Focusing on refurb
(written for Modern Building
If the UK is to meet its emissions targets, more attention needs to
be paid to refurbishment. Ant Wilson of AECOM takes a look at the key
When it comes to helping the UK meet its carbon emissions targets it’s
clear that building services engineers have a very important role to
play. Increasingly, it’s also becoming clear that this role will have
the greatest impact through refurbishment of existing building stock –
and that there needs to be tighter integration between services and
This is in contrast to early energy-saving initiatives that put a strong
focus on the performance of new buildings. The fact of the matter is
that most new build is adding to the total number of buildings, rather
than replacing badly performing existing buildings. In the domestic
sector, for instance, there are plans to build seven million new
dwellings by 2050. And even if the goal of carbon-neutrality for all new
homes by 2016 is achieved, this is only preventing the situation getting
The same is true for the commercial sector, where many of the buildings
in use today are still going to be in use 30 years or more from now. All
of which explains why our emphasis needs to switch to refurbishment – if
it hasn’t already.
To that end, there are several drivers that building operators are
currently responding to. Energy Performance Certificates and Display
Energy Certificates are certainly having an effect, as is the need to be
‘seen to be green’. The major supermarkets, for instance, are all vying
to have the best environmental performance because this may influence
their customers. At the other end of the spectrum, universities are
finding that student choices are also influenced by green issues.
Similarly, developers and landlords are finding that efficient building
performance can increase their chances of letting a space, so that it
becomes financially attractive to invest in improvements, rather than
have space lying empty while still attracting business rate charges.
From a legislative point of view, the consequential improvements
embedded in the current Building Regulations also have an effect. There
has also been a suggestion that future Building Regulations will
strengthen this requirement, though it is as yet unclear whether this
It’s also worth mentioning that some people try to avoid making
improvements on the grounds that their building is listed or has
heritage status. The reality is that there are many improvements that
can be made to insulation levels and central plant that won’t
‘unacceptably alter the character or the appearance’ of the building.
So, with this focus firmly in mind, is there an ideal approach to
refurbishment? I would say that we need to look at every aspect and
every stage – the fabric, the central plant and distribution services,
the controls, the commissioning and ongoing operation and maintenance
The place to start is with behavioural change to achieve the quickest
and most cost-effective wins – followed closely by attention to the
fabric. And while the fabric may often fall outside the remit of the
building services engineer, improvements to the thermal performance of
the fabric will influence the possibilities for the services. For
instance, reducing solar heat gains may open the door for chilled beams
rather than fan coils. Or better insulation may facilitate use of lower
flow and return hot water temperatures to make better use of condensing
boilers and heat pumps.
It’s also the case that many of the ‘quick wins’ that building operators
are looking for are delivered through improvements to existing services.
Upgrading lighting to more efficient sources with better control offers
relatively fast paybacks, as does the installation of variable speed
control on pumps and fans. Equally, major savings can be achieved by
reducing heat gains and losses from distribution systems by better
insulation of pipes and ductwork.
Where central plant is replaced it’s important to follow the Building
Services Compliance guides for each type of kit. Appropriate controls
are also important to ensure the plant performs as well in reality as it
does under test conditions. Testing, adjusting and re-testing should
therefore be an essential part of the commissioning process.
There may also be opportunities to introduce renewable energy sources to
a refurbishment process and the current proposed feed-in tariffs are
actually making this more viable for refurbishment projects than for new
build. For example if a photovoltaic installation of less than 4kW
capacity saves 10p/kWh, the payback may be 60 years. However, if an
additional 36.5p/kWh is provided as a grant, the whole return on
investment calculation changes radically.
Of course, the onus doesn’t lie entirely with the construction
disciplines as the building operator also has a role to play in ensuring
efficient maintenance – from cleaning filters and luminaires to regular
servicing of plant – to maintain design performance. Here again, though,
the building services engineer can help by providing detailed, accurate
and easy to follow O&M information.
When all of these factors are taken into account, it’s perfectly
possible to make major inroads into the carbon emissions resulting from
the built environment. And the fact that it’s all common sense means
there’s no excuse for failing to deliver those benefits.