Tag: green roof


The two types of green roofs: extensive vs intensive

If you’re interested in installing green roofs but are unsure of the different types, this blog is perfect for you. Carry on reading to understand the difference between extensive and intensive.  

Extensive green roof –

What are extensive green roofs?  

They are designed to be low-maintenance, lightweight systems with no general access. Typically, they have thin layers of the substrate to keep depth and weight to a minimum.  

The substrate depth of extensive green roofs is smaller than that found in intensive roofs, usually around 100-150mm. Because of their shallowness, extensive green roofs usually provide aesthetic ad environmental purposes. Rather than functioning as accessible roof space.  

Usually, extensive roofs use sedum vegetation due to its ability to flourish in harsh environments. They are able to withstand weather, especially wind, droughts, flooding, and extremely high or low temperatures.  

How to get the vegetation on the roof –  

Extensive green roof installations often come ready-made. They are rolled up in mats containing 10-22mm of growing medium and vegetation, meaning that it’s easily transportable to the installation site. These mats are usually laid upon another shallow layer of growing medium, which is then placed on the filter sheet and protection mat.  

The cost of extensive green roofs –  

This type of green roof tends to be a lot cheaper to buy and install compared to the intensive green roof. It is also often one of the most popular choices for residential properties because they are much lighter. They cost around £50 – £100 per square meter, however, they cost £75 on average.  

Green roofs - advantages a handful of the most important information

Intensive green roofs –  

What is an intensive green roof?  

They consist of much deeper substrates which give far greater scope to design and grow more complicated and elaborate gardens onto concrete structures. Intensive green roofs involve intense landscaping. They are suited to roofs with a highly visible presence or public access. 

The substrate depth of intensive green roofs is at the very least 120mm, and usually over 200mm, making it a lot deeper than the extensive. Because the substrate depth is deeper, they are able to support more vegetation. Such as: 

  • Flower beds 
  • Trees 
  • Shrubs 
  • Lawns 
  • Water features  
  • Benches  
  • Gravel paths  

Intensive green roofs are intended to replicate what can typically be found at ground level in the natural landscape, and in places such as parks and gardens. In fact, they are often referred to as roof gardens or parks.  

The cost of intensive – 

They are the more expensive type of roof; this is because they resemble conventional gardens. The maintenance and the running costs will be higher than extensive. They can also be highly expensive to install because they require elaborate drainage systems.  

Intensive green roofs can cost between £60 – £200, however, they average around £130.  

Design and Inspiration

A beginner’s guide to know all about green roofs

What is a green roof? 

green roofs are buildings that are that is covered completely with vegetation and a growing medium, planted over a waterproofing membrane. The roof may include a root barrier, which is a physical wall underground placed so that plants may cohabit together. Also, a drainage and irrigation system, so the roof doesn’t get damaged. An irrigation system is an artificial process of applying controlled amounts of water to land to help the production of crops. The drainage system is so the roof doesn’t get filled up with excess water because it could cause a leak.  

What are the types of green roofs?

There are two types of green roofs and they are: 

Intensive: A tensive roof is one that is used as a recreational space, and often includes similar features to traditional parks and gardens. For example, intensive roofs would usually have shrubs, trees, paving, lawns, and even water features. It is basically a garden on your roof.  

Extensive: Extensive roofs normally intend to be viewed from a different location as visual or ecological features. These also do not have people walk on them apart from for Maintenace purposes.  

Why are they so popular and what are the benefits?    

The green roof market in 2017 was growing by 17% each year. This is because green roofs are very eco-friendly and they are a good way to promote environmental sustainability.  They also have a lot of benefits one of the main ones is that they reduce temperatures and remove heat from the air. In the summer green roofs protect the building from solar heat, and in the winter green roofs minimise heat loss through the added insulation of the roof. They’re also very aesthetically pleasing to look at and that’s why a lot of people go for the extensive roof. Another benefit is that green roofs reduce the risk of fires because of the high water content in the plants. That is a great thing because green roofs provide habitats for birds, insects, and other wildlife.  

Green roofs do tend to be more expensive than a traditional roofs, because of all the extra support and the layers that need to be installed.  You would need to maintain it by removing the weeds and applying fertilizer so that the plants carry on growing. You could also have drainage issues, which could lead to excess water flow. However, the roofs also have an average life span of around 40 years. That would end up saving you around £144,397.00 in the long run.  

As you can see there are far greater benefits for a green roof. If you are an environmentalist or if you’re not this roof provides a lot of positives for the environment and in general.  Over the last few years, they have been becoming a lot more popular and the sales of them are growing.

Gallery of Sky Garden House / Guz Architects - 2
A green roof example