP 2012

10. The main points of L2A Conservation of fuel and power (new buildings
other than dwellings) are:
• The notional building used to determine CO2 targets is to be the same
size and shape as the actual building, constructed to a concurrent
specification.
• A wider set of notional buildings is now defined for top-lit, side-lit
(heated only) and side-lit (heated and cooled) buildings, and the
notional air permeability has been further subdivided by size.
• A summary of notional buildings has been published separately with full
details in the NCM modelling guide.
• Amendments made in December 2012 are now consolidated. These
require the feasibility of high-efficiency alternative systems are taken
into account before construction commences.
@SpecifiedBy
What Does All This Mean?

11. SAP 2012
Another change you need to be aware of is the introduction of SAP 2012.
The Department of Energy and Climate Change have updated the Standard
Assessment Procedure (again, following a consultation) and the new
version will be required for compliance from the same date everything else
kicks in (April 6th in England and 31st July in Wales).
SAP 2012 version 9.92 is available to download for free, and covers the
following key technical changes:
• Energy related CH4 and N2o emissions will be included as CO2
equivalents.
• Related transport emissions will be included in CO2 emission factors.
• Energy supply chain emissions to be included no matter where they
occur (both inside and outside the UK).
• Emission factor to be a system average for both imports and exports of
grid supply fuels (instead of a system average value for consumption
and a marginal value for exports to the grid)
• Wind speed data to be an influencing factor on the basis of dwelling
location
• Proposals for solar radiation calculations to be based on orientation and
pitch have been agreed
• RDSAP for existing dwellings will also include the changes.
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What Does All This Mean?

12. This updated version also followed a consultation. There are a few other
changes that may affect you but these are the main changes to give you an
idea of what has been included.
The full list of what’s been added can be found in the consultation, which is
linked at the end of this guide.
@SpecifiedBy
What Does All This Mean?

13. CONSIDERATIONS FOR
ARCHITECTS & DESIGNERS
@SpecifiedBy
Part L Changes

14. FEES
Perhaps the most significant change to consider is that of the FEES, which
aims to minimise heat loss from the building envelope.
The target will vary depending on the type of dwelling, and will therefore
be more challenging to achieve for types such as end terraces, and will
require a more detailed consideration of low u-value materials for windows
and doors, better insulation for walls and roofs, reduced cold bridging and
a more air-tight structure.
On a positive note, the changes should promote a fabric-first design
approach as opposed to using renewables as a costly solution to being
over target on carbon emissions.
These design-level changes will most likely bring about greater
coordination between the architect and structural and business services
engineers.
Therefore risks to project viability and planning success will be reduced as
the whole team discusses orientation, fabric and energy strategies at the
concept stage in order to meet the required targets; so get the biccies in!
@SpecifiedBy
Considerations for Architects & Designers

15. Design Stage Considerations
A lot of the other additions will need to be considered at the design phase.
For example the material you decide to use will be after consideration of
achieving the desired u-values and air tightness.
Thermal bridging will also be an early consideration of the frame design.
Unfortunately these things are likely to make the process more expensive,
both in time taken and materials used, so you’ll need to make sure you
quote the right price for your time.
Also, when carrying out the energy rating, the updated changes and new
considerations of SAP 2012 need to be factored in to achieve an accurate
and compliant result.
@SpecifiedBy
Considerations for Architects & Designers

16. COMPLIANCE ALERT!
There is a risk of being out of compliance with the
new regulations. Here’s how to avoid it.
@SpecifiedBy
Part L Changes

17. If you registered the build on or before April 6th this year and
commence within a year, then the old regulations still apply.
Thereafter any buildings that are registered will need to comply with the
new regulations. It has been suggested that it is critical that Part L 2016 is
drafted now, so the sooner you get to grip with these changes, the better
equipped you’ll be to tackle the next round of changes.
You’ll also be playing a role in Britain achieving emission targets and
therefore helping to save the world, one building at a time, which might
give you a warm fuzzy feeling inside. Or not, but you still have to comply.
So this is how to comply:
In addition to the five main steps of compliance listed in the most recent
Building Regulations, the updated Approved Document L1A contains a
separate, specific list for Part L 2013. These are:
• The DER from the dwelling must not exceed the TER. Also, the DFEE
must not be greater than the TFEE. This is a regulation and hence
mandatory, but on the plus side the calculations involved here can also
provide information for the energy performance certificate that you’ll
also need to provide.
@SpecifiedBy
Compliance Alert!

18. • The performance of the individual fabric elements and the fixed
building services of the building should achieve reasonable standards of
energy efficiency. This is to limit inappropriate trade-offs, for example
poor heat transfer standards being offset by an uncertain sustainable
energy source.
• The building should not overheat in summer, and therefore requires
passive control measures to limit the effect of heat gains, even if the
building is air conditioned.
• The performance of the dwelling should be consistent with the DER and
DFEE rates.
• Necessary provisions for enabling energy-efficient operation of the
building should be in place.
Full guidance, relevant procedures and all the calculations you’ll need in
achieving all of this are detailed in the Approved Documents.
In addition to these, you’ll need to remember the dates and what they
mean – as a reminder, any building registered before 6th April 2014 and
commenced within a year of that date or any building currently under
construction can carry on as before.
Any other registrations will need to follow the new regulations.
@SpecifiedBy
Compliance Alert!

19. Part L Resources
To finish, here’s a collection of websites and
articles worth visiting to learn more about the
changes to Part L.
@SpecifiedBy
Part L Changes

20. This guide is intended as exactly that – a guide. It is not an exhaustive list of
the changes, and serves mainly as a starting point to what you should
probably know.
For full guidance on compliance, dates, calculations, where to download
SAP 2012, and anything else that may be necessary, check out the following
sites:
The new Approved Documents L1A, L1B, L2A, L2B, and both the Domestic
and Non-Domestic Building Services Compliance Guides
Online Building Regs from SpecifiedBy
SAP 2012
Part L consultation
SAP consultation
Carbon Budgets Policy
Government CO2 Emissions Report
Part L Resources
© SpecifiedBy 2014
Written by Blair Martin

21. Free Online Building Regs
“Keeping building designs & projects inline with the correct
legislation is a time consuming & challenging task.”
It’s not helped by the fact that the documents required to do this are only
freely accessible as PDFs.
The PDF is limiting, can be hugely frustrating and is most definitely not
suited to reading highly technical documents; whether that be on a
desktop, tablet or mobile.
In short, it's a closed format that makes your job just that little bit more
difficult.
So wouldn’t it be great to be able to quickly and freely access these
documents in a user friendly format, that let's you use the information how
you want to and on any device?
This is why we’re converting all of the Building Regulation Documents
into HTML format, or webpages to you and me, and making them free
to access.
If you would like to see this in action and be one of the first to access this
useful tool visit the link below.
Access Online Building Regs