Call us on 0875 221 2232

  • sustainability | carbon emissions | water efficiency
  • retrofit | fuel poverty | energy efficient | energy costs
  • Solar PV | feed in tarriff | reduce energy costs |
  • Carbon emissions | fabric efficiency | fuel poverty | energy costs | energy demand
  • Resources | Carbon emissions | timber | resource management
  • Efficiency | flooding | energy costs | bills |
  • Solar Thermal | Feed in tariff | RHI | energy costs | lower bills
  • fuel poverty | on-demand heating | energy costs |

Baker Homes Blog

If Volkswagen did homes...?

Posted by John Stapleton on 23/10/15 24:01

In April, Which? magazine splashed with a report that many people who drive a new car may have long suspected – the mpg given in the handbook does not quite fit with the number of times they were having to fill up. And three weeks ago the Volkswagen Group dropped its bombshell – test results for levels of dangerous nitrous oxides cars emitted by its vehicles had, in effect, been fabricated.

How many miles per gallon does your home achieve?

What is it about the homes we live in that makes it hard to imagine the same level of scrutiny being applied? VW's cars were emitting between ‘10 or 40 times’ acceptable levels of pollution. Which? thought the disparity it uncovered could be costing car owners ‘hundreds’. This could also easily be the price of the ‘performance gap’ in homes.

Of course, comparing cars and homes is not entirely fair: they are used in very different ways and homes have a multitude of functions which cars do not. It is relatively easy to adjust your driving style if that is a factor pushing up fuel consumption. It is much harder to do the same for your home. Use of energy there is a much more complex business. ‘Occupancy’ means not just the number of people that live in a home but the amount of time they spend there – which, of course, varies for many reasons. Similarly, the number and type of devices that are run – fridges, televisions, gadgets. Moreover, people do not imagine themselves using energy. They see themselves living their lives, doing the things which they need or want to do. So the interaction between people and homes is not always as predictable as it is when driving a car.

Nevertheless, neither cars nor homes are doing what they said they would on the tin. Even when performance of homes is noticeably below what was expected, it is not always clear what the root cause is. Can we attribute it to the building itself or the behaviours of the people that live there?

The Zero Carbon Hub have been undertaking research with industry to identify what needs to change at the macro level. But it is just as important for housing providers who are investing in new homes, often designed to a specification above the minimum, to understand what is going on in their stock.

The most common reasons for homes not delivering the expected savings are threefold:

Low energy literacy in the supply chain – understanding the interaction of building fabric and energy is essential,not least helping to inform what features will work and which will not.

Poor detailing by contractors – unfamiliar techniques are a potential stumbling block. Problems such as ‘thermal bridging’ are magnified when the detailing is not up to scratch.

Behavioural factors – there are myriad reasons why energy efficient homes may not be delivering the goods for occupants. An example is mechanical ventilation systems that are switched off or covered up by residents.

The holy grail for homes is a specification based on outcomes, not means – meaning contractors and the supply chain are focused on getting it right first time round. Such a world is not a million miles away. But until we have a better understanding of what goes wrong, and why, there is no basis on which to sit down with all those involved in a scheme to sort them out.


Riverside spend millions each year building new homes each year – as well as improving existing ones, such as those that Chief Executive Carol Matthews inspects here.

Get involved – research into the performance gap

The National Energy Study 3 is Baker Homes’ contribution to ensuring that we do not see the failure that VW experienced in our homes. We are looking for developers or developing social landlords to lead the sector by volunteering new build homes for research.

Kevin Hubbard, Quality and Value Development Manager at Riverside, explains why they are participating:

“As a developing housing association who aspire to build to standards above the minimum, we want to be sure that the extra investment we make is benefitting residents as much as it should.  Getting to the bottom of any ‘performance gap’ of our new build homes, whether that be down to technical issues or in-use factors, is of real importance to us.

We plan to use the findings to initiate a dialogue with all those involved in the supply chain to ensure that future developments are both fully fit for purpose and inexpensive to run.”

Benefits of participating

  • A specific in-depth analysis of your homes with recommendations for remedying issues
  • Be part of a nationally important piece of research
  • Basis on which to demand more from developers and transition towards an outcomes-based approach to design and build

For more details of how you can get involved in the National Energy Study 3 please email

A version of this article appeared in 24 Housing magazine.

Topics: National Energy Study, Housing Associations, Energy Performance, Energy, Bills, Performance gap, Housing

SHIFT Awards 2015, the UK’s sustainability awards for social landlords.
10th November 2015 | the Palace Hotel | Manchester
Submit your entry below.


Post a comment