Rural Homes Set To Remain Disadvantaged After Heating Decarbonisation

Opinion: Home heating accounts for 14% of the UK’s carbon emissions — so natural gas has to be phased out. Hydrogen is a possible future replacement for properties connected to the gas grid, but rural properties currently relying on oil or liquefied petroleum gas are likely to remain heating Cinderellas.

Replacing 22.5 million gas central heating boilers across the UK well before 2050, as we need to do to meet current climate change commitments, has a huge price tag. Renewables-powered heating systems are currently much more expensive than boilers heated by natural gas (well, not so natural, but it sounded such a clean product). The Committee on Climate Change has forecast a switch-over cost of £28 billion a year by 2050.

Living off the gas grid means that here in rural Wales we could not have joined the 82% of UK households with mains gas central heating (although the Energy Performance Certificate for an off-grid house that I know of states that there is mains gas central heating, a mistaken or deliberately untrue ‘fact’ – it’s important to check those certificates!).

By early 2019 it was time to replace an ancient oil boiler, which sounded like an aeroplane taking off into a rumbling thunderstorm. As well as the need to slash fossil fuel use, there was the immediate practical problem that no one’s insurance – not the household policy, not the delivery firm’s policy – would cover taking the hose from the tanker through the house to the oil tank behind.

The garden was not large enough for a ground source heat pump system with pipes in horizontal trenches (you need at least half an acre, I am told) and even more to the point, was inaccessible to the equipment needed to excavate trenches, or to dig a borehole for a vertical installation. Ground source heat pump installations are super-expensive, from above £10,000 to over £20,000 for the pump and installation, plus thousands more for the groundworks. They qualify for the Westminster Government’s Renewable Heat Incentive, which in theory could pay the majority of costs over seven years, but the homeowner or landlord has to find the money upfront first.

In the end we settled on an air source heat pump. This is costing between £8,000 and £9,000 including new, larger radiators, and for which we might receive the Renewable Heat Incentive (if we can tick all the eligibility boxes). The garden is wide enough, fortunately, because in Wales the pump units have to be at least three metres from boundaries to qualify as permitted development (in England, it’s only one metre).

Bearing these costs in mind, it is unsettling to know that the Renewable Heat Incentive closes to new applicants on April 1^st 2021, and no replacement scheme has been announced. The current scheme covers ground source heat pumps, air source heat pumps, biomass boilers and biomass pellet stoves, and flat plate and evacuated tube solar thermal panels.

Maybe the government is hoping that hydrogen fuel cell boilers will soon become available, and at lower cost than heat pumps. Manufacturers are developing such boilers: in June 2019, Dutch group BDR Thermea installed what it claimed as the world’s first hydrogen-powered domestic boiler in a trial project in Rozenburg, the Netherlands. In theory, hydrogen boilers could use much of the same infrastructure as gas boilers, and households would not have to change all their pipework and radiators. The Government’s decision to ban gas boilers in new homes from 2025 should, at the very least, boost interest in hydrogen systems.

But now that the UK has left the EU, it will be fascinating to see if British firms can compete with European enterprises to perfect hydrogen home heating.

Even if they can, a hydrogen system taking over gas infrastructure will not reach the rural areas where there is no gas grid. Hard-to-heat rural homes would be disadvantaged yet again.

PDR

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Opinion: For the Lack of 2.64 Inches of Insulation, £8,000 Evaporates

The prospect of receiving Renewable Heat Incentive payments from the UK Government, estimated at £8,000 over seven years, was enticing. It hasn’t worked out, though.

I inherited a Victorian terraced house, which is now let to a local couple. An ancient oil boiler powered the central heating, the oil supply coming from a tank in the back garden.  To fill the tank, the oil tanker driver had to lug the hose through the house, an action not covered by my buildings insurance or the oil delivery company’s liability cover.  It was time to change the heating for a more eco-friendly system.

The walls are stone

Main gas is not available, and of course is also a fossil fuel. The same applies to coal and to LPG, liquefied petroleum gas.  Wood or wood pellets would be cumbersome for an elderly occupant, and also need a big storage space. An electric boiler would cost the occupants a lot to run, typically between 40% and 50% more than a gas boiler. The garden is too small for a ground source heat pump. In the end I opted for an air source heat pump, an 8.5kW Vaillant Arotherm. All the existing radiators and pipework had to go, and the system cost £8,725, about twice as much as a replacement oil boiler would have done.

“But you will qualify for the Renewable Heat Incentive,” I was told.

Actually, no.

Computer says no

It’s because of the ‘Standard Assessment Procedure’ software used by energy performance assessors. At least, that’s what I understand. You get different answers from different people in the information chain.

The method for creating an Energy Performance Certificate (EPC) is ‘standard’, in that it is a tick-box exercise using assumptions about construction based on the regulations (if any) applying when properties were built, unless there is validated evidence to the contrary.

The rules for the Renewable Heat Incentive (RHI) state that if the property’s EPC requires cavity wall insulation or more loft insulation, this must be done before any RHI will be approved. The EPC for the old house in question did not insist on cavity wall insulation, because it is built of stone “and so requires further investigation to establish whether these walls are of cavity construction and to determine which type of cavity wall insulation is best suited”. Yet modern assumptions about the defects of traditional materials may not be correct. The Society for the Protection of Ancient Buildings (SPAB) points out in its 2014 briefing ‘Energy Efficiency in Old Buildings’ that

“….standard U-value calculations, used across the construction industry to measure the rate of heat loss through materials, underestimate the thermal performance of traditional walls. In some instances, it now appears that actual heat loss through vernacular materials such as wattle and daub, cob, limestone, slate and granite can be up to three times less than previously calculated. These findings – and those from Historic Scotland and English Heritage which have looked at sandstone and brick construction – are significant. They tell us that we need to think very carefully before rushing in because they suggest that conventional industry practices are struggling to accurately represent the thermal performance of traditionally built walls. Ultimately, this could have negative consequences for historic buildings as calculated theoretical U-values, suggesting a poorer performance, may lead owners and professionals to adopt disproportionate energy saving interventions that may not only be unnecessary, but also invasive and potentially harmful to the fabric of a building and its occupants. U-values are not the complete story.” (p6, in the section ‘Understanding old buildings, by Jonathan Garlick)

The EPC for the Victorian house does stipulate increasing the loft insulation to 270mm, 10.63 inches. The problem here is the depth of the joists supporting the floor of the loft. They allow 8 inches (203mm) of insulation under the floor, 67mm (2.64 inches) less than amount required.

The loft, which has a window and a pull-down access ladder, is used for storage, so it did not seem a great idea to remove the floor to add 2.64 inches of insulation, or indeed to put 2.64 inches above the floor. A supportive adviser on the RHI helpline suggested contacting a chartered surveyor, which I did. He proposed insulating between the rafters. Before going ahead, I asked an EPC assessor if insulation between the rafters would be added to insulation between the joists, to give the required total.

The boarded loft 

The assessor asked the technical department of their EPC certification body, and returned with the answer “No. If there is insulation between the joists, only this can be counted, and insulation between the rafters will be ignored.” This is what the software mandates, apparently.

At first this seemed counter to common sense, but then I wondered if putting a rigid insulation board between the rafters would help or hinder the longevity of the building. Condensation and moisture retention could damage the timbers and create an unhealthy atmosphere. The SPAB briefing says:

“Achieving a coherent insulation strategy that actively deals with moisture is relatively difficult in many older buildings, particularly around openings and junctions and in complex structures. If it is too difficult to achieve, it is sometimes better (as far as moisture risks are concerned) to have no insulation and just ensure that the heating and ventilation systems are good.” (p.20, in the section ‘Ventilation and health’ by Neil May)

If you have a listed building, or one in a conservation area, you can claim an exemption from the insulation requirements. You can also claim exemption if a protected species, such as bats, lives in the property, or if there are adverse environmental conditions, verified by a chartered surveyor. If a chartered surveyor says the property is not structurally suitable for insulation, that might also count. Might.

Age discrimination against heritage homes

The CLA, Country Land and Business Association, calls the EPC requirements “age discrimination against our heritage homes”. The CLA says:

“Some of the energy efficiency improvements being recommended on the EPC are unsuited to properties built using traditional construction techniques. These buildings were designed to be ‘breathable’ and allow moisture to pass through the structure. The effect of modern insulation on these properties could be similar to wrapping fruit in impermeable plastic, the moisture cannot escape, moisture builds up and the contents start to rot. This is particularly worrying for listed buildings and those within conservation areas.” (press release from the CLA for ‘The Retro Fit-Up’, March 2017)

It seems that although insulation exemptions can be claimed for listed buildings, they may not be exempt from the requirement to have an EPC when sold or rented, unless it can be proven (probably by a local authority conservation officer) that work to improve energy efficiency would damage their character.

It would be better, but more expensive given that an EPC can cost under £100, to create a bespoke energy improvement plan for every building, taking the impacts on structure and character fully into account. That would require people to spend heavily, probably £500 and over, to obtain what is currently a compulsory document, and would surely be criticised as an unfair burden unless it had a long validity, say 10 to 20 years.

As for the standardised EPC, I rather wish it will go the way of the late and little-lamented Home Information Packs – into oblivion.

PDR