We all know what a light well is. It is an open space in a building that is left unroofed to allow light and air in. It reduces lighting bills, and helps control the temperature. And it is passive – no power is used.

And we all know the alternative to light wells used by many people who don’t have the budget for fancy architecture, but who want all those benefits. It is a skylight.

Install a skylight in your roof and sunlight streams directly into your home. Your kitchen is flooded in illumination for hours, and it costs you nothing. It even heats the space during hours of direct sunlight. And if you make sure it is double glazed, you don’t lose heat the rest of the time.

A skylight is one of the simplest ways – but only one of many simple ways – to turn an ordinary building green.

Turning buildings green is nothing new. It is as old as civilization, and then some. Stone age man lived in caves. It was convenient, but it also meant that he didn’t have to knock trees and destroy vegetation to create his shelter.

At many points in our history we have tried to work with the environment to provide shelter that was passive and low-impact. An example is the underground dwellings of Cappadocia. Cappadocia is a region in south central Turkey. In summer it is dry and arid. In winter the temperature plunges below zero, and snow covers the ground. It is a region of extremes.

What sort of dwelling will protect you from the climate? You need something with shade and coolness for the summer, but something well insulated for the winter. The locals came up with the perfect solution.

For over two thousand years the people of Cappadocia have dug into the ground. They live in elaborate networks of caves. The caves are on multiple levels, and some of the complexes are large enough for several thousand people.

A natural cave provides a very stable temperature, not varying by more than a few degrees between summer and winter. Turns out an artificial cave has the same properties. The cave dwellers were kept warm in winter, and cool in summer. And it was done by working with the landscape and environment. Warmth was achieved without having to burn the scant vegetation. It was truly passive housing, two thousand years before that became trendy.

What are green building products and materials?

Green building planning

Going green in architectural terms involves two steps – using green products and materials, and green design. So what materials are green?

Some are obvious. Some less so. Let’s look at just five.

Traditional Cob

Cob is an ancient mixture of clay-based soil and straw. It is still used in many parts of the world for walls and floors. It is labour intensive, but affordable. The thick walls provide great energy efficiency and insulation, and it is a very healthy material.

Recycled steel

Steel is the most recycled metal in Europe, and the good news is that there is no reduction in its strength when recycled. The recycled steel is as good as new – one of the few truly closed recycling loops. It makes great frames for construction, being versatile, cost-effective, durable, and low-maintenance.


Bamboo grows far more rapidly than wood, and can be immensely strong. How strong? Twice as strong as concrete, and slightly stronger than steel! It is a perfect building material. But it gets better. Bamboo plantations are a haven for wildlife, and can be located in areas with poor soil. In fact, the roots of bamboo can prevent soil erosion. Win win. No wonder it is catching on in the west.


From managed forests, wood is one of the most environmentally friendly building materials. It is a naturally renewable resource, and very cost effective. And there is the aesthetic advantage – a wooden structure is like wearing your green credentials on your walls. It’s nice to show off.

Mycelium composite

Now we are moving into the materials of the future. Researchers have been experimenting with combining fungi with other substances to produce strong, light and sustainable building materials. The end result is a strong material that is resistant to mould, water and fire. It can even be brown organically into specific forms, saving time and money. It is still at the experimental phase, but the day may come when we are living in mushrooms!


Like fungi, ferrock is an experimental material, but could prove a very green alternative to concrete. It is made from waste steel dust and silica from ground up glass – both resources that come from recycling. Once the mixture drys it is stronger than concrete – and it absorbs carbon in its production, making it a carbon negative product. We will be hearing more of it.

What are the design principles of green building?

Agreement on green building

There are so many, but like materials, let’s look at five.

Energy efficiency

A green building will be insulated to prevent heat loss. But it will go further – light wells and skylights will reduce the need for artificial light. Proper ventilation will reduce the need for air conditioning. A building can be energy neutral. The government’s decision a number of years ago to introduce energy ratings for buildings has moved us a long way along this road.

Water conservation

A green building will conserve precious water. The piping will not leak, and water will not be wilfully wasted. Toilets will flush with minimum volume, and taps will be automated to switch off automatically. Waste water can often be recycled and reused. In Japan it is common that the water in the wash basin of a restroom is later used for flushing.

Indoor air quality

A green building will have good ventilation to allow a flow of good air through the building. This not only makes the indoor environment healthy and pleasant, it will help with temperature control, reducing energy bills.

Resource conservation

In the construction and maintenance of the building thought will be given to using renewable materials ahead of non-renewables. This starts with the construction, but must be carried right through, to the cleaning products used to maintain the building, and the paints used to touch it up. It is a mindset that needs to be carried through.

Optimise site potential and building space

This is down to the initial design. Rooms and spaces have to be big enough for their purpose. They don’t need to be wastefully big. High roofs that lose heat are an obvious example. Another example is orienting the building to make the most use of the natural light. Facing your biggest windows north is not optimising the site potential!

How do green buildings reduce waste?

During construction green architecture reduces energy, water and materials being used for the build. In a previous blog we have dealt with how the construction industry can reduce the amount of waste going to landfill.

During the lifespan of the building it is important to provide on-site solutions such as recycling bins and compost bins to reduce waste. And a green building will cost less to run. So energy bills are down, and that leads to a reduction of waste off-site.

Finally, instead of demolishing a building after it has reached the end of its use, it can be deconstructed. Materials can be recovered for new projects rather than going to landfill.

Green architecture is a decision we make at the start of a project, but it can have a major impact throughout the life of a building. So it is worth that initial effort.