Net-zero rules set to send cost of new homes and extensions

New building regulations aimed at improving energy efficiency are set to increase the price of new homes, as well as those of extensions and loft conversions on existing ones.

The rules, which came into effect on Wednesday in England, are part of government plans to reduce the UK’s carbon emissions to net zero by 2050. They set new standards for ventilation, energy efficiency and heating, and state that new residential buildings must have charging points for electric vehicles.

The moves are the most significant change to building regulations in years, and industry experts say they will inevitably lead to higher prices at a time when a shortage of materials and high labour costs is already driving up bills.

Brian Berry, chief executive of the Federation of Master Builders, a trade group for small and medium-sized builders, says the measures will require new materials, testing methods, products and systems to be installed. “All this comes at an increased cost during a time when prices are already sky high. Inevitably, consumers will have to pay more,” he says.

Gareth Belsham, of surveyors Naismiths, says people who are upgrading, or extending their home, will be directly affected.

“The biggest changes relate to heating and insulation,” he says. “There are new rules concerning the amount of glazing used in extensions, and any new windows or doors must be highly insulated.”

The changes could mean an extra £3,000 added to the bill of an average home extension, according to Jonathan Rolande of the National Association of Property Buyers, a group of professionals aimed at raising construction standards.

Homeowners extending may see the amount of space they have decrease, as walls will have to be thicker in order to comply with requirements for better insulation.

Andrew Mellor, of PRP architects, says external walls will need to be about 7cm thicker than previously.

Windows and doors will have to adhere to higher standards, while there are new limits on the amount of glazing you can have to reduce unwanted heat from the sun.

Thomas Goodman, of MyJobQuote, a site which sources quotes, says this will bring in new restrictions for extensions.

“Glazing on windows, doors and rooflights must cover no more than 25% of the floor area to prevent heat loss, ” he says.

As properties become more airtight, there are also measures to ensure proper airflow, such as having small openings (trickle vents) on windows that allow ventilation when a window is closed.

For people extending their homes, they may be required to install a new, or replacement, heating system depending on the size of the build, says Belsham. These will have to use lower temperature water to deliver the same heat, which will require increased insulation of pipes.

“We’ll see more insulation, better lighting design and restrictions on the amount of glass used in some areas. But with more thermal-efficient homes can come the risk of overheating due to solar gain, and so ventilation is also covered,” says Rolande. “As a result, double-glazed windows will require trickle vents to let heat escape and also to provide fresh air for health reasons and, of course, to reduce the risk of condensation build up in an ever-more airtight property.”

As the rules came into effect last Wednesday, property developers were rushing to file plans just before the deadline, according to Belsham. Any plans submitted before that date are considered to be under the previous rules, and can go ahead as long as work starts before 15 June next year.

Builders which have costed projects, but have not filed the paperwork, may need to go back and submit fresh estimates, says Marcus Jefford of Build Aviator, which prices projects.

As the changes are aimed to make homes more energy efficient, they will eventually drive down heating bills. But in the short-term homeowners are likely to face higher costs for work.

Materials prices are already up 25% in the last two years, according to figures from the Construction Products Association.

How much overall prices will increase as a result of the rule changes is not clear. “While admirable in their intentions, they will add to the cost of housebuilding at a time when many already feel that they are priced out of homeownership,” says Rolande. “An average extension will probably see around £3,000 additional cost thanks to the new regs.”

John Kelly, a construction lawyer at Freeths law firm, believes prices will eventually come down. But not in the immediate future. “As the marketplace adapts to the new requirements, and the technologies that support them, the scaling up of these technologies will eventually bring costs down, but in the short term, we will all have to pay the price of the necessary transition,” he says.

However, the long-term effects of the changes will be more comfortable and energy-efficient homes, adds Mellor. “Homeowners will probably recoup that cost over time in energy bill savings. It will obviously be very volatile at the moment, but they will have that benefit over time.”

In the future, there will be increased competition between companies to supply insulation technology, says Belsham, which should result in lower prices.

Failing to follow building regulations could result in prosecution. Local authorities have the power to serve an enforcement notice forcing the owner to alter, or remove, the contravening work.

The measures are part of government plans to reduce carbon emissions as part of its bid to make the UK net zero by 2050. Last week’s rule changes apply to England. Scotland and Wales brought in similar changes recently.