Towards Passivhaus Retrofits

When it comes to construction, for many years the governments focus has been upon new buildings, and the current drive for net-zero carbon homes by 2016 reflects this strategy.

But in terms of climate change and peak oil (the dwindling supply of fossil fuels which is leading to increased energy costs) one should really ask, is the problem new build?

The answer is both yes, and no. In the UK the replacement rate for existing stock is less than 0.1 percent per annum and the proportion of new build compared to existing building is less than one percent.
This means that our building stock is growing and that to replace all of the existing premises in the UK would take over 1,000 years.

The buildings that exist today will account for over 70 percent of the total building stock by the year 2050. As most of these buildings are poorly insulated, concerns about climate change and peak oil are worries that lie with the existing stock.

A recent study by the Empty Homes Agency compared the environmental impact of building new homes with refurbishing existing ones. The report, based upon UK case studies, shows that it is marginally more beneficial to refurbish existing buildings. The case studies looked only at the UK and not international best practice. If they had, then building refurbishment could have won with a landslide victory.

PassivHaus

Germany’s PassivHaus Standard is the world leading low energy, low carbon design with over 10,000 houses, schools, offices and premises built and performing to standard.

These buildings consume 90 percent less space heating energy than average building stock and about 75 percent less energy than current UK building regulations. The annual heating bill for a four bed, 1,300sq ft house designed to the PassivHaus standard is less than £63 per year!

European experience, backed up by numerous studies and research documents, suggests that the PassivHaus Standard is arguably the most cost effective means of economically addressing both climate change and the predicted shortage of fossil fuels. With this in mind, is it surprising that 20 percent of all new homes in Austria are built to the PassivHaus Standard?

Not only can the technologies that underpin the PassivHaus standard be used in new buildings, but they can also be used in existing buildings.

As one of only two British representatives who presented work at the international PassivHaus Conference I feel a strange mix of hope and anxiety about the ability of the UK to address the problem of sustainable building appropriately. Hope because the technology and experience exists; anxiety because whilst they exist, the vast majority of UK architects, builders and politicians remain ignorant to what can truly be achieved by undertaking the appropriate programme for the refurbishment of existing buildings.

Investment

In Germany over €1billion of public money per year is being invested in a comprehensive low energy and PassivHaus Standard building refurbishment programme, and a further €100million is being invested in developing new projects that are to be constructed to the PassivHaus Standard.

Why is the same not being done in the UK? Can the UK government afford to invest as heavily as the German government, without it affecting taxes?

If PassivHaus Standards were adapted in the UK, the energy savings would pay for themselves. The problem for construction companies is that the initial outlay for energy refurbishment is quite significant.

So how is the German government managing?

Aware of the benefits of energy conservation, it is acting to remove the cost impediment to the construction industry. It is doing this by providing a subsidy; in effect it is providing the grease to move the wheels.

The subsidy is not free. It takes the form of a loan with a very low interest rate; the total subsidy is repaid over a ten year period, after which time lenders are left with an annual energy bill that is 80-90 percent less than was previously the case.

The repayments mean that in the long run the scheme is cost neutral to the public purse. This is due to the economic viability of the PassivHaus technologies, with annual heating bills being reduced by a factor of 10.

Fuel poverty is a growing concern, especially with the rise in the price of fossil fuels. If adopted, in the UK this PassivHaus subsidy strategy could help to avoid, if not eliminate, fuel poverty within the UK for the foreseeable future.

If adopted at a regional level the German strategy would be a trailblazer, helping adoptive regions lead the way in developing a national programme that protects people from rising fuel costs.

Benefits

But this is not the only benefit that that would emerge from this radical programme.

• Firstly, if local construction companies were to undertake refurbishment work, the regions could capitalise from increased employment. The local workforce could also benefit from up-skilled staff, as they learn to design and build to the PassivHaus Standard, making specialist, regional builders a valued resource nationally.

• Secondly, if the regions were to use the subsidy strategy adopted in Germany to help develop a manufacturing base for PassivHaus technologies, then it would be possible to capitalise upon the programme, by manufacturing and supplying products and skills across the UK, Europe and beyond.

• Thirdly, the reduced amount of energy used to power buildings would means that the international utility companies, currently supplying the majority of energy to UK properties are neatly side stepped, leaving more money within the regions.

• Fourthly, there is a strong relationship between the incidence of asthma in children, one of the UK’s key health complaints, and poor indoor air quality. One of the benefits of PassivHaus is that indoor air quality is improved, thus a refurbishment programme could help to address concerns about health and well-being. The savings to the NHS alone could be significant.

• Finally, carbon emissions will be minimized, helping to protect the planet.

What the German government realised some time ago is that subsidising builders through long term loans to refurbish properties minimises, if not completely avoids the burden to the tax payer.

Once fully operational the €1billion subsidies system is reinvested every year in energy savings and every year it is paid back. What we have is a virtuous pot of ring-fenced cash that can be used to help create a win-win situation for both the bill payer, and the environment at large.

Arguably the UK could do no better that adopting a model that is similar to that used in Germany. This would not only protect the environment but also the bill paying public from the cost of climate change and increasing fuel prices.



Notes on the author:
Mark Siddall is an architect and a Certified PassivHaus Designer. He is also the sustainability champion for Devereux Architects and has conducted detailed research into low and net-zero carbon technologies. In addition to being one of the practice’s lead designers, Mark also provides consultancy, project enabling and education for clients, design teams and constructors. Currently he is working on what is understood to be the UK’s first major PassivHaus scheme (25 homes) and is providing consultation for the Riverside One Net-Zero Carbon development in Middlesbrough (a significant scheme for Bio-Regional Quintain).