Energy efficiency in historic buildings

Welcome to Energy efficiency in historic buildings: The Energy Efficiency Podcast, episode 3, the podcast that brings you a mix of energy efficiency news, products and tips all year round. We’re interested in profiling people and products involved in promoting energy efficiency habits, products and information, so please do get in touch if you have something to contribute.

This week: energy efficiency works to historic buildings, energy efficiency across the world and sustainability in the construction industry.

Net zero carbon emissions

Before we get on with our advertised features, this week Theresa May, outgoing British PM, has put into law what is seen as her legacy: a commitment that Britain will achieve net zero carbon emissions by 2050, which would make Britain the first major economy to enact such legislation. Small countries including Finland and Norway are aiming for earlier dates – 2035 and 2030 respectively. What does May’s move mean for the UK, how likely is it to be  achieved, and how is it likely to be achieved?

Although the move is broadly welcomed, Greenpeace was critical of the carbon credits element of the proposed legislation, which is in the form of an amendment to the Climate Change Act. As a statutory instrument it doesn’t go to a vote of MPs. This is significant because among other criticisms the chancellor Philip Hammond claimed the move would cost £1tn and would lead to spending cuts.

CCC

The 2050 date was the recommendation of the official UK Committee on Climate Change (CCC), but May’s proposed use of carbon credits goes directly against the advice of CCC chairman John Gummer. What are carbon credits? According to Investopedia:

“A carbon credit is fundamentally a permit—issued by a government or other regulatory body—that allows its holder to burn a specified amount of hydrocarbon fuel over a specified period. Each carbon credit is valued against one ton of hydrocarbon fuel. Companies or nations are allotted a certain number of credits and may trade them to help balance total worldwide emissions. “Since carbon dioxide is the principal greenhouse gas,” the United Nations notes, “people speak simply of trading in carbon.”

Carbon trading

It’s felt by many that carbon trading places pressure on developing nations. Doug Parr, chief scientist for Greenpeace UK, describes carbon offsetting as “shifting the burden to developing countries” and goes on to describe it as having a history of failure.

Just as the renewables industry we talking about in episode 1, which will be a major plank of net zero, achieving this target requires the correct investment and infrastructure. An article in the Independent suggests that meeting the target will mean

“an end to heating of homes with traditional gas boilers, more green electricity, and a switch from petrol and diesel cars to electric vehicles, walking and cycling.”

With the exception of mothballing gas boilers, none of these are revolutionary moves but none the less May has firmly parked responsibility for the detail as something to be dealt with by future governments, criticised by some as lack of a detailed plan. Whatever your politics, it seems reasonable to allow for accommodating developments in technology. We struggle to predict economic conditions five years ahead at the moment, so to put together a detailed plan to achieve a target that is 30 years away would seem a grand waste of time for all involved. It’s expected the move will receive broad parliamentary support, so we’ll report back on what happened next.

Energy efficiency in historic buildings

Pre-1919 houses

Energy efficiency in historic buildings is far from straightforward. Historic buildings, from medieval castles to interwar housing blocks, have a tendency to look pretty (yes, even interwar housing blocks have their fans) but be hard work to live in. They can be

Passivhaus

Welcome to Passivhaus: The Energy Efficiency Podcast, episode 2, the podcast that brings you a mix of energy efficiency news, products and tips all year round. We’re interested in profiling people and products involved in promoting energy efficiency habits, products and information, so please do get in touch if you have something to contribute.

Passivhaus

A passivhaus in Darmstadt

If you’re interested in energy efficiency chances are you’ve heard of passivhaus. In very simple terms passivhaus is an airtightness standard achieved through high-performance windows, doors and other danger zones together with very high levels of insulation and efficient heating systems. The certification can be applied to whole buildings, specific components such as windows, and the architects and tradespeople involved in the design and build. Rigorous testing is carried out before anything or anyone involved can be designated to have met the required standard.

As a guide, a passivhaus building will have excellent insulation, low-energy services and require very low levels of energy to keep at a comfortable temperature. In the UK building regulations typically require a level of insulation and energy efficiency far lower than passivhaus, and within that standards vary across England, Scotland and Wales, and differ between domestic and non-domestic buildings.

Exeter

However some organisations in the UK are building to passivhaus standards. They clearly recognise the benefits of keeping buildings at a comfortable draught-free temperature at a low energy cost. Exeter City Council is one. For the last 10 years all new council buildings in Exter, both residential and commercial, are very low energy (meeting passivhaus standard), healthy (meeting the German Building Biology principles), climate ready and set within a sustainable landscape. The Association for Public Service Excellence has this to say:

“These buildings are healthy for residents and occupants, comfortable regardless of the weather and extremely cost effective to run (thereby helping to eradicate fuel poverty). From a Council perspective we have reduced operating and lifecycle building costs, happier and healthier tenants with reduced rent arrears and anti-social behaviour and exemplar buildings that are performing way beyond comparable building regulation compliant assets.”

But what do you have to do to create buildings operating to such high energy efficiency standards? It comes down to reducing heat loss, maximising the effect of passive sources of heating such as sun, body warmth and extracted or emitted heat from household appliances, and making up any shortfall with low energy heating systems. The Passivhaus Institute describes it as

“A Passivhaus is a building in which thermal comfort can be achieved solely by post-heating or post-cooling the fresh air flow required for a good indoor air quality, without the need for additional recirculation of air.”

High standards

This can be a very complex process requiring expensive high-performance elements such as triple-glazed windows and a mechanical ventilation system with efficient heat recovery; extremely detailed planning; and specialist builders and fitters.

It’s not feasible in many cases of renovating an existing property, in which case EnerPHit can be a more appropriate standard to aspire to. This is a slightly less exacting standard designed for renovations, particularly where the architecture of the building needs to be conserved. Improving the energy efficiency of historic buildings without causing more problems than you solve is something we will look at in a future episode.

EnerPHit

A Victorian house

The UK has one of the highest proportions of pre-WWII domestic buildings in Europe. Unsurprisingly old and inefficient buildings have been identified as one of the biggest contributors to energy wastage in the EU.

The EU has identified energy efficiency as one of the pillars of its

UK Renewables

Welcome to UK Renewables: The Energy Efficiency Podcast, episode 1, the podcast that brings you a mix of energy efficiency news, products and tips all year round. We’re interested in profiling people and products involved in promoting energy efficiency habits, products and information, so please do get in touch if you have something to contribute.

UK Renewables

Wind farm

At the end of May the UK press was widely trumpeting the fact that Britain (without Northern Ireland) had managed to power itself for two weeks without burning any coal. Since April the periods without burning any coal had lengthened, from 90 hours, to a week, to two weeks. At the same time, on one day a quarter of Britain’s needs was met by UK renewables in the form of solar energy alone.

Renewable UK, the renewable energy trade association, states that half of UK renewables comes from wind power, something in which the UK has been a pioneer and which continues to grow.

Other fuels

It’s important to bear in mind that not all non-coal power comes from UK renewables. Nuclear and gas play a part. It’s also the case that some of Britain’s coal-fired power stations were always on their way out. They are outdated and/or fail to meet European regulations on acid rain.

The government has done something to support solar and wind installation through subsidies, but it’s carbon pricing that has really seen gas become more attractive than coal as it emits less carbon. This merely swaps one fossil fuel for another. Switching from a position of using 100% coal for power production to 100% UK renewables was always going to be a circuitous journey.

Julian Leslie of National Grid Electricity System Operator – NGESO – expects these runs of non-coal power to become the new normal as UK renewables source infrastructure increases. Julian Leslie believes that by 2025 we will be able to fully operate Great Britain’s electricity system with zero carbon. This requires a significant boost to renewable energy production. With seven of the UK’s eight nuclear power plants stopping energy production in the next 11 years and only one new plant due into operation, emissions could begin to rise without sufficient renewable energy ready to fill the gap.

This is a business operation as much as an engineering challenge. Investment is essential. Third-party services must be identified and secured. If your company is in the offshore wind industry, you might be interested in the Global Offshore Wind conference in Manchester on the 19th-20th June. You can find out more about that at events.renewableuk.com

Energy efficient appliances

The bigger the fridge the more power it uses

Energy is precious and usually expensive. You don’t want to waste the energy you pay for. There are all sorts of ways to save energy in the home and we’ll be talking about as many as we can in coming episodes, but one that we all face from time to time is replacing an energy-hungry appliance such as a fridge or a washing machine.

According to choose.co.uk the UK spends almost £3.5bn on electricity each year just to keep our clothes clean, wash our dishes and freeze our food. The worst offenders include electric immersion heaters, fires and showers, the dishwasher and it won’t surprise you to hear, the tumble drier.

These items and the other household items we rely on such as boilers and freezers take a great deal of water and energy to produce in the first place, so consider carefully just what it is you’re wanting to achieve – is it lower household bills through running more energy efficient appliances, or reducing your overall consumption of raw materials by using an appliance until it’s beyond repair? The energy efficiency of household items has improved in leaps and bounds in the last few years so there are great energy savings to be made. If the time has finally come to replace an item, what do you look out for, and w