The myth of ‘low energy’ buildings

Why do award-winning ‘green’ buildings so often have much higher energy bills than ordinary buildings?

Easy. Tick the boxes, install the sexy technologies, and make the claims for predicted energy performance.  Whatever you do, don’t go back and monitor how much energy the building actually uses and whether occupants are happy with what they’ve been given.

In truth, the UK’s failure to produce low energy, low running cost buildings that are warm in winter, cool in summer with good indoor air quality is a national scandal.

Building Regulations have included energy elements since the mid 1980s. Yet the culture of the UK buildings industry is all wrong. Few people, even those in the sector, are aware of the gap between predicted and actual energy performance. We don’t have a language for talking about it – and anyway, building user expectations are low.

The Retrofit for the Future (RfF) and Building Performance Evaluation (BPE) Government-funded programmes run by the Technology Strategy Board illustrate how dire the situation is. Preliminary analysis of 89 whole house retrofits – generously funded to deliver very low energy, low carbon homes – shows only a small proportion has reached agreed the targets they were given.  Over half the properties still leak heat, some of them very badly; a few are leakier after the refurbishment than before.  Many are using almost as much energy  ordinary homes that have not been refurbished.

Analysis of the performance of a range of new buildings – homes, schools, offices and health centres – gives an even more depressing picture. Most buildings surveyed had one or more of specification, design, installation and commissioning flaws. Measurement of actual energy used was wholly inconsistent. Evaluation teams are shaking their heads at the scale of the problem.

It’s Time For Action

With energy prices rising inexorably, the time has come to take the energy performance of buildings seriously.  We need to monitor and measure energy use and carbon emissions to find out what works and what doesn’t and to share this with the property industry and its customers. In short, we should create a Buildings Knowledge Hub.

The Hub would gather, analyse and disseminate good quality buildings’ energy data and develop benchmarks for different building types in order to evaluate performance. It would also coordinate information and education activities and ensure energy efficiency is judged by an agreed standard. The era of box ticking must end.

There is some good news. The government’s Green Construction Board is making some real progress. It has commissioned work aimed at establishing monitoring and measurement protocols and to agree a common language for talking about energy and carbon performance. It has reviewed the need for an existing buildings hub, and is exploring how it can place data of consistent quality at the heart of a knowledge hub for both new and existing buildings.  The Department for Communities and Local Government is funding a project to close the performance gap in new homes.  Establishing its success will also depend on good quality monitoring and measurement.

The government recently launched the Green Deal for refurbishing residential and non-residential buildings. But given the gap between theory and reality on energy performance, this flagship policy is in danger of being discredited.

A Buildings Knowledge Hub should be set up without delay. The mistakes of the last decades must not be repeated. Green buildings must be for real – it’s the only way to tackle those soaring energy bills.


6 thoughts on “The myth of ‘low energy’ buildings

  1. Liz,
    Knowledge is the fuel for energy efficiency in buildings, and I think BuiltSpace could be described as your Building Knowledge Hub concept. Our belief is that a collaborative approach that allows building industry professionals to work together, given energy, asset and service/use information knowledge about individual buildings will drive efficiency in both operations and energy efficiency.


  2. Anyone who wants to review the full set of findings from Retrofit for the Future should visit You can download our ‘first cut’ analysis report, and even the raw energy dataset for the properties analysed in the report.

    The TSB is very happy with the many beneficial outcomes of the programme. Every home we analysed has significantly lower energy use and CO2 emissions, when compared to the national average. The vast majority of occupants have reported that their homes are better and more comfortable to occupy.

    It is true that not many of the projects exceeded the stretch target of an 80% CO2 reduction; however, we should keep in mind that these homes used 2008 solutions to aim for the 2050 target.

    The difference between ‘targeted’ and ‘achieved’ performance is an industry-wide issue that we hope our dataset can inform solutions for.

    We want to ensure that maximum learning is gained from the real performance of each home in the programme. Please get in touch with me if you have ideas for how we can do this!

  3. I am so glad to have found your blog! Homestar Building Performance is in the home energy assessment industry. We actually have certified programs and tests in place that we use here in Northern California to not only detect energy leakage in built homes but we have the software where we enter all of the homes data. The on-site energy assessment take us 4 hours, data entry another 1-2 hours, then we meet with our customers and provide an energy assessment report to our homeowners! At that point they can make intelligent accurate decisions on what their home needs in order to envelope their homes.

    I like to advise that our Homestar Building Performance home energy assessment be done prior to any solar installation. Finding out where and how a home can best be retrofitted or upgraded and then enveloped will in most cases reduce the amount of solar panels needed to further reduce energy costs.

    The only thing we are having a struggle with is educating Realtor’s, homeowners, buyers, etc. to see the value in having a home energy assessment done! Our ‘new built’ codes here in California are becoming more energy conscious. For example one city has just mandated that all new residential builds will have solar.

    What I predict is a market change. The value of a “green” home is going to be competitive with pre-built residential homes that are not certified “energy efficient”. New buyers are going to demand to see what the utility costs before purchasing a home and will be smart to want to know if it is certified energy efficient (which also determines the comfort of a home). As buyers are educated their buying values will also change. Why not have an energy assessment done on a home prior to purchasing … then require upgrades to be done … and move into a comfortable smart energy efficient home? (Vs.vs. to sell!!)

    Our California Energy Commission is working hard to bring residential homes up to higher energy efficiency standards. But there is still much to be accomplished.

    Angela Christianson
    Homestar Building Performance
    Management & Marketing

  4. Pingback: Blog post by Liz Reason on the Myth of ‘Low Energy’ Buildings | Changing more than lightbulbs

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s