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Improving Existing Housing

CLG recently published their 7th committee report, HC 432-I: Existing Housing and Climate.

An excerpt from Zero-Carbon Solutions' response to this excellent report is, in the words of MD Niels Bjergstrom, reproduced below:

I have a few comments which you may wish to consider in future work:

1. I fully concur with Professor Anne Power when she says: follow Germany's lead. I would add Scandinavia to this. This is true both technically and to a large extent, politically. Technically, only very limited domestic research is required. The knowledge as well as the technologies have already been developed over many years in Europe and are readily available. In many cases, including restoration of listed buildings, these technologies and many policies, can be used directly "as is".

2. One important policy we should follow is that of refraining from specifying calculation methods in legislation and rather measure results like they do in Sweden for example. SAP should be scrapped. It is unsuitable for very low energy buildings (which should be calculated using the Passive House Planning Package PHPP), and it contains too many errors, both in boundary conditions and mathematical methods. SAP, and BRE's fight to retain its monopoly position, have de facto served to hinder development towards energetically improved buildings and are still doing so today (as exemplified e.g. by the position of SAP Appendix Q, which prevents many of the most efficient ventilation and heat recovery units from being used in the UK - these are typically manufactured by small companies specialising in the passivehouse area and not interested in investing large amounts of money in carrying out tests specific to the UK market. Such test requirements should be abolished and European tests accepted fully).

3. With regard to listed buildings and conservation areas these present problems as pointed out in the report. The idea that we should be living in a large open air museum rather than giving our young architects challenges and opportunities also outside large urban areas, has been taken too far in my opinion. The conservation drive should be scaled back and reevaluated.

If we look at German reports, e.g. from the Fraunhofer Institut, we can learn that many relevant techniques have been developed and documented through measurements over several years, which allow listed buildings to be updated to an energetically acceptable level while at the same time improving these, reducing maintenance and running costs and securing the permanence of these buildings. Innovative solutions often have to be found in individual cases - of course you can't just implement air tightness without at the same time introducing controlled ventilation for example. It is also imperative that the airtight layer as well as the borders of the heated envelope are chosen correctly, and doing this requires people capable of applying building physics to individual cases. In particular in cases where for architectural reasons you need to use a combination of external and internal insulation this becomes tricky.

In conclusion, a policy combining the lifting of listings and conservation orders in cases where these are not really warranted with intelligent and sensitive upgrading of buildings that do deserve this treatment, is called for. Retaining 4-5 million poorly insulated buildings is not a palatable option, and frankly: many listed buildings have the architectonic and historic interest of a boiled potato.

4. With regard to energy production there are a number of extremely important issues which do not seem to be clearly stated, perhaps not clearly understood. The overriding principle is not to switch from polluting to sustainable energy generation technologies - that is a secondary goal. The primary and driving principle is not to use the energy in the first place - that way you do not need to generate it. So, with regard to buildings the first three things to be done are: insulate, insulate, insulate. Fitting small wind turbines to non-upgraded buildings make no sense at all. It is not only a waste of money but, worse, it serves to misdirect efforts.

As an aside, measures such as cavity wall insulation are good but insufficient and with our current technical and scientific knowledge, not cost effective. Hence these older insulation and energy efficiency improvement strategies should only be supported in cases where up-to-date methods for some reason can't be applied. Current methods typically include applying external complete-insulation airtight envelopes, triple-glazing and controlled ventilation, combined of course with suitable loft insulation (up to 600-700 mm thick). These techniques are easily applied e.g. when upgrading whole rows of terraces or individual houses, with more difficulty in case of semi-detached or individually owned terraced houses because of issues of ownership (a primary advantage of applying external insulation is that it will automatically remove many cold bridges - if the insulation has to be stopped at party walls removing cold bridging requires additional efforts).

Back to energy generation. We should adapt two national and clearly stated policies:

4a. We support and further de-central (individual) energy generation. This will bring a whole raft of advantages, including many new job and entrepreneurial opportunities. It will, if carried through quickly and correctly, alleviate the need to build new large power plants and ugly wind turbine parks, and allow us to shut down inefficient and polluting plants faster. From the point of national security it will quickly reduce our dependence on natural gas and other energy carriers from potentially hostile foreign suppliers. For this reason (national security) alone this policy should be introduced asap! Thirdly, it will increase supply security in a period of changing climatic conditions.

To further this goal several secondary policies need to be instituted, e.g. attractive feed-in tariffs (which should be paid for by the large polluting energy generators, not the tax payers) and long-term guaranteed low-interest loans assuring pay-back on e.g. photovoltaic installations - German policies can be emulated here.

4b. We introduce hydrogen as the primary energy carrier nation wide (electricity being the secondary). This is a bold step but it makes good sense for a number of reasons. A main issue with wind power, which the government seems to favour for some reason (the science of which is not clear to me), is that it needs to be coupled to energy storage solutions in order to be efficient. If this is not the case the power output from these turbines can only be used when there is an immediate demand - which is not necessarily when the energy is available. In Austria they use the potential energy of water as energy storage by using the output from wind turbines to pump water to high-lying reservoirs when this electricity is not required for immediate consumption. When electricity IS required, the water is used to drive hydraulic electricity-generating turbines, utilising wind power whenever it is available. This obviously leads to reduced investment is both wind turbines and hydraulic power installations.

In this country we cannot easily do that for topological reasons. However, off-shore wind turbines are surrounded by water, which can be electrolysed to produce hydrogen. This in turn can be pumped ashore and used, even distributed in the current gas network and used in appliances after small changes ('city gas', which was the preferred energy carrier before the introduction of natural gas, contains a high proportion of hydrogen). De-central (local or for individual homes) power plants, e.g. powered by photovoltaics, even very small ones, can be based on the same principle, thus utilising the sun's energy whenever it is available, to generate hydrogen. Using fuel cells the hydrogen can be converted back to electricity when needed. Even considering conversion losses the country could probably be powered by solar and wind energy alone. Full-scale trials in domestic setting using these technologies are currently underway in Japan, and Germany is striving towards commercially viable solutions and products by 2010. Hence, this area is still wide open and a potential rich source of UK jobs and export potential if we act quickly and decisively.

Thus, using these principles my 'dream house' will not be connected to any utilities, perhaps with the exception of water, it will be energetically self-sufficient - and produce enough surplus hydrogen to cover the family's transport needs through a car fitted with a fuel-cell.