Sustainability Glossary

Buying a new build home today means coming across a whole new set of terms — many of them centred around sustainability, energy efficiency, and the environment. It can feel like a lot to take in. So we've put together this guide to help you understand the green language you're likely to encounter, from A to Z, so you always know what's going on:

 

A

Air Source Heat Pump (ASHP): The modern replacement for a gas boiler. A unit fitted outside your home extracts warmth from the outside air — even on cold days — to heat your home and hot water. It runs on electricity, produces no direct emissions, and is cheaper to run than a traditional boiler.

Air Tightness: A measure of how well sealed your home is against unwanted draughts. The more airtight it is, the less heat escapes — and the less you spend. All new builds are tested before completion and come with a ventilation system to keep the air fresh.

 

B

Battery Storage: A home battery — usually wall-mounted in a utility room or garage — that stores surplus electricity from your solar panels during the day, ready to use in the evening or on overcast days.

Biodiversity Net Gain (BNG): A legal requirement, introduced in 2024, that means new developments must leave nature measurably better off than before building began. You’ll see this in practice through wildflower areas, ponds, hedgerows, and bird and bat boxes built into the development.
 

C

Carbon Neutral: When the carbon a home produces is balanced out — either by generating clean energy on-site or by offsetting emissions elsewhere. Net impact on the climate: zero.

 

E

Ecology Corridor: A connected strip of green space — hedgerows, trees, long grass, ponds — that allows wildlife to move safely through a development. You’ll often spot these as the wilder, less manicured edges of a new build site.

EPC Rating: Your home’s energy-efficiency score, rated A (best) to G (worst). It gives you a guide to expected running costs. Most new builds achieve a B; those with solar panels and a heat pump often reach an A. Some lenders also offer better mortgage rates for A- and B-rated homes.

EV Charging Pre-Wire: The cabling needed for a home electric vehicle charger is already in place — you simply add the charger unit when you’re ready. It has been a legal requirement on most new builds since 2022.

 

F

Fabric First: A design approach that prioritises the performance of the building itself — walls, roof, floors, windows — before adding technology. Get the insulation and sealing right, and everything else becomes more effective.

Future Homes Standard: New rules coming into force in 2025 requiring all new homes to be built without gas boilers and to produce around 75% less carbon than homes built a decade ago. Heat pumps will become the norm as a result.

 

G

Green Mortgage: A mortgage product where some lenders offer lower interest rates on homes rated EPC A or B, on the basis that an energy-efficient home costs less to run and carries lower financial risk.

 

H

Heat Recovery Ventilation (MVHR): Because new builds are so well sealed, they need a controlled way to stay fresh. MVHR quietly replaces stale indoor air with fresh outside air, capturing most of the warmth from the outgoing air, so very little heat is wasted.

 

I

Insulation: Materials packed into walls, floors, and roofs that stop heat from escaping. New builds use significantly more and better insulation than older homes — one of the main reasons they cost less to heat and stay cooler in summer too.

 

L

LED Lighting: Fitted as standard in most new homes. LED bulbs use up to 80% less electricity than old-style bulbs and last years longer — a small detail that adds up over time.

 

N

Net Zero: When a home, development, or country produces no more greenhouse gas than it removes or offsets. The UK has a legal target to reach net zero by 2050, and new build homes are a key part of getting there.

Native Planting: Landscaping that uses plants indigenous to the local area — hawthorn, ox-eye daisy, dog rose, and similar species. They support local wildlife, attract pollinators, and need far less maintenance than imported ornamental species.

 

R

Running Costs: What it actually costs day to day to heat, power, and run your home. New builds with heat pumps and solar panels typically cost significantly less to run than older properties — often by several hundred pounds a year.

 

S

SAP Rating: The government’s method for calculating a new home’s energy efficiency. It produces a score that becomes your EPC band. You won’t usually see the number itself — just the A–G rating it generates.

Smart Export Guarantee (SEG): A government scheme that pays you for surplus electricity your solar panels export to the grid. Rates vary by supplier, so it’s worth finding a competitive tariff to make the most of what your panels generate.

SuDS (Sustainable Drainage Systems): Instead of rainwater rushing straight into drains, SuDS slow it down and let it soak into the ground naturally — through ponds, permeable paving, and shallow grassed channels. This reduces flood risk and often creates attractive green spaces within the development.

Solar PV Panels: Panels on the roof that convert daylight — not just direct sunshine — into electricity. Surplus can be sold back to the grid via the Smart Export Guarantee. Paired with a battery, they can meaningfully reduce your electricity bills year-round.

 

T

Thermal Bridging: A weak spot in a building’s structure — around a window frame or where a wall meets the floor — where heat escapes more easily than elsewhere. Good new build design minimises these using careful detailing and quality materials.

Triple Glazing: Windows with three panes of glass and two insulating gaps between them. They are better at retaining heat, reducing external noise, and limiting condensation than standard double glazing — and are increasingly common in new builds.

 

U

U-Value: A number that measures how much heat passes through a wall, window, roof, or floor. The lower the number, the better the insulation. Building regulations set maximum U-values for every element of a new build home.

Underfloor Heating (UFH): Pipes beneath the floor circulate warm water to heat the room from the ground up. It’s efficient at lower temperatures (which suits heat pumps well), spreads heat evenly, and frees up wall space with no radiators in sight.

 

Z

Zero Bills Home: A home built to such a high standard — with solar panels, a heat pump, battery storage, and excellent insulation — that the energy it generates covers what it uses. Some developers now guarantee zero energy bills for a set period after you move in.

Zero Carbon Ready: A home that isn’t yet producing zero carbon but is built so that achieving it requires no major work — because the gas boiler has already been replaced with a heat pump, solar panels are on the roof, and the building fabric is already performing well.

 

These are just some of the sustainability terms you might come across when exploring new build homes. If anything isn’t clear, our new homes team will be happy to talk you through it.