Responding to the great refurbishment challenge

Published:  05 May, 2011

CIBSE, refurbishment
A huge challenge, and no refurbishment industry — Rob Manning.

Meeting the UK’s long-term targets for reducing carbon emissions from buildings cannot be met simply by new buildings achieving zero or very low carbon emissions. The difficulty is that by 2050, the vast majority of the domestic and non-domestic building stock will have been built before even the 2010 Building Regulations came into effect.

More precise figures were presented by CIBSE president Rob Manning as he opened the recent CIBSE conference on ‘The great refurbishment challenge’.

He expects there to be 34 million homes in the UK in 2050, 25 million of which already exist and very many of which were built to standards much less than the 2010 Building Regulations.

Of the non-domestic stock, 60% of the floor space that will exist in 2050 had already been built by 2010.

Buildings are responsible for a large proportion of the UK’s carbon-dioxide emissions. Rob Manning referred to data from 2005 which showed domestic buildings to be responsible for 27% of the total CO2 emissions of 550 Mt, with commercial and public buildings contributing 13% and industrial buildings 5%. The sum total is 45%.

There is another important reason for reducing the energy consumption and carbon emissions of buildings — and that arises from the UK being a net importer of energy. The Government perspective is that lower energy demand requires less generating capacity to be built in the future and less dependency on imported fuel.

The contribution of building refurbishment to achieving all those objectives is all too apparent. Still surprising is the scale of the effort needed — one building a minute between now and 2050.

As Rob Manning points out, the scale of the challenge is huge, and there is as yet no established refurbishment industry — especially in the domestic sector. There is also a shortage of skills and knowhow.

In contrast, highlights Rob Manning, progress with the new building stock is ‘pretty good’. Building Regulations are being updated every three years, Display Energy Certificates are having an effect for public buildings, and the Code for Sustainable Homes is a force in the domestic sector.

CIBSE’s conference did much to increase awareness of the need for energy-efficient and low-carbon building refurbishment and also focused attention on effective refurbishment programmes. The conference also highlighted, however, how little the knowledge and experience acquired from new build is benefiting refurbishment and also how experience from refurbishment projects was not enhancing future projects. There is clearly a pressing need for credible evidence to demonstrate the energy efficiency of refurbishment in practice.

Summing up after the conference, Rob Manning said, ‘The message we were hearing was that the lack of really good case-study information is holding back the refurbishment drive. In order for clients to believe that the work can be done, we need to build a body of evidence from practical examples that make the economic and environmental case for refurbishment.’

The value of refurbishment for reducing energy demand was neatly put into perspective by David Fisk of Imperial College London when he indicated that the cost of electrical generating capacity is £2000 per kilowatt — a figure that was accompanied by the suggestion that ‘it is peanuts to reduce energy use’. Former CIBSE president Terry Wyatt was also prompted to ponder on how much the demand for energy could be reduced for an expenditure of £2000.

One of David Fisk’s concerns was benefiting from increasing experience of energy-efficient new build: ‘We are now putting up buildings that are very energy efficient compared with, for example, 1950s buildings. How do we get those wins into refurbishment?’

He also stated an R&D need for refurbishment, such as how to make solid-wall insulation ‘sexy’, but also how to do it properly. And as an example of how little feedback there is from refurbishment projects David Fisk pointed out that 20 000 heat pumps have been installed, but there is no feedback — so everything keeps being done first time.

A question about the role of Display Energy Certificates prompted David Fisk to suggest, ‘There is a need to keep DECs simple so that they can alert people to the performance of the building. If the chief executive has to walk past a G-rated DEC every day, something will be done. DECs are super because they encourage serious engineering dialogue with facilities managers. Getting DECs into refurbished buildings is a tremendous opportunity to do good engineering.’

And an example of good engineering came up almost immediately from George Adams, engineering director with SPIE Matthew Hall and vice-president of CIBSE, when he described a project carried out for JLT in London.

This company was wanting to move more people into an existing occupied building and perceived a need to increase the power supply to support that increased occupancy and higher IT demand. Upgrading the power supply would have cost £1.2 million and required phased shutdown.

When the services engineer looked at the problem, the recommendation was to upgrade the lighting to reduce its power consumption and make it available for IT equipment — at a cost of just £630 000. Disruption to the operation of the business was avoided and the working environment improved.

Upgrading the lighting reduced electricity consumption by 8%, of which 6% was re-used for increased occupancy. The final carbon saving was 2%, with the £500 000 capital saving being paid back in less than 15 years. But given such an engineering solution to the client requirement, how significant is the financial benefit?

The JLT refurbishment was in response to a particular need, but green refurbishment can bring valuable benefits, as evidenced by a project in Melbourne, Australia, described by George Adams.

Not only were energy savings of 50% achieved, but there were a host of business benefits. For example, one occupant of the building reported a 44% reduction in the average monthly cost of sick leave, while another reported an increase in billing ratio despite a 12% reduction in average hours worked. Symptoms of colds and flu were also reduced by up to 24%.

Getting large organisations to commit finance to refurbishment as opposed to other projects requires a good financial case to be presented, explained Kate McCormick, energy analyst with SPIE Matthew Hall. She stressed that role of the engineer is as the salesman of refurbishment to the financial controller and that they must be able to speak their language — using such terms as present value, discounting, equivalent annual costs, savings-to-investment ratio and whole-life cost.

While whole-life costing is a tool rather than a science, it enables options to be compared on a like for like basis. The division between capital costs of around 25% and operation and maintenance costs of 75% is widely appreciated, but what about the ‘green premium’ with a 2% investment yielding a 20% return.

CIBSE, refurbishment
A huge challenge, and no refurbishment industry — Rob Manning.

A detailed analysis of the costs associated with refurbishment projects by Simon Harris, director of cost consultancy with Cyril Sweett, suggested that a ‘market improvement’ for a range of office buildings of various styles and ages before the year 2002 would reduce energy consumption by 24 to 30%.

He then considered the energy-savings benefits of spending more money.

An additional £25 per square metre would achieve total energy savings ranging from 35 to 47%, increasing to 42 to 50% for an additional budget of £50 per square metre.

Further energy savings are harder to come by, with even an additional £150 per square metre achieving only 54 to 63% energy savings.

The reaction from the floor was that £25 to £50 per square metre additional investment is tiny compared with rental values and that the extra investment might enhance rental values.

Given a vacant office to improve, Simon Harris’s top six upgrades were, with, CO2 saving per square metre and payback, as follows.

• Upgrade heating pumps to variable speed; 0.57 kg; two years.

• Upgrade lamps in office luminaires to 10 W/m2; 2.57 kg; three years.

• Fan-coil units with DC motors; 7.94 kg; three years;

• Heat-recovery thermal wheel; 7.61 kg; eight years.

• 20 kW wind turbine; 6.01 kg; nine years.

• Upgrade boiler to 95% efficiency; 6.79 kg; 10 years.

District energy schemes based on combined heat and power, biomass, geothermal energy and energy from waste can play a useful role in reducing carbon emissions in areas with high densities of buildings. That was the message from Simon Woodward, CEO of Cofely District Energy and chairman of the UK District Energy Association (UKDEA). He said, ‘District energy networks are agnostic — they can accept heat from a variety of sources.’

There are plenty of district-energy schemes in the UK operated by UKDEA members. Key facts are over 100 MW of low-carbon generation plant supported by over 500 MW of conventional back-up boiler plant and delivering over 500 GWh of heat a year. The energy networks they serve have a combined extent of over 200 km. Simon Woodward’s message is that you don’t need to go overseas to see good practice; it is right here in the UK.

To concerns about heat losses and reliability, he points out that heat losses are 1 K/km and that ‘district-heating pipework doesn’t fail these days; it is good for 50 years’. As to reliability, 99.98% has been measured for the Southampton geothermal system over 25 years.

The Birmingham district energy scheme provides some good examples of building refurbishment combined with district heating. Simon Woodward described three projects.

One was Birmingham Town Hall, a listed building that has been extensively refurbished but with very limited options for low-carbon generation. A thermal link was made to the district energy scheme to supply all heat with a low carbon burden and low cost. The overall result has been an improvement in the DEC from E to C.

Likewise, two residential tower blocks with life-expired electric heating were connected to the network and have seen CO2 emissions reduced by over 347 t a year.

Another project is the extensive refurbishment of a 25 000 m2 1960s office building that was undertake while it remained occupied. Multiple gas-fired boilers were replaced with a district-heating connection, and the DEC improved from a poor G to a good E. Having made a connection to this building, it was easy to make a link to new student accommodation adjacent and expand the district heating network further.

CIBSE’s conference amply demonstrated awareness of and the importance of building refurbishment in achieving carbon-emission targets and improving the security of energy supply. There is plenty of awareness of what could be done, but, as yet, not enough understanding of the most effective measures. The call for a body of evidence from practical examples needs to be heeded.

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