Green living

11 November, 2021

According to the Environment Agency, around 5.2 million properties in England are currently considered at risk of flooding, with remedial repairs typically costing between £20,000 and £45,000. All forms of flooding – from storm surge, river, rainwater, and rising groundwater – are set to increase in the coming years.

It’s not surprising. Many of the UK’s large towns and cities grew up around bodies of water, which facilitated trade and transport – not least London. The Thames Barrier remains a key defence against the growing threat of tidal surges flooding London, but more recently it has become pivotal in managing London’s rainfall by closing at low tide, keeping the sea out and creating space for the increasing volume of river water flowing into it.  

Flooding is one very visible environmental impact of increased rainfall but, in the south east, our hotter, drier summers are increasing the potential for subsidence – particularly on what is known as shrinkswell clay. Soil absorbs water in time of heavy rainfall, but shrinks as the water evaporates in hot weather. This can result in building movement, cracking and subsidence. Thousands of homes are affected every year by subsidence, losing as much as 20% of the property resale value.

Older homes built with shallower foundations can be particularly at risk, but that doesn’t mean that newer properties are immune. The dry summer of 2018 caused exceptional subsidence losses. In December A 2018, the ABI reported that the figures for July, August and September 2018 were the highest for subsidence claims since the record-breaking heatwaves of 2003 and 2006. Claims jumped from around 2,500 with a value of £14 million in the second quarter to around 10,000 with a value of £64 million in the third quarter.

Just as the environment affects our homes, our own behaviour impacts the environment. Half of the UK’s demand for power comes from homes, so managing this demand more efficiently could greatly help. Some mortgage lenders have started to reward homeowners who show a more responsible attitude to energy use. Green mortgages focus on energy efficiency and offer discounts to one degree or another for good behaviour. 

If you’ve recently rented or bought a house, you’ve probably come across Energy Performance Certificates (EPCs). Before the sale, purchase or rental period, an energy assessor takes measurements of the property, recording the building’s construction and energy systems. The resulting certificates feature the very recognisable brightly coloured bar charts that often adorn estate agents’ windows and tell prospective tenants and buyers how energy efficient their property is on a scale of A to G, with A being most efficient. Crucially, EPCs can also recommend changes, or retrofits, that would improve the home’s energy performance, which may include measures such as adding loft insulation or installing a more efficient boiler. 

Green mortgages are in their infancy. They may over time encourage homeowners to upgrade properties to maintain values, but for most homeowners the saving does not justify the expensive retrofit of new equipment for old. Those benefiting from ‘green mortgages’ for now have usually already had work done (such as triple glazing) or live in newer homes. Green mortgages are generally granted to those with a valid (often A or B rating) Energy Performance Certificate rating.

It has been estimated nearly two million homes in England and Wales could not be upgraded to an Energy Performance Certificate rating of C or above. Nevertheless, the government is aiming for as many homes as possible to reach a C rating by 2035 in England and Wales, with an earlier target of 2030 for private rented homes. An estimated 11 million homes in England and Wales do not have an EPC rating because they have not been sold or let since the certificates were introduced.  The fact remains that even if there was better coverage, EPCs are not a panacea.

The Environmental Audit Committee (EAC), which includes MPs of all parties, recently said EPCs do not support energy efficiency and low carbon heating measures. It recommended EPCs should be replaced by Building Renovation Passports. We may start with EPCs, but we may well not end there.

There is, meanwhile, an increasing amount of smart tech that will help us manage our consumption better. Apps are available that allow us to manage power remotely or turn off non-essential power automatically during peak times. These are relatively easy to install and allow us to manage current fossil fuel systems better.

Changing heating systems is far less easy. Homeowners may end up using a blend of solutions electrifying heating remedial work were issued and only 5,800 energy efficiency measures installed. Energy is a complex issue for housing and policy makers. Few politicians want to be honest with voters (also known as bill payers) about the small fortune they will need to fork out for a new hydrogen boiler in a decade’s time. But over and above the cost, saving energy can be fraught with laws of unintended consequences.

Not so long ago the government exhorted homeowners to insulate their homes, but cavity walls were built as a barrier against penetrating dampness. When retrofit cavity wall insulation is installed into a property that is located or built in a way that means it should not have the cavities fully filled (or if the work is undertaken incorrectly), the first and most obvious sign of a problem is often internal dampness. The insulation successfully stops both warm air and moisture escaping, meaning humidity levels rise and mould is almost inevitable.

In extreme cases, cavity walls have been fully filled in timber frame houses and, as the damp cavity wall filling material comes into contact with the wood frame, rot sets in.

The government will have to tread carefully when progressing any changes relating to the energy efficiency of properties – such as requiring homeowners to upgrade properties with expensive remediation work. It could create a negative effect on property values with low-rated homes becoming blighted by their ratings.

A key issue for many mortgage lenders is the prospect of green mortgages creating another generation of mortgage prisoners – people who cannot afford to upgrade and obtain the cheaper finance. Understanding not just what a property is made of, but what improvements may have affected or decreased its value in energy efficiency (not to mention issues of older and newer materials under increasing heat stress) is a huge undertaking. Our national property stock is ageing and there is no one size fits all solution for our homes because of geographic, build type, or build-technology considerations.

This means offering alternative solutions and developing an energy strategy that perhaps works higher up the supply chain and allows the integration of many power sources into the grid to be accessed flexibly by homeowners. Our homes will have to change to incorporate a range of new technologies to reduce their energy use, and to cut the energy needed to build them. Heating systems, insulation and water usage offer some easier ways of addressing energy efficiency. Homeowners that understand this are likely to fare better in maintaining their property’s value than those that do not.

Water is acknowledged by experts to generally be the enemy of buildings, but the fact remains that we need it for ourselves. How much we use and for what purpose is increasingly a matter of debate. A report by the National Infrastructure Commission (NIC) calculated that Britain would need to find an extra 4,000 million litres a day to cope with a drier climate and population growth by 2040.

The NIC continued that every household would have to save an extra 23 litres of water daily.  Our water usage has been changing for some time as usage and bills are being reduced by installing lowflow shower heads, fixing leaky pipes, and retrofitting toilets with low- or dualflush devices. But beyond sanctions on dishwashers, power showers and other devices, grey water (reemploying the water used from baths, showers, and hand basins) offers a huge saving opportunity – particularly for new build properties.

The systems remain, for now, relatively expensive to retrofit to older homes where the return on investment may be up-to and beyond ten years by some estimates. How these systems are installed, managed and maintained is crucial as water kept in tanks for re-use has to be cleaned and kept free of bacteria.