Posted on

Rain City Strategy: A Green Approach to the Future on the Wet Coast

Green Roof Installation

Sourced from Vancouver is Awesome

As Vancouver enters an uncertain summer, what better time to talk about every Vancouverites’ favourite subject. No, not The English Bay barge, the rain.

Some climate predictions have the annual rainfall in British Columbia rising by 6 per cent over the next twenty-eight years. The implications are stark: flooding, sewer overflow, and increased water pollution. The IPCC Sixth assessment says an increase in extreme precipitation for our region is “very likely.” Good thing then that the City of Vancouver has embraced Green Rainwater Infrastructure (GRI).

Think of GRI as a means of incorporating nature to solve water-related problems caused by rain. Moreover, GRI improves water quality, enhances biodiversity, and creates ecological habitats. GRI should not be confused with grey infrastructure, the antiquated system of pipes, treatment plants, and reservoirs that has long been the method of managing water resources. Rainwater management requires a holistic approach involving GRI, land use and, yes, those old pipes.

GRI is central to the COV’s Rain City strategy, a long-term plan to turn Vancouver into a “water sensitive” city. The strategy shows a vision for a future where the city has been “reimagined” in its design to “embrace rainwater as a valued resource [for] communities and natural ecosystems.” To do this, the strategy aims to remove pollutants from captured rainwater, increase porous land, limit the volume of rainwater getting into the pipe system, “harvest” rainwater, and increase green spaces. The end goal: Capture and clean 90 per cent of our average rainfall, and manage 40 per cent of runoff from impervious areas by 2050.

Read the full article

Posted on

What Are Roll-Out Green Roofs?

An image of a roll-out green roof domestic project

The roll-out green roof is a simple, low maintenance sedum green roof system where each element is supplied separately and installed layer by layer. It is an effective way of greening a roof deck and bringing a sense of nature to built-up areas.

Key Advantages

  • lightweight systems available
  • total build-up depth – 100-150mm thick
  • simple vegetation – mainly sedum
  • drought tolerant
  • saline tolerant
  • low maintenance requirement
  • irrigation system (optional)

Extensive green roofs are designed to be lightweight. Therefore, they can be used on a large variety of structures.

The sedum plants we use have been selected to be easy to manage and do not need a large amount of watering, making them ideal for areas which may be overlooked but are difficult to access and maintain.

The sedum blankets contain a mixture of different species of sedum, specifically selected to provide a a variety of different textures, colours and flowering periods and are supplied with at least 85% coverage. They are designed to give consistent, all year round coverage of vegetation throughout the year.

Mixes of wildflowers, herbs and bulbs can also be incorporated into the blankets. We supply healthy, freshly cut sedum blankets.

For more information, please click here.

Posted on

Can Green Roofs Help To Reduce Energy Bills?

installing M-Tray modular green roof

Britain’s cost of living crisis has intensified over the past year and, with energy bills set to increase again after the announcement that the cap on prices will rise this spring, is it any wonder that UK house buyers are changing their search requirements, wanting more sustainable, eco-friendly housing than ever before.

Ofgem, Britain’s energy regulator, announced that, from April 1, 2022, customers on default tariffs paying by direct debit will see an increase of £693 per year on their energy bills, whereas prepayment customers will see an increase of £708.

The increase is likely to affect an estimated 22 million households in the UK. It seems likely this is not the last rise, either, with analysts suggesting the average household energy bill will soar to £3,000 a year.

fully installed green roof houseboat

‘Rising energy bills are obviously a great concern for the majority of homeowners in the UK at the moment,’ says Karly Williams, sales and marketing director at David Wilson North Thames.

‘This has really been prioritised in recent years – particularly with the growth of green technology and the growing importance of energy performance certificates,’ she says.

Jenny Anson, head of sales at Pocket Living, agrees, having noticed a real shift in Londoners’ house-buying patterns: ‘Throughout 2021 we saw a significant increase in home buyers looking for a property that will help them reduce their carbon footprint, and we will no doubt see this continue in 2022,’ says Jenny.

‘A key concern, for many, is the type of heating installed in a home, especially following the recent steep price hikes in gas bills,’ she says.

‘People appreciate the importance of moving towards more sustainable heating methods, the long-term savings inherent in this, and the protection it offers from future rises.’

Pocket Living has committed to future-proofing its Harbard Close development in Barking by kitting out apartments with MVHR heat recovery ventilation systems and LED lighting, as well as installing solar panels that contribute to the power supply to communal areas.

Nigel Fleming, sales and marketing director at JTRE London, whose latest development Triptych Bankside is incredibly green, attributes the rise in a preference for energy-efficient housing to Covid.

‘The pandemic has put sustainability front and centre, with today’s consumers more conscious than ever, from where they buy their coffee to their choice of transport or connection to brands,’ says Nigel.

‘At Triptych Bankside, sustainability has been integral to the design from the outset including a passive design approach, a new combined energy centre supported by PV solar cells, through to brown roofs and bird boxes that encourage wildlife and sprawling landscaped gardens.’

For the full article, please click visit the Metro website by clicking here.

Posted on

What is a Biodiverse Green Roof?

aluminium edging bar green roof

Biodiversity should not be viewed as a project afterthought but should be at the forefront of all city and project planning. Apart from being vital for our survival as a species, biodiversity also supports business worth €40 trillion ($42.2 trillion US), representing half of the global Gross Domestic Product (European Commission, 2020). So how do we expand on total net urban biodiversity in the fastest way possible?

Green roofs should be as biodiverse as possible given project constraints. Though perhaps controversially, I think that we can gain higher net biodiversity by expanding our definitions of what encompasses a biodiverse green roof. I sometimes worry that an almost too strict view of the definition of a biodiverse green roof can be damaging for the task at hand as an all-or-nothing mentality can result in fewer green roofs being built, and so the net total urban biodiversity might suffer.

In the end, a low biodiverse green roof is infinitely better than no green roof.  A deeper, diverse, species-rich green roof is even better, but not always practical. Our best path is often to green as much as possible, and then seize as many opportunities as we can to add greater biodiversity.

Are Green Roofs Natural Spaces?

Green roofs are not genuine natural spaces. In nature, you do not find a relatively thin profile of manufactured lightweight soil with low capillary capacity. The profile of extensive green roof is often less than 10cm (4”) deep and has a drainage layer underneath the system, allowing excess water to fall out of the profiles, which is in stark contrast with garden soils, where water will take weeks to percolate into deep cavities, often 1.5-3m (5-10 ft) deep. There it remains accessible to many common plants which can access this water reservoir during droughts. Since many species of plants suck water out of up the upper layer with their deep root systems, water will automatically be drawn upwards. This aquifer-type reservoir system can supply plants with water for weeks and weeks thereby bridging droughts.

Also, the final biodiversity outcome of a green roof depends on planting time, which might favor certain plants over others. It also depends on the next season: is it wet or dry, cold, or hot? It may also depend on extreme stress levels that reduce or even eliminate several species allowing others to overtake them. It further depends on maintenance: did they fertilize, and with what? Have they added new species? And it can depend on the impact of micro-climates such as the heat reflection of walls and windows, wind tunnels, shade, you name it.

Overall survival on a green roof is determined by the level of tolerance for temperature (too hot or too cold); water (too little or too much); and light (sunny or shadey). Plants that can tolerate these extremes the best will often survive on a green roof.  For these reasons, there are, of course, more possibilities for higher amounts of biodiversity on intensive vs. extensive green roofs. 

For the full article, please click here.

Posted on

Lightweight Wildflower Green Roofs

wildflower M-Tray green roof

Our M-Tray® wildflower roof system consists of specially-designed trays with bespoke substrate mix and native wildflowers. Easy-to-carry trays which click together to form a seamless green roof. Sedum/Wildflower mix grown from seed at our own UK nurseries. Achieves a fire classification of B ROOF t(4) and was tested in accordance with CEN/TS 1187 Test 4. 

As well as the sedum trays, Wallbarn also supplies a sedum/ wildflower version of M-Tray® for use on green roof systems.

Biodiversity is becoming more popular for urban greening schemes as it has been proven that a large mix of native English flowering species is the best way to attract and promote wildlife such as bees, butterflies, other insects and birds into these roof spaces. By replicating what is happening out in the fields on urban roofs we can help to replace what has been lost and improve the environment.

Wallbarn sows a low-density amount of sedum species to give a year round green and good level of ground cover and adds, again from seed, a mix of wildflower species which contain the following characteristics:

  • They are low growing species with as much succulence as possible
  • They are all native to UK / northern Europe
  • They are perennial and hardy
  • They will grow in low nutrient substrates
  • They have proven to improve biodiversity

A few factors need to be borne in mind when considering wildflower roofs:

  • Flowers can grow tall and die back to leave dead grasses and stems, which can lead to a fire hazard
  • Wildflowers will not provide the same ground coverage or year-round greening of sedum roofs
  • Wildflowers take longer to grow and flower than sedum
  • Wildflowers often require 2 years before flowering and may not return year after year without re-seeding
  • Some wildflowers will not flower in certain years, performance depends heavily on the weather that year
  • Wildflower roofs require more maintenance than sedum roofs

The  sedum / wildflower ratio is designed to complement each other and provide variety and attractive spaces across the summer but also with a sufficient amount of coverage and “green” throughout the year.

Bespoke options are available.

To find out more, please visit – https://www.wallbarn.com/green-roofs/m-tray-wildflower/

Posted on

Green Roofs Are Being Considered to Support Denver’s Future Amidst Change

Turing House - Wildflower M-Tray near Rooftop Rail

As climate shifts cause complex changes across local, regional, and global environments, residents face new questions about how to keep communities viable into the future.  Denver policymakers help citizens establish long term visions and goals in plans then implemented by enforceable regulations. This is true across Denver City departments, including Community Planning and Development (CPD), where codes and regulations that shape building projects are created and updated. The work embodies the community’s shared priorities, articulated by the Mayor’s Office, City Council, and through focused collaborative partnerships between City and County of Denver (CCD) teams and engaged residents, subject matter experts, and industry representatives. As part of this, green (vegetated) roofs offer potential benefits tied to mitigation of climate change and biodiversity loss, adaptation, resiliency, resource balance, and ecological health. This article provides an overview of various policy initiatives in Denver and how they relate to green roofs. 

Denver’s Comprehensive Plan 2040, adopted through City Council in April 2019 after 18 months of community collaboration, provides high level guidance for supplementary plans and regulations. The Plan envisions a healthy, prosperous Denver community empowered to persist into the future, existing at the intersection of equity, affordability, and environmental health. Current and emerging building project codes, policies, and initiatives steer development in service to this shared ideal, with several offering synergies with green roof opportunities.

Green Buildings Ordinance

Denver’s Green Buildings Ordinance (GBO), adopted in November 2018, replaced the voter initiated Green Roof Ordinance (GRO) approved a year prior. The GRO, then GBO, allowed citizens to vocalize a shared desire for building projects to contribute towards climate change mitigation and the health of the community. Members of CPD and the Denver Climate Action Team (now part of the Office of Climate Action, Sustainability and Resiliency (CASR) led a yearlong community task force to adjust the ordinance to fit the specific environment of Denver. The committee added flexibility to the initial GRO, allowing more building teams to replace exemptions with beneficial, affordable solutions to meet requirements.

Benefits observable almost four years since adoption of the GBO include: several hundred new roofs combating urban heat island effect; over 100 buildings achieving higher than code required energy efficiency; over 30 buildings third party certified as delivering higher overall performance; and approximately 65 buildings offering enhanced green space onsite or through a contribution to the Green Building Fund. Notably, few green roofs have been developed specifically to meet GBO requirements, as other options have proved to be a better fit for project teams. As other regulations advance, building team preferences are projected to shift amongst GBO options. In the context of Comprehensive Plan 2040 goals, green roofs may gain popularity as a GBO option, and contribute towards Denver’s positive ecological evolution, and future livability.

For the full story, please click here.

Posted on

How To Water Your Green Roof

Green Roof Irrigation System

Even hardy sedum and wildflower green roofs will require irrigation during periods of dry weather (3 weeks without rain during spring, summer) or very hot weather. If the roof starts to turn red it is in distress and requires watering.

Simple, manual irrigation

For smaller (typically less than 50m2) easy to access green roofs users should safely gain access to the roof and irrigate manually, e.g. a hosepipe, watering can.

Manual irrigation system

Tap fitting irrigation kit for extensive green roofs with standard fittings and 180° spray nozzles and 16mm pipe. For attaching to garden tap fitting for ad hoc manual irrigation (supplied without water filter).

Assembly instructions

Please see the video to the right

Unpacking

Lay out all of the components and familiarize yourself with all of the parts.

Supply

To reach a ground level water supply from a rooftop we recommend you run your 16mm piping down some existing vertical guttering. Check your water pressure: it needs to be at least 1bar.

Laying your pipe

Lay piping at the same time as you are laying your trays. Line up your 16mm piping flat on the ground, laying it in between the trays.

Positioning your risers

180° risers will produce a 3m spray arc on a standard 2 bar pressure tap. Position the risers, so that the jets overlap ensuring all of the green roof gets adequate water.

Pierce piping

Use the yellow barbed key to puncture your 16mm pipe ensuring your holes are no more than 3m apart so their sprays overlap.

Attach jet to riser

Insert the vertical rigid riser into the hole you have created in the pipe, then screw clockwise. Point the jets away from walls and upstand.

Attach riser

Select the appropriate Vari-jet nozzle for your tray layout (360° or 180° if up against a wall) and attach to the top of your riser.

A 90° jet is also available.

Pipe joiners

3 x types of joiner are supplied to allow you to extend/change the direction of irrigation:

  • Straight
  • Elbow (right angle)
  • T-junction
  • Plumbing

Connect to your water source: insert your 16mm pipe directly into your tap connection (filter optional).

Filter system (optional)

We recommend a filter system, to be fitted between the tap and your piping, in order to prevent the jets clogging with grit or hard water.

Terminate your system

Insert the straight-ended stopper into the piping to terminate the system.

Automated holistic irrigation system

Bespoke, sophisticated irrigation systems designed by horticultural and irrigation experts. Roof scale plans would need to be reviewed to produce specific, tailored irrigation system suited to the individual aspects and constraints of the roof. Aspects such as size, height, orientation and exposure, water pressure etc. are considered when designing the system.

Web based control systems which monitor substrate moisture levels, leak detection and irrigation schedule are available. A large range of different designs at different price levels are available.

These systems are typically for largescale green roofs.

Please click here for more information.

Posted on

General Benefits of Green Roofs – Biodiversity

Sedum and wildflower green roof flowers

It is now well documented that green roofs play a key role in helping to create biodiversity by providing important refuges for wildlife in urban areas.

A recent study by Sydney Marie Gonsalves at the Portland State University outlined the following in their introduction:

Green Roofs and Urban Biodiversity: Their Role as Invertebrate Habitat and the Effect of Design on Beetle Community

“With over half the world’s population now living in cities, urban areas represent one of earth’s few ecosystems that are increasing in extent and are sites of altered biogeochemical cycles, habitat fragmentation, and changes in biodiversity. However, urban green spaces, including green roofs, can also provide important pools of biodiversity and contribute to regional gamma diversity, while novel species assemblages can enhance some ecosystem services. Green roofs may also mitigate species loss in urban areas and have been shown to support a surprising diversity of invertebrates, including rare and endangered species. In the first part of this study I reviewed the literature on urban invertebrate communities and diversity to better understand the role of green roofs in providing habitat in the context of the larger urban mosaic. My review concluded that, while other factors such as surrounding land use and connectivity are also important to specific invertebrate taxa, local habitat variables contribute substantially to the structure and diversity of urban invertebrate communities. The importance of local habitat variables in urban green spaces and strong support for the habitat complexity hypothesis in a number of other ecosystems has led to proposals that “biodiverse” roofs— those intentionally designed with varied substrate depth, greater plant diversity, or added elements such as logs or stones—would support greater invertebrate diversity, but there is currently limited peer-reviewed data to support this.”

“In order to address the habitat complexity hypothesis in the context of green roofs, in the second part of this study, I surveyed three roofs designed primarily for stormwater management, three biodiverse roofs, and five ground-level green spaces, from March until September of 2014 in the Portland metropolitan area. Beetles (Coleoptera) were sampled bi-weekly as representatives of total species diversity. Biodiverse roofs had greater richness, abundance, and diversity of beetle species compared to stormwater roofs, but were not more diverse than ground sites. Both biodiverse roofs and ground sites had approximately 20% native beetle species while stormwater roofs had only 5%. Functional diversity was also higher on biodiverse roofs with an average of seven trophic groups represented, while stormwater roofs averaged only three. Ground sites, biodiverse roofs, and stormwater roofs each grouped distinctively in terms of beetle community composition and biodiverse roof communities were found to be positively correlated with roof age, per cent plant cover, average plant height, and plant species richness. These results support the findings of previous studies on the importance of local variables in structuring urban invertebrate communities and suggest that biodiverse design can reliably increase green roof diversity, with
the caution that they remain no replacement for ground-level conservation.”

To read the full report, please click here.

How Can The M-Tray® Help?

Our bespoke design allows us to supply the best quality vegetation to site. The fully established, mature sedum or wildflower plants, are contained within easy-to-carry trays which click together to form an almost invisible join.

M-Tray® has been designed and developed by Wallbarn in the UK and is the subject of Community Registered Design (No. 002953943-0001) and US Design (Application No. 29/553,129).

To visit the dedicated area of the site, please click here.

Contact Us

Wallbarn can advise and assist on all aspects of scoping, installing and maintaining your green roof project.

Just pick up the phone, ask a question using the live chat facility on this site or send us an email at info@wallbarn.com and we’ll get back to you next working day at the latest.

Currently Browsing: General Benefits of Green Roofs – Biodiversity
Posted on

What Are The Key Benefits of a Green Roof?

How Does The Appliance of Science Deliver Green Roof Success

Improving the Environment

Carbon sequestration
Plants absorb carbon dioxide and release oxygen during photosynthesis thereby counteracting emissions and help towards net zero.
Air quality. Sedum and other green roof plants absorb soot and other pollutant particles which helps to improve air quality.

Urban Heat Island Effect
The evaporative cooling of green roof vegetation also reverses the heat reflecting effect from hard impermeable surfaces such as waterproofing membranes and concrete. The plants actually absorb heat and turn that heat into energy to grow, unlike concrete or brock which will absorb heat during the day and radiate it back into the atmosphere, artificially increasing the ambient air temperature.

Micro Biodiversity
Green roofs can replace and create habitats that have been lost as a result of urban development and replicating what was at ground level to roof level; encouraging a range of insects, birds and other wildlife.

Macro Biodiversity
Green roofs can be used to allow the creation of ‘green bridges’ or ‘bee corridors’ through the built environment. This not only helps with the aesthetics of the area but also allows the natural flow of flora and fauna through urban developments.

Acoustic performance
An extensive Green Roof can insulate up to 40dB and an intensive Green Roof can insulate up to 50dB. This reduction in transfer of noise can make a noticeable difference in highly dense urban environments.

Improving the building

Protecting the waterproofing
The build-up of a green roof protects the waterproofing layer by covering it. This reduces the impact to the membrane from UV, temperature fluctuations and other atmospheric pressures. A green roof protects the waterproofing by mitigating expansion and contraction. This protection prolongs the life of the waterproofing.

Reduction in solar gain
Returning moisture to the atmosphere through evapotranspiration, solar gain can be reduced. Moist air helps trap dust and some gasses which reduces pollution

Amenity and well-being
Green roofs have a positive visual impact and can provide valuable outdoor recreational areas.

Creates more space
A green roof can create an amenity or leisure space for the building which maximises the footprint and gives greater financial yield. Green roofs can include playgrounds and play areas, ornamental gardens or areas in which fruit and vegetables can grow. They have been shown to improve people’s mental health.

Building performance

Insulation
The evaporative cooling effect combined with increased insulation or thermal mass can reduce the need for summer cooling (air conditioning etc) which results in reduced carbon emissions.

Scoring BREEAM points
Improving the energy performance of buildings and embracing Green Roofs helps to meet standards such as the code for sustainable homes and BREEAM. It also helps to meet planning requirements and revisions in Part L Building Regulations.

A development incorporating a Green Roof can earn up to 6.2 points on an Eco Homes score. It can also score substantial points for sections LE04 and LE05 using the ecology of the roof to enhance plant species, local biodiversity and water storage.

Aiding planning consent
There are a number of central and local Government initiatives (including the London Plan) to encourage the greening up of both existing spaces and new build developments and often planning consent is directly tied to green roofs and sustainable drainage systems.

Reduces whole life costs
Typical roof installations have a life expectancy in the region of between 15 and 20 years. The building of a green roof system has been shown to have a life expectancy in excess of 50 years. This means the whole life of the development will be significantly lower than a traditional roof construction.

Drainage

Water attenuation and flash flooding
Urbanisation and land development creates hard impervious surfaces, which absorb only 5% of rainfall. The remaining 95% of the rainfall becomes run off. This puts enormous strain on sewers and river systems. Adding a green roof can capture over 50% of rainfall and will slow down the time before the run-off rainwater hits the drains for up to 1 hour. This is a major benefit in reducing the risk of flooding.

Green roofs as part of a SUDs solution
Sustainable drainage and water retention and attenuation are major parts of the SUDs design and method. As well as capturing stormwater and slowing the run-off, green also provide a filtering and cleansing benefit.

Water discharged from a green roof is proven to be cleaner than from concrete surfaces and this water can be stored and recycled within the building / masterplan development via grey water schemes.

For more information, please click here.