Defining the context for the 'Great Low-carbon Refurbishment Challenge'

[Andy Simmonds]

I am currently engaged in refurbishing my own family townhouse to near Passivhaus (AECB Carbonlite Step2) standard using a small team of conventional builders - this project will become a case study funded by Industry and disseminated through several Knowledge Exchange networks. I am aware that it may be that this level of refurbishment is not actually an appropriate refurbishment response in the context of this part of Hereford! However the integrated strategic thinking needed to identify what level of refurbishment is most effective and cost effective and appropriate for each area/parish/street etc has not yet been carried out. This thinking is crucial to properly reduce emissions from the existing stock reliably and affordably.

To date the AECB has described the future importance of the AECB Silver and Passivhaus standards in the refurbishment context, but the missing level of thinking suggested above is that required to properly define the refurbishment context - from a UK context right down to a parish by parish and even a street by street level.

I feel that it is critical that detailed strategic planning explores the localised possibilities for the cost-effective use or production of locally distributed low carbon heat or fuels for use in buildings, before defining energy efficiency measures appropriate. For example in Herefordshire where I live, the existing building infrastructure can be analysed in relation to existing sources of waste heat from commercial and industrial premises, opportunities for heat generation from agricultural byproducts and planning for strategic development of combined heat and power. In addition, for example, scope exists for the use of proven (successful examples exist e.g. in Denmark) low-cost, low-carbon heat that can be produced from currently 'overlooked' technologies (on this intermediate scale) such as solar thermal panels (combined with large insulated underground hot water tank) installed on poor agricultural land adjacent to towns. Heat from all suitable sources is distributed via a District heating system. There are many examples and possibilities of low carbon initiatives, but they are currently being adopted in an ad-hoc and piecemeal fashion, led by an un-integrated and badly prioritised goverment grant system.

A professional and integrated assessment of an area's potential low carbon heat and power resources would provide a long term framework at local community level and would help council's, businesses and  citizens in each area make sensible long term plans as well as encouraging sensible and effective low carbon government grants and commercial financial incentives. This community led planning work could be led by Rural Community Councils working with the appropriate Voluntary, Statutory and Private agencies.

As a result the easy wins (the hard to heat system-built housing estates with tenants in fuel poverty for example) could be identified as being decarbonised using EITHER agricultural byproducts / local waste heat / etc as above  OR refurbishing the estate to Silver or Passivhaus standards in order to reduce GHG emissions, increase comfort and health conditions and reduce tenant's fuel costs to an affordable level. The more difficult challenges - e.g. reaching individual homeowners and private landlords - would also become easier.

Without this contextual, integrated, community based approach it seems to us unlikely that the UK will either manage to, or afford to, refurbish its existing building stock - to the levels of low carbon performance required - successfully.

I am interested in others' views.......

[fostertom]

Swingeing fuel price rises will drive low-fuel refurbishment like nothing any govt programme, tax break or regulation has achieved so far. The demand will be intense, once households and businesses begin to really feel the pain. Unfortunately that's only about reducing fuel bills, so says nothing directly about embodied energy - except inasmuch as high-fuel-content materials and processes will begin to price themselves out.

[Dave Howorth]

I'm with Tom on this one.

And I've just returned from an expedition looking for a building plot, where the main obstacle seems to be shackled and incapable planning bodies. So I'm dubious about any politically-dependent initiative - either local or national - until their well-rehearsed problems are overcome.

Sorry to be so negative Andy. I suppose one bright spot is that the HIP/EPC failure is now officially acknowledged if I understood the recent CIBSE call for comments correctly.

Cheers, Dave

[Mark Siddall]

Hi Andy,
I agree that that with regard to existing building stock, in order to achieve the >70% carbon reductions, neighbourhood systems need to be developed and integrated along with appropriate levels of refurbishment of the existing stock.

The question that I have in my mind is what is the appropriate level of refurb? The report “U-Values For Better Energy Performance Of Buildings”* by ECOFYS for EURIMA makes for compelling reading when developing an appreciation of the cost effective levels of insulation for both new and existing buildings (turns out that the economic U-value is roughly the same in both instances).  See
www.eurima.org/uploads/ModuleXtender/Documents/88/documents/EURIMA-ECOFYS_VII_report_p1-65.pdf

*It is acknowledged in the report that the study fails to fully engage with whole systems engineering and as a consequence fails to eek out that last little bit of affordability that would establish PassivHaus standards of U-value.
One observation that I have about the report is that it talks of U-values in isolation and does not seem to consider thermal bridging. On this basis I believe that the U-values in the report should be considered to include the Y-value of the thermal bridge (thus the reports cost effective U-value = Fabric U values - Y value)

Refurb
I think that buildings should be made/refurbed to consume a little energy as possible rather than being very tightly synchronised with a neighbourhood system. The reasons for this are several:

1) In a finite world, with an expanding global population, we need to manage our resource and minimise consumption
2) Because of the properties of insulation is it is not economic to return to upgrade the thermal performance of an already refurbished well insulated building. (Do it once. Do it right.)
3) By reducing energy consumption to as low as low a level as possible we create future proofed building stock that is not bound into inefficiencies of current technologies (which could occur if current generation technologies and fabric performance were tightly integrated.)
4) Current limitations in technologies need to be recognised; especially in relation to co-generation. For space heating only then neighbourhood SHW may be an affordable option however the use of SHW does then limit the range of solutions that can be used for generating elec i.e. it excludes low carbon solutions such as co-gen and required the jump to wind/PV and other renewables (which whilst no bad thing may not be the most affordable solution at present).

Admittedly some building types using certain building technologies will be more difficult to refurb to high standard and here neighbourhood solution have an important role. These physical limitations could in turn be usef to inform the selection of co-gen technologies.

Co-gen Conundrum
A key consideration when integrating co-generation is the ratio of electricity to useful heat. It can be argued that it is important to get the right balance between generation ratio and the required thermal performance of the buildings. I do have some concerns about this approach. My primary concern hinges on the appreciation that because of the properties of insulation it is not economic to return to upgrade the thermal performance of an already refurbished insulated building; thus in 25 years when the co-gen plant is to be replaced you are tied into a technology that produces the same ratio of electricity to useful heat that was established by the old technology.

By endorsing the building refurb solution it means that I accept that at a systems level the co-gen technology may be less efficient per unit of bought energy but it does mean that when replaced a more suitable technology can be selected at a given point in the future. (Under this option, in the short/medium term, carbon emissions from the co-gen would be no greater than would otherwise be the case but in the long term they can be reduced even further.)

One also has to be mindful that, depending upon the fuel mix of the national grid, if not judged appropriately, then carbon emissions can actually be increased when using SHW in conjunction with co-gen.

Industrial Ecology
Here I am picking up on your point about harmonising with waste heat from commercial and industrial premises. This concept would require some very carefully planning but would be of great benefit.  My main queries/reservations are:
1) How does one establish a suitable district grid that these energy sources can contribute to and how could you meaningfully harvest the energy?
2) Such a concept will have to bear the cost of a back-up heat supply to cover eventualities such as businesses collapsing, and no doubt all will be driven by regulation to be come more energy efficient thus removing the energy supply to homes etc.

Culture Change
This is the big one. Within the UK we need to encourge changes within the utilities market that will enable the development of appropriate neighbourhood solutions. This will mean the restructuring of regulations and the like. Only once this process is underway will the planning process be able to enguage meaningfully with these concepts.

So goes my two penny worth anyway.

Mark

[David OLIVIER]

I suggest storing the industrial waste heat in a giant insulated tank in the ground, as proposed for solar heat in Denmark. If it's worthwhile to store solar heat, which has a significant production cost, for a season, it's surely worthwhile for reject heat. That storage potentially gives you 3-6 months after a business collapses to find a new source of (more expensive) heat.

AFAIK, most of Gothenburg, Sweden is heated by the nearby oil refineries (which are owned by Shell). Future biorefineries, which convert wood, bamboo, elephant grass or straw to premium fuels, will produce more waste heat per ltr/day of output, due to the lower quality and chemcal complexity of the input compared to crude oil (oil refinery efficiencies are almost 95%). So this is likely to be one of the avaiilable sources of heat.

It would be good if we could persuade William Orchard, Orchard Partners (AECB member) to join in this thread. He designs DH & CHP systems (and the heating systems linked to them) for a living. I think he helped to renovate many of the DH systems in Lithuania, so they now perform closer to those in Denmark (the world leader in low-cost CHP/DH, with 65% of buildings heated this way and another 15-20% reportedly available to this form of heating as Danish North Sea gas supplies run down).

If buildings are heated this way, the appropriate insulation level may be lower than Passivhaus, but most modern buildiings in Denmark meet the Silver std. There've been found to be ways to improve the economics in low-density areas or in areas where individual buildings have lower heat demands. There are a few Passivhaus buildings in Vienna connected to the central CHP plant(s) - this may be justified because a heat main runs through/near those areas anyway. Also Kronsberg, Hannover is entirely heated by CHP, although all the homes are Low Energy (approx Silver) or Passivhaus.

As far as I can see, thermal refurb. of the entire urban UK stock to a weighted average of Passivhaus - listed buildings and all - would be extremely demanding. However, to bring cities up to a lower average standard, possibly on a par with Silver, might be feasible.

It isn't a very good idea to plan to heat different neighbourhoods by their own small CHP plants. The exergetic efficiency (see 2nd. law of thermodynamics) roughly doubles as one moves from very small 10 kWe generating plants to plants in the size range 30-200 MWe. The move in other countries, over time, has always been away from small CHP plants in the basements of flats, hospitals or hotels towards pipes which connect all these buldings ("point loads") to the city's CHP plant(s).

David.

[peter warm]

Im thinking all this low carbon supply stuff is frankly, bollocks, and we need to first learn how to build the fabric of true low energy buildings before we all get caught up in the gadget trail.

I cant help remembering the site analysis we did for a 120 house site in London, where the insistance on biomass powered central boilers meant that we eneded up delivering less heat to the houses than the heat loss of the distribution system, and that was near PH insulation with a full preinsulated heat main.

Off to work on the CLP PH lecture trail....

pete

[Mark Siddall]

Can't help but agree with you Pete. getting wrapped up in large neighbourhood systems is a potential distraction. As I said earlier fabric first. On a project for 25 PHs that I'm currently working on we considered a site wide district heat system but due to concerns about system wide losses (and some phasing problems) we ended up opting for what can only be called a micro-neighbourhood system (a condensing boiler on one end of each terrace.)

Good luck on the CLP training, hope all goes well (or depending upon when you read this: hope all went well).

Mark

[David OLIVIER]

The means to reduce heat losses when heat mains are laid to low-energy buildings were analysed some time ago as Denmark has had very highly-insulated buildings (by UK standards) for a long time, often masonry walls with 150 mm cavities or slightly wider (cavities were 100 mm wide in 1975). I think to describe CHP/DH as a gadget is bizarre as it actually reduces the number of moving parts (which go wrong) by 99%, given that directly-connected buildings need no pump.

Today's heat distribution losses in Denmark at the current heat demands are about 8-12 percent. With optimally-insulated pipes and valves, they'd generally all be lower than 10 percent. With a few refinements more, they'd be 8-10 percent even for substantially lower heat demands; i.e., Silver Standard to Passivhaus range.

If gas is the chosen energy vector for developments planned now, both new construction and eco-refurbishments, a well-justified question is what will we replace it by as gas runs down? Gas won't run out overnight, as is sometimes implied but nor is it likely to be available in anywhere near the current quantities in 2030-40. (Go to www.theoildrum.com if you want chapter and verse on peak oil, gas and coal).

David.

[Andy Simmonds]

This resolution now agreed by the EU Parliament is being proposed to the EU Commission and relates to this thread I think:

(This is extract from full resolution that relates to Passivhaus standard): -to propose a binding requirement that all new buildings needing to be heated and/or cooled be constructed to passive house or equivalent non-residential standards from 2011, and a requirement to use passive heating and cooling solutions from 2008;

http://www.passivhaustagung.de/Passive_House_E/PassiveHouse_directory.html

For you Europhiles the full text of resolution is at bottom of this page: http://www.europarl.europa.eu/oeil/FindByProcnum.do?lang=2&procnum=INI/2007/2106 and I have copied i t below!

31/01/2008 - EP: non-legislative resolution      

The European Parliament adopted a resolution based on the own-initiative report drafted by Fiona HALL (ALDE, UK) and welcomed the Commission Communication entitled 'Action Plan for Energy Efficiency: Realising the Potential'. The resolution was adopted by 592 votes for, 26 against, and 30 abstentions. Parliament considered that a target of improving energy efficiency by over 20% by 2020, in addition to any improvements due to autonomous structural or price effects, was entirely feasible technically and economically. 

However, Members noted with grave concern that implementation by Member States of existing legislation on energy efficiency was incomplete and behind schedule. Directive 2002/91/EC on the energy performance of buildings had been properly transposed by only five Member States. Implementation by Member States of Directive 2004/8/EC was late and far from perfect on the international market. Members censured the failure to put in place the number of Commission officials needed in order to ensure that both the Action Plan and the energy efficiency legislation on which it builds were implemented fully and promptly. They went on to deplore the fact that, of 21 Commission actions scheduled in the Action Plan for completion in 2007, only three had been fully implemented by 1 September 2007. They also deplored the severe slippage in the timetable for the adoption of minimum energy performance standards for priority product groups.

Parliament censured the failure of many Member State governments to prioritise prompt transposition of energy efficiency legislation, despite rhetoric about tackling climate change and reducing EU energy imports. It called for a frank assessment of the capacity shortfalls and other barriers which had led to inadequate implementation of energy efficiency legislation. There was also a widespread lack of simple information on energy efficiency at the point of need, which might arise suddenly (e.g. when a domestic appliance or other equipment breaks down) or be connected with particular events (e.g. moving house). A lack of attention to the practical needs of citizens was undermining many energy efficiency schemes. ICTs should be promoted as a key element in driving forward energy saving in various sectors such as transport, construction, energy and manufacturing.

Equipment and appliances: Parliament welcomed the strategy of adopting minimum energy performance standards and called on the Commission to establish them by 2008 for air conditioning and all types of television set top boxes. Members particularly asked the Commission for the following:

-to explore ways of advancing research into LED lamps and of increasing their use;

-to establish timetables for the withdrawal from the market of all the least energy-efficient items of equipment, appliances and other energy-using products, such as patio heaters;

-to come forward with a 'one watt' stand-by performance requirement and an analysis of the potential energy savings to be made from both minimising and eliminating non-essential stand-by mode consumption, particularly passive stand-by;

Building performance requirements: Parliament urged the Commission to expedite infringement procedures against those Member States which had not properly transposed or implemented Directive 2001/91/EC. It called on the Commission to revise Directive 2002/91/EC so as to include from 2009 all buildings requiring heating or cooling, regardless of their size, and also to do the following:

-to have regard to the fact that cogeneration (micro combined heat and power) boilers are by far the most efficient, and to set minimum performance requirements for boilers accordingly;

-to propose a binding requirement that all new buildings needing to be heated and/or cooled be constructed to passive house or equivalent non-residential standards from 2011, and a requirement to use passive heating and cooling solutions from 2008;

-to consider the gradual introduction of district heating and cooling grids for all buildings to reduce fossil fuel use in heating and cooling by utilising the losses occurring in the transformation of energy;

-to consider architectural solutions for passive heating and cooling, such as construction structures with thermal properties, when considering taxation and other measures for promoting energy efficiency;

-to promote district cooling from renewable sources of energy as an efficient alternative to meeting the growing demand for comfort cooling;

-to create a transparent database of measures promoting energy efficiency in buildings, in particular financing measures, in the interests of exchanging best practice and of public information. 

Power generation and distribution: NEEAPs must include an increase in high-efficiency cogeneration. Member States were asked to move to the holistic planning and fostering of electricity, heating and cooling supply, and more generally to promote measures to encourage the use of small-scale and micro cogeneration. The Commission must look unfavourably on NEEAPs which fail to do this. Parliament asked the Commission to pay greater attention to the heat market, as heat represented the largest share of energy consumption, and to instruments (urban planning, heat mapping, investment incentives) that would allow the recovery of surplus heat from renewable sources through the development of district heating and cooling infrastructures. It also asked the Commission to extend the scope of existing financial incentives to developments which enable energy produced from renewable sources to be fed into existing networks set up for fossil fuel energy.

Transport: Parliament called on the Commission to set minimum energy performance requirements for all transport modes, including public transport. The Commission was asked to launch an initiative specifically concerning urban transport and the issue of integrating climate protection, energy saving and public health in a sustainable mobility policy for towns and cities. EU cities were urged to consider measures to reduce the CO2 emissions, for example by congestion charges. Furthermore, Parliament called for Directive 1999/94/EC to be amended in such a way as to provide for car labelling on the clear A to G format used in appliance labelling. A minimum of 20% of any space devoted to the advertising and marketing of new cars should provide information on fuel efficiency and emissions. The Commission was asked to devise a framework strategy to facilitate substantive improvements to the efficiency of urban and suburban public transport.

Financial arrangements and regional policy: Members called on the Commission to raise from 3% to a minimum of 5% the proportion of structural and cohesion funding which should be spent on improving the energy efficiency of existing homes. It regretted the complexity of much EU financing for energy efficiency, noting that the lack of simple and accessible funding constituted a huge barrier for small and micro businesses. Parliament urged all relevant parties to take advantage of the funding available under the Seventh Framework Programme, the Structural Funds and the Competitiveness and Innovation Framework Programme/Intelligent Energy Europe, and urged the Commission to respond generously to calls for funding for research into energy efficiency. The Commission was also asked to support state aid rules that were more favourable to energy efficiency measures (such as eco-innovation and productivity improvements).

Taxation: the Council was asked to encourage the Member States to apply a reduced rate of value added tax on labour, materials and components which improve energy efficiency in buildings. It was also asked to ensure that the overall tax system reflected the aim of improving energy efficiency in buildings. The resolution noted that taxation fell within the competence of Member States, and that taxation measures chosen by Member States might be an element of all NEEAPs. It advocated internalisation of environmental costs. Member States were asked to introduce incentives to encourage households, micro-businesses and private landlords to pursue energy-efficiency measures and buy energy-efficient products. Tax incentives could be available for the demolition of energy-inefficient buildings, when combined with the construction of new energy-efficient new buildings.

Changing behaviour: Parliament called on the Commission to increase research into behavioural economics and human decision-making so as to help tailor future energy-efficiency information campaigns (such as the Sustainable Energy Europe Campaign). Since energy efficiency started at home, it felt that EU institutions could take the lead by requiring exemplary energy performance standards to be set for all EU institution buildings, as part of a wider audit of energy use by the institutions which should embrace working and travel arrangements, incentives and locations, as well as equipment and procurement. It also called on the Commission and the Member States to organise, on an annual basis, a European Action Day on Energy Efficiency.

The global dimension: Member States and the Commission must enhance international cooperation in the energy-efficiency field so as to ensure that new regulations did not fragment the global market. It acknowledged the ongoing work at technical level on shared energy-efficiency standards, particularly with China, but was concerned that this work was undermined by the lack of coordination between Member States. Lastly, it noted the widespread concern that Russia would not be able to meet its domestic and contractual gas demand, and urged the Commission to commit greater resources to the EU-Russia Energy Efficiency Dialogue, with particular attention being paid to the upgrading of Russian district heating networks and to the utilisation of gas currently flared on oil fields.

[Barry Johnston]

On the Low-carbon Refurbishment Challenge one context could be accuracy and transparency as a starting point.

The BRE drafted a consultation on this topic which closed on 6 March 09. I read it and it I has some glaring errors. For example it incorrectly defined all solar thermal systems as zero carbon when they are not. It proposed fitting twin coil cylinders even though does not comply with HSE's L8 Legionella guidance. It would be inadvisable to adopt this approach.

I tried to attach the draft consultation which was apparently drafted by BRE, but it sems to be too big to load. If you want an annotated copy, please do ask me. It seems a bit sloppy. If it is of interest, here follow some of my comments on the draft in more detail:

Page 35, Table 11 contains incorrect terminology regarding solar thermal and its carbon footprint. Most solar thermal is low carbon, not zero carbon. Mains pumped solar has about 20% operational carbon clawback according to DTI funded research and some other studies. At present zero carbon solar thermal only includes thermosyphon systems and PV pumped systems. Perhaps the benefits of zero carbon solar thermal should be explained? After all, we will be unlikely as a country to be able to reduce our emissions to even 20% of today's if zero carbon solar is not prioritised in such guides over conventional plug-in-to-the mains low carbon solar (with its 20% carbon clawback.).

Page 35 in section 4.1 Para 1 To say that Solar thermal is also known as solar hot water systems is incorrect. Solar hot water is merely a subset of solar thermal. For example solar air heating is still solar thermal. Can this be fixed please?

Para 2 The dubious claim "Evacuated tube collectors are more efficient than flat plate collectors, especially in overcast conditions, and are ideal in situations where the available unshaded south-facing roof is limited. Where roof area is not a constraint, the additional expense of evacuated tubes puts both types of collectors roughly on a par in terms of cost effectiveness." seems like an unjustifiable commercial plug for evacuated tubes - based on myths. Myth one is about efficiency. This only stacks up if absorber area is considered. If the gaps between them, all their manifolds etc are included then they are similar to flat plates.

Secondly the area of an installation probably only matters in 1 or 2% of homes anyway. The guide does not point out that roof are is very rarely limiting for solar thermal installations. Perhaps it should? Take a normal solar installation of say 2-6 sqm. How many garden shed dwellers do you know?! Roofs are by necessity larger than the floors below because roofs overhang - and they are tilted.

Para 3 on Legionella appears to support Para 158 of HSE's Legionella code and guidance L8. But twin coil solar cylinders which are suggested in the next paragraph and elsewhere, do not comply with L8. Please choose one of the other, bearing in mind public safety. One solution would be to suggest thermal stores only. Of course, you could also include solar cylinders with the backup heaters at the bottom. Some lobbyists in the industry may tell you this does not work, but we have 10 years experience that this safer approach works just great.

Page 40 and 41 bottom parts of table. There are difference types of cylinder insulations each with differing insulation capability. Please state a performance of cylinder insulation not simply a thickness! You state performance for other insulators. Is the solar / plumbing industry really so backwards that it needs the EST to describe measure insulation in mm rather than the correct units?

Page 52 in "Future proofing" 8.5 Concerns about twin coil cylinders again. Pleased to see reference to thermal stores, but it is nonsense to imply that other types of hot water store cannot be taken to say 80C. They can with a blender valve.

Page 36 part 4.2 is over-specific in saying "As with solar thermal panels, PV should face close to due south, although any orientation between south west and south east should be within 5% of the maximum output". Please give solar thermal, as least more latitude and allow E and W, as discussed below. These are a lot better than nothing. This links to...

Page 53 in "Trigger points" 8.6 In the UK, There is more mythology in the section on on solar panels and roof pitch. While grid-connected PV systems may well need to be positioned to maximise annual performance over a year, solar thermal systems are best designed to minimise the buying in of fuel. This is because they ar enot grid connected and designing for a summer surplus is counterproductive. This means they rather than creating a summer excess which cannot be used (relatively shallow panels do this best) in fact solar thermal panels are best sited steeper than you state as approximately 37° In fact for a high solar fraction you need about 70 degree S facing. In our experience, informed people will take up to a 20% compromise on solar panel performance: this allows most E and W facing roofs. Here the document repeats dead myths again and is far too prescriptive in excluding these. Solar thermal panels are relatively low cost items. It only costs a little bit more to make panels bigger if they are sub-optimally positioned. Please will you state that E and W roofs offer 10-20% compromise only and that large steep S facing panels are the best for getting rid of fuel.

I hope this is interesting.

Regards, Barry