Regenerative Building – Sustainable Homes that Integrate with Nature
As an industry, construction plays a large part in our global carbon emissions, and for homebuilders this environmentally damaging output doesn’t end once the construction is complete.
As the BBC states, ‘Residential properties are responsible for between 17-21% of energy-related carbon emissions globally.’ With Net Zero targets, and ambitions for a greener future, this is cause for concern. Not least because carbon emissions are not the only waste produced by our homes.
The United Nations estimates that as much as 11% of global food waste comes directly from households, while in the UK we waste ‘more than three billion (that’s three thousand million) litres of perfectly good drinking water’ daily, according to Maintain Drain. They go on to explain that this amounts to ‘15 billion cups of tea’!
These shocking figures reveal a need for change. As Space 10 argues, ’we must think differently about how our homes impact wider environmental systems.’
But how can this be achieved, when the need for housing, food and water are all necessary parts of human existence?
Enter: regenerative building.
What is Regenerative Building?
Regenerative building can be loosely described as the next step up from green building (and still very much contained within this category). With regenerative building, ‘The goal is to move beyond net zero and generate net positive benefits,’ says The Holcim Foundation.
Some practitioners in sustainable architecture and construction refer to this style of building as a ‘living building’ and the image this conjures can help our understanding of what regenerative building could do for the environment and the community. This type of construction would not detract but add to its natural surroundings and encourage nature, rather than reject it.
Regenerative Building Strategies
In order to create homes and buildings that can have a positive impact on their local environment, it is essential to alter some traditional building styles and materials, and to ensure the most efficient use of materials and space for construction.
There are many methods of regenerative building, some already in use, others in the stages of design and a few theorised methods that have not yet been tested.
Green Rooftops
There are already a number of regenerative building strategies being used both in the UK and around the world but the most visually noticeable, and arguably most pleasing to the eye of these building methods, is the ‘green roof’.
Full of luscious colour, this type of house-topper has soared in popularity in recent years, and that trend is set to continue. According to Globe Newswire, the green roof business is a sector worthy of investment: ‘The global green roof market is expected to grow from $1.53 billion in 2022 to $1.80 billion in 2023 at a compound annual growth rate (CAGR) of 17.7%. The green roof market is expected to reach $3.31 billion in 2027 at a CAGR of 16.4%.’
However, the rising popularity and attractive appearance of a green roof is by no means its strongest selling point. As Homebuilding and Renovating Magazine explain, ‘Though green roofs look undeniably more attractive than most other roofing options, they’re not just style over substance. In fact, they can help your build function better and reduce its impact on the environment.’
The positive impact of a green roof on the environment is the more obvious benefit. As a green roof is covered in vegetation, it naturally becomes a miniature living green space. It absorbs carbon to purify the air, where there would otherwise have been lifeless material that held none of these benefits.
The benefits to the ‘build function’ created by installing a green roof are a little more surprising, and can include positive outcomes for both energy efficiency and water.
A New York Times’ report on the rise in popularity of the green roof, revealed that, ‘a green roof can reduce air-conditioning use in a building by as much as 75 percent.’ Sempergreen explains how this works, saying, ‘Plants absorb sunlight, 50% is absorbed and 30% reflected; so this helps to create a cooler and more pleasant climate.’ This, says Sempergreen, typically ‘means a 3°C temperature reduction in the city.’
This heat reduction is a benefit in itself, as is the reduction in energy usage and cost for those living in a green roof-topped home.
In regard to the water-related benefits of a green roof, Sempergreen explains that a green roof ‘absorbs rain water by the water buffering in the plants, substrate and drainage layer.’ This leads to a delayed and gradual discharging of rainwater, which ‘helps to stabilize the groundwater level, reduces the peak load on the sewage system and reduces the risk of flooding.’
So, the green roof, though far from ground level, can even provide benefits for our subterranean systems.
Use of Natural Building Materials
When not using the building’s surface as an opportunity for growing, there are still environmental benefits that can be had if you choose the right materials.
The best building materials to choose are natural, and locally sourced. Space 10 advises builders to, ‘Use locally-sourced natural materials such as straw and clay for new building work and insulation — abundant materials that can be safely returned to nature.’
Furthermore, The Holmic Foundation agues for builders to utilise ‘Building processes (that) mimic nature in that there is no waste output, but “waste” is used as input for a new, regenerative process.’
One natural building material that is growing in popularity is stone. And as well as being a natural material, Building Magazine emphasises, ‘Stone is typically stronger than concrete with one third of the carbon impact.’ As cement is made from limestone, which then has to undergo heat and labour-intensive procedures to be produced, using the limestone from the slabs cut straight from the quarry is a much more effective way to use the stone. ‘After all, that is what people did for thousands of years before cement was invented,’ says Building Magazine.
Another material that has always been used in construction but is now becoming more frequently utilised, and applied to more areas of a building’s construction, is wood. International Timber explains that, ‘The key reasons for timber’s increasing rise in popularity in the construction industry include high insulation, a promising thermal performance and high chemical resistance.’
Timber frames, beams and panels, like limestone, also require far less production before they can be put to use. They only need to be cut to the correct size. This means the carbon emissions associated with timber products are naturally a lot less than that of a manufactured product.
Bamboo is experiencing a surge in popularity as a building material at present, due to its rapid growth rate, durability and attractive appearance. It can be used in the construction of buildings, for furniture and the building of bridges. As explained by the World Economic Forum, ‘Bamboo is the fastest growing plant on earth. Many variants are ready to harvest in just three years, when they're cut down to their base from where they start to sprout again.’ This epitomises the essence of regenerative building, using a material that reconstructs itself once taken down.
There are many other natural building materials, such as soil, clay, adobe (which is a mixture of earth and water, dried in the sun and then cut into bricks), cob, cork, masonry, straw bales, and more. At present, stone, timber and bamboo are gaining the most attention through the media, and are subsequently growing in popularity but these are most certainly not the limit of your options.
Re-Use and Re-Purpose
So far, we have discussed options that apply to the construction of new buildings, however, wherever possible, regenerative building can and should make use of existing structures (as well as any items within those buildings that can be re-purposed). Recycling isn’t just an activity to be carried out around the home. Space 10 argues that we should ‘Retrofit for vitality: Restore and upgrade buildings to prolong their life, enhance energy efficiency, and create and uplift local communities.’ Why build new structures while leaving old buildings to rot?
Another primary benefit of retrofitting is that it does not require the adoption of unused land, therefore reducing the impact on nature and the natural landscape. Plus, says Space 10, we should ‘Reuse old building materials, furniture, and components to save costs, reduce demolition waste, and demand for new materials.’ This immediately reduces the carbon footprint of a building’s construction.
Recycling Water and Food Waste
As well as repurposing the buildings and their materials themselves, the recycling facilities provided within a new home can be key to ensuring its regenerative qualities.
Ensuring that homes are fitted with composting systems, either in the garden, or wormeries in an apartment, is a great way to minimise food waste while creating something new from unwanted provisions that can be used for growing plants or fruit and vegetables. Space 10 goes even further, suggesting, ‘Move nature’s regenerative systems into kitchens: compost food scraps from home-grown produce using countertop wormeries.’ This could create an endless cycle for the growth and composting of food from home.
The recycling of water can be encouraged by homebuilders through the addition of water butts in the garden, or outside the apartment building. This collected rainwater can then be used to water plants both inside and outside the home, grow fruit and vegetables, and even clean cars!
A more dramatic, and effective, approach to wastewater management is to install on-site water treatment facilities. This might sound like an expensive option, however, HMC Architects argues that although there is a high initial cost, the high impact on water conservation, ‘thereby results in long-term resource savings that arguably outweighs short-term financial projections.’
As the Holcim Foundation argues, giving back to the environment means ‘Designing buildings that operate as power plants and water treatment plants, by covering their overall demand as well as generating surplus for the benefit of the overall urban energy and water balance.’ This is truly regenerative, as it operates on a positive output of vital resources.
Not Just Energy Efficiency but Energy Production
Although energy efficiency is important in every home, a regenerative building should be capable of creating and sharing its own energy.
Space 10 advises builders to ‘Integrate solar, green hydrogen, and other renewable energy systems into the exterior and interior design of the home to capture and provide off-grid power.’ And HMC Architects recommends regenerative builders that the ‘building could also serve as small scale energy resource for the surrounding community.’
There are many renewable energy systems rising in popularity for domestic buildings, such as solar panels and air source heat pumps, but, as HMC Architects says, ‘Every day, new technologies are coming online such as biodigesters which convert solid waste into energy which can be used by the building.’ So, there could be a broadening of renewable energy system options in homebuilding available soon.
Sharing Is Caring
Almost all practitioners in regenerative building design and strategies, talk about a need for the sharing of goods and facilities, in order to achieve a genuinely regenerative community.
This can mean quite a change in lifestyle for some individuals but can be encouraged in the development, nonetheless. Space 10 calls for residents to, ‘Share household objects through joint ownership, as-a-service models, or community libraries to extend their life and use, and promote recycling.’
To provide any facilities that could be used for residents to share items, such as books, tools, equipment or transportation, would be a great step towards achieving this goal without banning individual cars from the development. Similarly, ensuring residents are aware of local transport facilities, routes and times of services, is a good way to encourage the reduction in single occupancy car use. You might even be inclined to encourage a car share for developments outside the city, which have commuter-residents.
Community allotments are also a fantastic way to encourage residents to grow and share their own food, especially when the average waiting time for an allotment in the UK is over two and a half years, or over 10 in certain London boroughs… and don’t forget to keep those compost bins handy for any scraps!
Why Follow Regenerative Building Models?
If you’re thinking this all sounds great but like a lot of unnecessary work for a homebuilder, then think again.
The sustainable features of a property are fast becoming one of their strongest selling points, as Country Living magazine reported, a ‘Study conducted by E.ON Energy found that 89% of prospective buyers want sustainable homes that are kind to the planet.’
And with sustainability now so important to a buyer, it is important to promote the sustainable benefits of your current developments. We can also encourage sustainable living within these developments, while illustrating your ESG credentials, with our Sustainability and Community Guides.
Providing advice for residents on how they can live more sustainably is a welcome addition to handover documents. A study into UK water consumption found that, ‘While people are unsure about the amount of water they consume, the vast majority (68%) say they are willing to reduce the amount of water they use at home to help protect the environment.’
And finally, the benefits of regenerative building do not end with the environment. ‘Medical studies prove that a life far removed from nature can cause psychological as well as physical and cognitive issues’, according to the Holcim Foundation. So, for the benefit of your residents’ mental wellbeing, an imperative component in building happy communities, it is worth deploying regenerative building strategies wherever you can.