Jenny Smith-Andrews, Head of Marketing at aircrete manufacturer H+H, outlines the arguments for a building method that focuses on the long term.
The arguments around what constitutes sustainable building practice continue to shift focus. Back in 2007 the emphasis was on zero carbon in use for new homes. In 2022 much more attention is being placed on embodied carbon and the race is on for manufactures to decarbonise their businesses.
Both objectives are hugely important, of course, and H+H has demonstrated its ability to deliver on the first and now has a robust plan to deliver on the second. However, we would argue that there is an important third: the need to consider the long term.
It has always seemed strange to me that there is so little attention paid to how long a building should be expected to last. Most guidelines seem to anticipate a sixty year design life but surely this is insufficient?
In the UK we demolish about 9,000 homes per year. If we continue to replace the current housing stock at this speed, we would need every house built today to last not sixty years but several hundred.
This is not new information, but in this context it is odd that lightweight housebuilding systems are encouraged, based on their ability to meet speed of build and energy efficiency standards, with no apparent focus on longevity.
The crunch may come with the financial model. With house prices in 2021 averaging £198,000, mortgage finance is essential for most first-time buyers, and the length of available mortgage terms is rising.
Mortgage terms and housing durability
The English Housing Survey finds that 45% of first-time buyers in 2018-2019 had a mortgage of 30 years or longer and 40-year mortgages are becoming increasingly common. 2021 saw one company launching a 40-year fixed term mortgage.
What this essentially means is that to be attractive to buyers your home needs to be pretty sure to have a service life comfortably longer than a normal mortgage term.
Not surprisingly, H+H has always argued that masonry homes, designed to last for one hundred plus years, are the best long-term option in terms of financial security. We would also argue that the most sustainable homes are surely those which last a very, very long time.
Meeting the immediate
Right now, with the pressure to increase the volume at which we build new homes, the priority for builders is to ensure that familiar building methods can meet current building standards.
The latest collaborative project to involve H+H aircrete is Project 80, a research project designed to demonstrate how masonry building methods will meet the Future Homes standard, requiring a reduction of 75% – 80% over current building regulations.
Sustainable building – a holistic view
The arguments around what constitutes sustainable building will continue and the wisest course is surely not to focus on one performance aspect in isolation but to consider the bigger picture and take a holistic view.
For H+H this means building energy efficient homes whose creation involves the minimum possible immediate environmental impact and which will continue to provide a resilient, dependable asset for generations.
To find out more about aircrete from H+H, visit our website at www.hhcelcon.co.uk