Monday, 16 November 2009

Green Roofs

Aiming to remain eco-aware in my design work I attended a course on green roofs recently, organised by the Brighton Permaculture Trust and Brighton and Hove Building Green. The tutors were Dusty Gedge and John Little, and we learned about the ethos and theory of living roofs, as well as the practicalities of construction. It was gratifying to meet people from many different countries, and many different disciplines, all of whom were interested in this topic.
Here are some photos of a community building and housing project we visited in Brighton.

What are green roofs?

For anyone who hasn’t heard of green roofs and the benefits they can bring, here’s just a very short introduction. The term refers to a flat or gently-pitched roof (usually less than 30 degrees) with a growing medium laid over a root-resistant waterproofing layer, which supports living plants. Whilst this may seem somewhat unusual to us in the UK, their use is increasing, with cities like Sheffield at the forefront and many others, including London & Brighton, adopting them for many of the situations listed below. They are a centuries-old tradition in Scandinavian countries, and they have been used for a long time in other European countries. Many countries, most notably Germany and many states in the USA, promote their use as part of their town & city planning laws – often requiring a percentage of green roof space as part of the conditions for granting development permission.

Why is this? What are the advantages?

Firstly, and most obviously, is the beneficial effect of adding extra “green space” for aesthetic and ecological purposes – especially in large cities where roof space can be over 75% of the geographical area. However - and here’s why they’re important for planners and commercial interests - they have solid economic benefits. Green roofs can increase the thermal insulation of roofs, resulting in lower energy requirements (and hence lower carbon footprints) for winter heating and summer cooling. The presence of the green roof can help to protect the waterproofing of the roof by removing exposure to UV radiation and reducing the temperature extremes encountered - which prolongs the life of the roof. The evapo-transpiration of the vegetation produces a cooling effect that mitigates the higher temperatures encountered in cities (the “urban heat-island” effect), improving the climate, reducing humidity, and lowering energy demand. The vegetation can also help improve air quality by filtering out contaminants and adding oxygen. Green roofs help to reduce both the volume and rate of rainwater run-off which needs to be managed during storms, giving economic benefits in reduced storm-water engineering requirements and costs.

Don’t they damage buildings and become a maintenance chore?

The answer is most definitely NO! Provided that the green roof is designed to be within the load-bearing capacity of the building and the root-protected waterproofing and drainage is properly addressed, an extensive green roof is very low maintenance.

There are several “flavours” of green roof, mainly associated with the depth and fertility of the soil (more properly, “substrate”) and hence the type of planting which will succeed. These are broadly grouped into:

1) Intensive: these have deep, fertile soil and the planting (perhaps even including trees) is very similar to that in a ground-level garden – in fact, they are more usually described as a roof garden. They require a very high level of maintenance, just as would a ground-level garden, and don’t offer much in the way of additional ecological benefit since the planting & habitat is so similar;

2) Extensive: these have relatively thin substrates – typically from 50mm (2”) to 200mm (8”) thickness and are deliberately of low fertility. In this way they provide very different conditions to ground-level gardens and are colonised by very different plants – mainly low-growing, drought-tolerant, nectar-rich flowering species, often & ideally native, which gives food & habitat to a wide range of insects & invertebrates, and the birds which feed on them. They are very low maintenance, and this form is what is normally meant by “green roof”;

3) Semi-intensive: refers to a compromise between these two extremes, where varying conditions are provided across the extent of a (reasonably large) roof space, such that a mix of habitat and planting can be used – even including food crops.

Where would an extensive green roof be used?

Around the home - on free-standing structures such as sheds, garages, summerhouses, garden offices, fuel tanks & bunkers, etc. or on parts of the main building such as flat-roofed houses or extensions to them;

At schools - they could be used on similar building structures, or for cycle shelters and outdoor shelters or classrooms, perhaps associated with school crop or wildlife gardens;

In Streets - they could be used for street furniture like bus stations and shelters, train platform covers, electricity sub-station roofs and so on;

For commercial properties - they could be used over factory units and warehousing, supermarkets and their trolley parks ... the list is endless!

You can find out more by visiting

Wednesday, 11 November 2009

Residential Garden Design with Vectorworks Landmark

“Residential Garden Design with Vectorworks Landmark”
by Tamsin Slatter

This is a great book! Or, perhaps, I should say “a great manual” since I don’t suppose there are too many sad people like me who would take it to bed to read!

For anyone completely unfamiliar with “Vectorworks” here’s a brief bit of background. When I first started out from my college Garden Design course, I tried out several of the very cheap “design your own garden” programs before giving up and returning (literally) to my drawing board. I’m not saying that these programs don’t have their place – but that isn’t in the toolkit of a professional designer. A couple of years ago, I looked again at professional-level CAD packages and decided that, for me, Vectorworks looked the best and that it would be a worthwhile investment for my business. I opted for the “Landmark” and “Renderworks” components, in addition to Vectorworks itself (there are other components specifically for Interior Design, Architecture, Engineering and so on), which together provide huge capability – but, unsurprisingly, with a huge learning curve to become truly proficient and efficient in their usage.

I took a 20-hour training course and, after an initial delay due to other work commitments, started to use the package for my design work. With practice, I got fairly good at drawing up my surveys, working up concept plans, hard landscape construction drawings and soft landscape planting plans. What I hadn’t got to grips with, because it seemed too difficult, was using the 3D modelling capabilities – hence I was not making use of Renderworks, nor offering my clients the benefit of 3D views, with lighting and shadow shown at different times of day, or seasons of the year. Instead, I resorted to separate hand-drawn sketches or simple Google Sketchup models. This also meant that I was putting in extra effort developing isolated section views of construction drawings in addition to the plan views and the hand-drawn sketches.
That’s where this book comes in!
Tamsin prepared this book for Nemetschek, the developers of Vectorworks. She has excellent credentials for this – 20 years working for IT software companies before retraining as a garden/landscape designer, learning to make best use of the Vectorworks CAD system and becoming a renowned trainer and the UK’s leading expert in the software. In addition to this expertise, she has a personality, which really comes across in the friendly “sitting next to Nellie” style of this book.

So why’s it so good?

Firstly, the concept: It’s a project-based workbook which takes you on a journey from when you first, excitedly, fire up Vectorworks after installing it on your machine, into how it looks & feels, how to set up an efficient & effective “virtual drawing board”, and into the design workflow based on a sample project. This goes right from bringing in a survey file or drawing up your own survey data, through developing a draft plan, creating the 3D hardscape features, adding lighting (both daytime sunlight and nightscape artificial lights), creating planting schemes with varying levels of detail, to end up with hardcopy of plans, perspective views, materials and plant schedules – the lot!

Secondly, the practicalities: The book itself is convenient A5 size, and spiral-bound, so it lays flat within a very small footprint on your desk, or even held in one hand, while guiding your mouse with the other. It includes colour screen images or sections of them throughout, which are well-positioned to match the text. There’s a CD which holds both a PDF copy of the book and a set of Vectorworks files which constitute the sample project at various stages within the workflow and exercise files so that you can try things out without screwing up the project files.

After completing this book and project, the 3D features of Vectorworks/Landmark are completely de-mystified and just make sense as the natural way of working with the package – I found that I could easily work through my current design project alongside the book’s sample project and gain all the benefits and efficiencies which I’d been missing out on. I’m not saying that the supplied Vectorworks manuals aren't useful, but they are descriptive of what the various tools do, not how they are applied, and they seem to be written by “techies” not practitioners – which left me using only a fraction of the package in the 12-months-plus which I’d employed it. Not any more!

I do have some criticisms – there are a lot of “typos” which a better proof-reading should have found, though usually these don’t impact on comprehension. The screen-image clips are very small – presumably to keep the physical size of the book down – which is fine if you’re just using them as a visual cue to what you’re seeing on your screen as you work through the project, but sometimes they make using the book for reference difficult - unless you have much more acute vision than me.

My major criticism is that the book has no index, so to use it for reference you either have to thumb through the contents pages, which list topics within the workflow of the sample project, and then skip-read through that section; or you have to resort to the PDF copy and use Adobe reader’s “find” facilities to locate the item you need. The sample project is “split-level”, so the book does cover retaining walls, steps, raised beds and so on, but it doesn’t cover site modelling of a “real” situation where there are undulating contours and how to construct a design over this. Nor does it discuss “real” hardscape which has a rainwater run-off gradient. Perhaps these might be the subject of a future “advanced” landscape design book.


Would I recommend this book? Wholeheartedly and without reservation!

Who would benefit from this book? Students of Garden Design or experienced designers who are new to Vectorworks, and those people, like me, who are experienced users of Vectorworks but who’ve shied away from some of the most productive parts of the package because they seemed “too difficult”.

One final word of caution – make sure you have the appropriate version of the Vectorworks software - the book is for Vectorworks 2009, so you can’t read the exercise and sample project files if you’re running Vectorworks 2008 or below, though you could possibly manage with a 2009 demo version on another machine. If you’re lucky enough to have Vectorworks 2010, it should work OK, but I presume there’s a revision or new edition coming along to pick up on the enhanced 2010 features.

Steve Rice, Blooming Good Gardens, Southampton, UK

Friday, 6 November 2009

Garden Therapy

A survey by the National Trust showed that 70% of the population think that spending time in their gardens is important for their quality of life. Certainly, it seems, horticultural therapy is widely being accepted as an aid for people with many differing needs. A book edited by Simpson and Strauss discusses the healing potential of horticultural therapy as used by health professionals for a wide range of problems - physical disabilities, brain injuries, mental health issues.

Last year I visited a project in Southampton, The Mayfield Nursery, which offers a working environment for people suffering mental health problems. They raise and supply a good range of plants for sale, and also have special events throughout the year.

The Minstead Training Project is part of a charitable organisation which provides horticultural training and residential care for young people with learning difficulties at Furzey Gardens. The project offers training in work and social skills through horticulture.

The Normandy Community Therapy Garden aims to “share the joy of practical horticulture with people of all ages especially those who have any form of disability or learning difficulty.” They are a small charity, serving the areas of Guildford, Mytchett, Farnborough, Camberley, Woking, Farnham and Godalming.

Thrive is a charity which champions the use of gardening to change the lives of people with disabilities, whether rebuilding a person’s strength after an accident or illness, or providing a purpose for people coping with difficulty in their lives. They have one project in Reading, Berkshire, and one in Battersea Park, London, as well as supporting around 900 other gardening projects around the country. Thrive has launched its Green Circle project in Hampshire, which raises awareness of the importance of older people being able to continue gardening, and provides information and advice on how they can do this.

If you’re interest in colour therapy in the garden try here where Jill Crooks gives some design advice for creating moods through colour – exciting the senses, inspiring your day, creating tranquillity, brightening shady corners, symbolism of colour. She cites Gay Search’s book “The Healing Garden” (BBC Books, 2001).

The Institute of Horticulture Newsletter November 2009 gives details of some research by Plants for People showing that planting in any setting can increase happiness and decrease stress, as well as creating a fresher environment in which to live, suggesting that businesses as well as homes can benefit from interior landscaping, with employees becoming more productive and less likely to be absent through minor illness when plants are present in the office. Some of the earliest work on the use of plants for improving indoor environments was done by NASA back in the 80s, by the way.

Thank goodness the importance of gardens (and the activity of gardening) to our own health and well-being, as well as that of the wildlife that we share them with, is becoming more widely understood.

Monday, 2 November 2009

Those DM twitter Spammers

I’m pretty much a newcomer to the social media platforms, but I’ve noticed a recent spate of twitter users (“tweeple”) whose accounts seem to have been hijacked and used by persons unknown to send out tweets in the hacked person’s name. These are sent as direct messages (DMs) to the followers of the hacked account and include a hyperlink to direct you to a particular website.

Once they’ve become aware of it, the owners of the hacked accounts have sent out warnings that the DMs are not from them, and not to open the link. I don’t know if the link genuinely takes you to something interesting, or to a malicious website complete with viral attack software – I’ve been trying not to “fall for it” so haven’t followed the link.

How can your account get hacked? I’m not an IT specialist, nor a “hacker”, so I don’t really know, but I wondered if it was another example of phishing like those which are commonly used to try to get you to reveal online banking passwords - you know, the ones that say they’re the security department of the bank or building society, complete with a copy of their logo / branding, and try to get you to “confirm” your details.

It seems to me that the “new follower” notification from twitter would be a good candidate for a phishing scam. It could work like this:

1. You receive what looks like a new follower email notification, but which is really a cloned copy.
2. You click on any of the hyperlinks (new followers name or avatar, etc.) and this takes you not to twitter, but to the malicious site.
3. The malicious site then presents a clone of the twitter sign-in panel; if you’re unsuspecting you enter your account name & password – bingo they’ve got you!
4. The hackers can then use your twitter account to send the scam messages from your account to your followers. They use DMs since these are private and don’t appear on your timeline – so you’re less likely to spot that your account has been used.

This may not be how it works (maybe someone could comment to tell me?), but the precaution which I take, as with any other email that has direct hyperlinks, is to be suspicious! If you hover your mouse over the links, your browser will usually show where the link will take you – and if it doesn’t seem right, don’t follow it. For the twitter “new-follower” message I always go to the person’s profile from my twitter home screen, not from the email link, so I can’t be misdirected to a bogus website.

Apologies for straying off my usual garden / design topics, normal service will resume on next post!