10 April 2026
How Do Energy Efficient Homes Work?
Energy use is often an under-the-radar aspect when thinking about the next move.
A well-designed, energy efficient home is built to maintain a consistent, comfortable temperature throughout the year, using less energy to do so. That means spaces that feel warmer in winter, cooler in summer, and more stable day to day, without relying heavily on heating or cooling systems.
For many buyers, this shift has brought energy performance into sharper focus. How well a home works behind the scenes is as important as how it looks or where it is located.
It also helps explain why the difference between new build homes and older properties is becoming more relevant. Beyond layout and location, the way a home is built (and how efficiently it uses energy) can have a meaningful impact on everyday comfort and long-term costs. In this piece we will explore exactly how energy efficient homes are crafted, and how we’re leading the way with modernised new builds.
The Gap Between New and Old
One of the main reasons energy efficient homes perform differently is that they are built to modern standards from the beginning, rather than updated in stages over time. In newer homes, insulation, glazing, airtightness and heating systems are designed to work together as part of a single specification. In many older homes, those elements have evolved gradually through retrofitting, which can mean more variation in overall performance.
That difference shows up clearly in national data*. The Office for National Statistics reports that homes built after 2012 have a higher median EPC score than homes built before 2012, while official EPC statistics show that new dwellings in England are much more likely to achieve stronger ratings than existing stock. For buyers, this helps explain why the energy efficiency conversation is often as much about construction quality as it is about technology.
In other words, the gap between new and old is not just theoretical. It reflects the fact that modern homes are built around current expectations for energy use and carbon performance, giving homeowners the benefit of those improvements from the day they move in.
Insulation: Where Most of the Work Happens
Heat loss is the central problem in an inefficient home, and insulation is where the most meaningful gains are made. Older properties lose heat through their walls, floors, roofs and windows: through gaps that were never designed to be closed, or materials that predated modern standards by decades.
New builds approach this differently from the ground up. Cavity walls are fully filled at the point of construction, not retrofitted years later into a structure where the insulation was never meant to fit. Loft insulation is installed as standard and meets current building regulations rather than whatever was considered adequate in 1975. The floor is insulated before it is laid. New builds use full-fill cavity wall insulation or external wall insulation systems - a different proposition entirely from the patchy retrofitting that most older properties have undergone over the years.
The result is a home that heats up faster, holds heat longer, and requires less energy to maintain a comfortable temperature - translating to differences that show up directly on the energy bill every month.
Windows, Ventilation and the Details That Add Up
Double glazing has been standard in new builds for years, but the specification has moved on considerably from the double glazing of the 1990s. Modern glazing units use higher-performance glass, better frame seals, and trickle vents that allow background ventilation without the heat loss that comes from opening windows. In a well-insulated home, getting ventilation right matters: without it, moisture builds up and air quality suffers, which is why the two go together in any properly designed energy efficient home.
LED lighting across the home is now standard rather than optional. LED bulbs use around 90% less energy than a conventional bulb to produce the same level of illumination, which sounds like a small detail - until you multiply it across every room and every hour of use over a year.
Our new build flats and houses come with a premium specification of appliances as standard: the kind of considered selection that, running constantly in the background, compounds across months and years in a way that a cheaper specification does not.
Heating Systems in Modern New Builds
The way homes are heated has evolved significantly in recent years, with a growing focus on efficiency and lower-carbon technologies.
Gas central heating is still widely used, but modern condensing boilers are far more efficient than older systems, typically operating at over 90% efficiency under current standards. At the same time, building regulations have continued to tighten. The 2021 uplift to Part L of the Building Regulations* which applies to homes completed from 2022 onwards, requires improved energy performance across the whole property - including lower carbon emissions, better fabric efficiency and more effective heating controls.
Alongside this, alternative systems are becoming more common in new developments. Air source heat pumps, for example, extract heat from the outside air and use it to warm the home and hot water. When paired with a well-insulated building, they can deliver efficient, consistent heating with lower carbon emissions than traditional gas systems.
Solar panels are also increasingly included as part of new home specifications. By generating electricity on-site, they can help reduce reliance on grid energy and offset everyday usage: particularly as more households adopt electric vehicles or shift towards fully electric homes.
Together, these systems reflect a broader shift in how homes are designed: not only to meet current standards, but to anticipate how energy will be used in the years ahead.
*https://www.gov.uk/government/publications/conservation-of-fuel-and-power-approved-document-l
What This Means for Your Bills - and Your Mortgage
For buyers, the benefits of energy efficiency are more financially important than ever, and they tend to become more visible over time.
Research from the Home Builders Federation’s Watt a Save 2026 report found that new build homes can produce up to 73–74% fewer carbon emissions than older properties, largely due to improved construction standards and more efficient heating systems. That reduction reflects a home that requires less energy to run overall, which can translate into lower day-to-day costs.
Alongside design, location and specification, it plays a role in both the ongoing cost of living and the financial options available to buyers.
Energy Efficiency Across the Shanly Homes Portfolio
All Shanly homes are built to current building regulations, with the energy efficiency features described above built in as standard: not available as upgrades, but included as part of the full specification that comes with every home. That means the high-specification appliances, the glazing, the insulation and the efficient heating systems are part of what you are buying, without the need to negotiate or budget separately.
Whether it is a 1-bedroom apartment at River Walk in Tonbridge or a 3-bedroom home at De Havilland Place in Berkshire, the energy efficiency standard is consistent.
For anyone currently living in an older property and factoring in the cost of retrofitting (new windows, loft insulation, a boiler replacement, upgraded appliances) the comparative calculation is worth doing carefully. Energy efficient homes built to modern standards deliver those features as a starting point as opposed to a renovation project.
Browse our current developments today, or speak to a member of our helpful team for more information on energy efficiency and how we apply it across our homes.
