What makes a building eco-friendly?

Awareness of our impact on the environment is increasing every year. More and more of us are paying attention to our ecological footprint, perhaps as part of an accreditation programme or an environmental commitment. More and more schools are taking part in Eco-schools, for example.

This awareness is more important in the construction industry than almost anywhere else, because buildings are responsible for such a big share of carbon emissions – 40% of Britain’s emissions come from the built environment.

Taking responsibility for this has always been part of our philosophy, and we’re committed to designing eco-friendly buildings. But what does that mean? What are we talking about when we talk about sustainable construction?

If you’ve looked into this at all, you may have come across a variety of different standards. PassivHaus, for example. Or BREEAM, or LEED standards in the US. These are all slightly different and it can get rather confusing and technical. At the heart of it are a handful of considerations. Here are five of them, with some of the ways that we address them at Green Modular.


materials matter. They can contribute directly to environmental problems, such as deforestation. They also have ‘embedded carbon’ – the amount of greenhouse gas emissions needed to make them. Cement is particularly carbon intensive, for example. Sustainably harvested wood, on the other hand, locks up the carbon that the tree absorbed while it grew, and is carbon negative.

All materials also have a real world performance, and then a time when they reach the end of their lives and have to be replaced. Choosing the right materials is crucial. At Green Modular, we design lightweight buildings that don’t need dug foundations, which means we don’t need concrete. We use recycled materials where possible, and wood from (FSC certified) sustainably managed forests.


In temperate countries like Britain, heating is the main source of energy use and therefore of carbon emissions. The amount of heating that a building needs is basically locked in at the design stage, so designers need to give careful consideration to how their buildings manage temperatures and how heat will be lost. Ideally buildings are well insulated, reducing the need for heating in the first place, and then what heating is required should be low carbon.

Our focus is to use SIPs (Structurally Insulated Panels), which embed the insulation into the wall of the building. This gives us maximum performance without making the walls overly thick. We then provide electric heating through a climate control air conditioning unit. If you’re on a green energy tariff, that will make your building low carbon.

Energy efficiency

As well as heating, all modern buildings use electricity in a variety of ways, for lighting, cooling, ventilation, etc. A lot of this energy use can be eliminated by good design too, by maximising natural light and ventilation. Efficient lighting and appliances keep energy use down – and that means lower bills and cost savings.

Our buildings are designed with A-rated windows that let in plenty of light while avoiding too much heat loss. We add skylights to increase natural light where necessary. When you do need extra light, we fit low energy LED lighting as standard. We can also fit solar panels as an optional extra, so you can generate your own renewable energy.


the construction industry is a major source of waste, as you may have noted if you’ve ever spent any time on a building site. It’s the single biggest contributor to landfill, with vast amounts of waste materials, rubble and mixed waste. Reducing waste in construction is to do with on-site practices, but it’s also to do with design and choice of materials. It is quite possible to design a building so that it can be dismantled and the materials reused, rather than being demolished into a pile of rubble that’s no use to anyone.

As a modular builder, we have a major advantage. Your buildings are made in our factory and only assembled on site. That means that we deal with any waste at the factory, which is so much easier than the ad hoc nature of building sites. We’re able to use exactly what we need, and reuse scrap in other projects.

Of course, there is the waste created within the building, which is a slightly different issue. But if you want to ask us about composting toilets, we can do those!


all buildings are, to a certain degree, an imposition on nature. Human convenience tends to come first, and we pave over the soil and keep down the weeds. Sustainable buildings leave more room for nature, through sensitive landscaping, creating habitats, and avoiding disruption to nearby trees and water courses.

All our sites vary, so we don’t have a one-size fits all approach to nature-friendly construction. We do always consider how our buildings will fit in with their surroundings though. We prefer the natural look of timber cladding, and we often fit green roofs. Planted with low-growing sedum, a living roof creates space for nature on the otherwise unused roof space of your building.

From our perspective, the outsized environmental impact of buildings is an opportunity. If buildings are a major cause of climate emissions, then the construction industry will have to be a major part of the solution too. We’re committed to that. Sustainability runs right through our business, including our choice of name. And we continue to experiment with new ways to ensure that our buildings are efficient, low carbon, and eco-friendly.