Surface water run-off from roofs presents the eco-designer with some problems – but as we all know – problems provide us with opportunities for improvement. Green roofs are well known solutions to slowing down and reducing the amount of rainfall that eventually finds its way back into our groundwater. There is an alternative to this approach ...

THE BLUE ROOF:              The blue roof avoids the necessity for heavy planting materials as required by the green roof, by simply storing excess rainwater in rooftop gullies, channels or gutters. This water is released using flow control devices and can be used for almost any non-drinkable purpose. It can be released to a stormwater harvesting system for later reuse as well as an infiltration system that recharges groundwater, or released slowly as in the SUDs solutions discussed in previous blogs. The blue roof can therefore reduce the costs of installing a traditional drainage system and can replace – or be used together with a lower-capacity SUDs * system. The ratio of captured/discharged runoff is designed to closely mimic the pre-construction hydrology of the site.

APPLICATIONS:                 The easiest opportunity for using a blue roof occurs in a long, flat roofing style normally seen in commercial development. These roofs typically have wide gutters and a good watertight liner. Blue roofs work especially well in highly urbanized areas where there is less space on the site for stormwater detention or where large, highly impervious areas generate a rapid rate of stormwater runoff that can overwhelm drainage systems and cause flooding.  The blue roof can also be used on domestic buildings if planned in advance – and it can solve the old problem of how to get rainwater back up to a level where it will provide gravitational flow to its end-use system.

IS IT SUITABLE FOR YOUR SITE?        Sustainable building design isn’t about which method is better than the other -- it’s about how we consider all the alternatives in any given situation. There are many projects where a blue roof design could benefit both the environment and the client’s requirements. As always – get professional advice early on in the design stage of your project if you want to consider any unusual or inventive eco-building solutions.

* SUDs - please see previous blogs

Water and Suds.

 “Water levels in our rivers are down by 80% during low water conditions in comparison with 100 years ago” This comment which was made by an angler was discussed in a Foyle Angling Report (http://www.loughs-agency.org/angling/angling_reports

Various reasons were cited as causing this, such as major changes in land use, urban development, drainage, forestry on upper catchments, loss of the ‘sponge effect’ and water abstraction. Among the solutions discussed to combat this was the concept of ‘SUDS’. The comment on low water interests me because I have designed some SUDS solutions for surface water drainage on some new developments recently. Regarding the waterways in our area I can only say that years of agricultural (grant aided) drainage schemes have totally ruined them. I suppose there are other factors involved, such as pollution etc, but I can remember as a boy seeing large salmon taken from our local burn which is only a few feet wide. Then the Water Board (as the Rivers Agency was then known) came along and dredged out the local river and its tributaries and that was the last we saw of salmon (or brown trout for that matter) in our small streams.

SUDS:                       ‘SUDS’ is an acronym for ‘Sustainable Drainage Systems’ or ‘Sustainable Urban Drainage Systems’. Either way, it describes a means of reducing the environmental impact due to surface water run-off from the built environment. There are many ways to slow down, attenuate and filter the water that runs off our roofs, driveways, pavements and roads. By doing this we hold water upstream for longer periods and thereby reduce flooding in downstream, low-lying areas. There are other important environmental benefits and these can be read in further detail at http://www.ciria.org/suds/ .

SOLUTIONS:           I would like to see the Planning Service adopt the principle of SUDS as mandatory for ALL new development including single houses, renovation works and commercial sites, etc. I would hasten to point out that the cost of a well designed SUDS solution can often be much less than that of a conventional surface water drainage system.

To take the idea a stage further, we can often easily incorporate SUDS along with a pond, marshy wetland or bog garden in a suitable corner of our site, and attract some interesting wildlife in the process. Other solutions can include reed beds for effluent treatment, re-cycling ‘grey’ water and using water butts for watering the garden or washing the car (using natural detergents of course).

By using our water wisely before we drain it away, we reduce the load on our fresh water reservoirs.

By the way, who thinks that imposing water charges will encourage the average householder to conserve fresh mains water? – but of course that’s another debate entirely. As usual, feel free to comment below ...

One of the nine categories of the new Code for Sustainable Homes (see www.communities.gov.uk) is that of the level of water use. Even if the Code does not apply to where you live, it is a good step towards achieving sustainable houses and it is worthwhile to have a look at what it covers.

Apart from the moral environmental sustainability issues of water conservation, the proposals for water metering (i.e. pay-for-use) will provide additional incentives for us to reduce the amount of water we use. Water usage between similar house and family sizes can vary significantly, so the water usage calculator at http://www.taptips.ie/water-usage-calculator.htm is a useful tool for you to obtain an idea of how much water is used in your household.

Water Efficient Products    A wide range of products now exist to diminish our hitherto wasteful use of water in the home. We can install low-capacity W.C. cisterns and baths, shower restrictors to lessen water flow, efficient water taps, and water regulators.

Other solutions are also available; a urinal for instance is an excellent water-saving (and hygiene) feature in a household with a few male occupants and an aerating shower head will use much less water than a ‘power shower’ and will still give a refreshing effect. A useful guide to water efficient products is to be found at www.water-efficiencylabel.org.uk - and view the Products directory. Their ‘Top Twenty Tips’ for saving water in the bathroom also gives good commonsense advice.

Appliances          Water consumption information is usually listed separately from the energy efficiency labels on all new washing machines, dishwashers and driers, etc. Guidance on this is to be found at http://www.environment-agency.gov.uk/static/documents/Leisure/cwb_ch4_appliances_880694.pdf

Re-using building materials can be as simple as visiting a salvage yard - or more complex such as targeting a specific building that is to be demolished and taking as much out of it as is possible to re-use.

What Can You Re-use or Re-cycle?

• Concrete, concrete blocks and concrete bricks, etc can be crushed and used as aggregate for hardcore fill. Some contractors now produce this material from their demolition works.
• Blocks and bricks can be re-used to build walls if all the old mortar & plaster is knocked off them. This is a very labour-intensive process and it is often better to use them where the jointing is not a visual or structural priority - such as in rustic garden walls, random paving or as kerbing around garden beds, etc.
• Much of the timber taken out of old buildings is re-usable (but check for infestation or rot), as are any materials that can be removed without damage such as slates & tiles, stone quoins, stone sills, flagstones, etc.
• Plumbing and electrical fittings can often be easily refurbished for re-use – as long as they meet current regs.
• A new building can easily be designed to accept 2nd-hand windows, doors, fitted furniture and other joinery. Glazing units will need to achieve the minimum standards for thermal insulation – so check this before you buy! Fire doors will need certificates to satisfy building regulations.
• Cladding (steel or aluminium, etc) can be saved from old sheds and re-used in appropriate locations. Just make sure it can be successfully weather-proofed again.
• Structural items such as steel beams and columns are easy to re-use - but reinforced concrete is not so simple (although it can still prove useful). Structural calculations will be required before you use any of these.
• Heating equipment can also be re-used as long as it is serviceable, however many older installations might not possess the level of efficiency required for new building regs. Again, this is not a major problem if the old system can be left out of the calculations. An example of this is where a solid fuel stove or an old range could heat a conservatory which is not heated by the dwelling's system.

What Do You Avoid?

• Avoid materials which have been contaminated (oil, sewage, chemicals, etc).
• Avoid hazardous materials (asbestos, certain fibre products, lead products including paints, etc)

The answer to “What Can You Re-cycle or Re-use?” – is - almost all building materials!

This is a wide-ranging subject, and I will come back to it again in the near future.

As with all advice given on this website – always obtain professional advice that is specific to your particular situation – before you embark on your building project.

FIRST STEPS:

Rising energy prices and the slowdown in house sales have caused many to re-think their priorities. I have noticed a big rise in the number of people looking to improve their house instead of building a new one, and high on the list of discussion subjects is the question “What is the best way to reduce my heating bills?” No surprises there then!

ENVIRONMENT:                

Some statistics are in order at this stage: Nationally (for the UK), domestic housing emits about the same amount of CO₂ as road transport. Factor in the amount of emissions caused to manufacture the materials used to build the houses and we see that our homes are a source of more than half of the total CO₂ emissions. ‘Space heating’ is a term used to describe a system that heats (or cools) the spaces in a building, but when you think that about 53% of CO₂ emissions from homes are due to space heating systems, the term might also be considered as ‘heating space’ i.e. in the cosmological sense!

SOLUTIONS:                      

There is no single way to achieve energy efficiency, but preventing heat loss should always come before considering alternative energy sources. Just as some people have found a new diet that works for them, every house has a solution which gives the best improvement in performance for your money. Your house needs to be examined in detail to discover what needs to be done.

INITIAL APPROACH:        

Professional advice at the start can save time and money – OK I know I’m biased here - but I’m also right! Good advice will specify exactly what work is needed and what it will cost; and will not follow trends blindly or encourage you to buy new technology without first balancing the environmental benefits.

This first survey or examination can be as simple or as complex as you wish to make it – but I try to follow the old ‘KISS’ rule.

After assessing structural stability and weatherproofing, the two main points to address are:

1. Insulation – What if any, insulation exists? Add to it or replace it and bear in mind that building regulations are a basic standard and not the optimum specification. Think ‘outside the box’ if necessary.
2. Air Permeability – How badly does your house leak air? (Tests can be carried out if required.) Leaky points are not always obvious, and although some ventilation is required, it should be ‘controlled’ ventilation. Fix the unwanted leaks and consider if you really need that open fireplace!

This touches briefly on one aspect of eco-building. If your interests are in new build, good thermal performance is much easier to obtain.

I will discuss methods of achieving higher energy efficiency in future articles.

The ‘Zero Carbon’ concept for new buildings has been widely discussed. There is a growing realisation that new buildings will not be truly zero-carbon unless everything in the sourcing, processing, transportation, manufacturing, building and end-of-life processes have been achieved without producing carbon. As you can appreciate, although possible - this will take some considerable time to achieve. In the meantime it is easier to achieve a no-new-carbon building. For further ideas on achieving this, keep updated on these blogs. For answers to a particular question, please contact me.

Building energy efficient homes is important, but no system will work properly if the users abuse it. As an example, think about how many ‘computer problems’ are not really computer problems at all. Many of the trends of building usage over the last few decades have been going in a direction that must be reversed – higher indoor temperatures, whole house heating, a proliferation of new electronic appliances, some of great energy consumption and so on.

Energy Reduction…   

There are four distinct parts to the energy reduction in buildings:

1. An improved thermal & air-sealed envelope for buildings
2. More efficient appliances and building controls
3. Decarbonised sources of energy, whether from the grid or locally generated
4. Changes in personal attitudes and behaviour in respect of the profligate use of energy.

The first three are matters of engineering, and the last a matter of psychology and sociology. I believe that the last is as important on its own as the first three put together.

Carbon Reduction Policies

Apart for the well-known effects of dumping large quantities of carbon into the atmosphere, we currently consume renewable resources 30 per cent faster than the planet replenishes them.

The UK’s lead on climate-change policy is to be applauded but we are a long way from meeting our targets, along with various governments around the world who adopt (unworkable) piecemeal approaches to reducing greenhouse gas emissions. Proposals for zero-carbon buildings are over complicated with arbitrary ‘carbon compliance’ levels (which are not zero carbon) and ‘allowable solutions’ which are bureaucratic and unworkable.

Buildings & Lifestyle:                     Governments must encourage buildings that enable a new way of life – with access to local food, recycling facilities and no cars (at least in densely populated areas). Numerous sustainable communities have been set up to address this challenge. The ideal is not simply about constructing greener buildings, but enabling a way of life which reduces car dependence, provides easy access to local, seasonal food and makes recycling easy. Communal rooftop allotments, biomass boilers for CHP (Combined Heat & Power) on-site composters and community heating systems are all being deployed to tackle carbon reduction.

To achieve effective change, we need elegant solutions and a sensible systems-based approach to zero carbon; for example, recognising electricity as a pooled resource and maybe converting buildings into power stations. Effective land use is as critical as carbon emissions.

Action for Change:     Extensive research on the subject has convinced me that the only way to achieve targets is to tackle sustainability in a holistic way which integrates the built environment, transport and food provision. Buildings are only part of the solution; places and lifestyle are just as important. We as individuals and groups must show governments that we want the changes and governments must provide the incentives for the changes to happen. We can not only express our desire for a healthy planet through our actions, but also by letting the decision makers know what we want.

It is still not too late to let your voice be heard on the forthcoming

UN Climate Change Conference in Copenhagen

(Dec 7^th to Dec 18^th 2009) 

just go to http://www.1010.ie/ and http://www.actoncopenhagen.decc.gov.uk/en/subscribe

Recommended Booklist

Recently, I have been reading various inspirational books on how a low-carbon, energy efficient planet can be achieved. The important thing to realise is that change is already happening at a much faster rate than previously thought possible. ‘Plan B 4.0’ from Lester R. Brown’s ‘Plan B’ series of books quotes environmentalist Paul Hawken in a 2009 college commencement address. In recognizing the enormity of the challenge facing us, he said: “First we need to decide what needs to be done. Then we do it. And then we ask if it is possible.” Download the book as a free e-book or buy it at http://www.earthpolicy.org/index.php?/books/pb4

Globally, the Transition Towns network (which began in Ireland) is growing rapidly. It is not a ‘we are doomed’ movement but a brilliant concept of how groups and communities can get together to create change and work towards a green, healthy future. The name is perhaps misleading because ‘towns’ is not what it is all about – communities in places ranging from small rural areas to large cities are all involved. Rather then reading my version – have a look at http://www.transitionstowns.org and http://transitionculture.org

For an in-depth of the concepts behind the network, read Rob Hopkin’s book ‘The Transition Handbook’, and as background to that – read Richard Heinberg’s book ‘Peak Everything’. You should be able to borrow them from your library. Finally, to get involved in your local network – check out http://transitiontownsireland.ning.com

Public awareness is growing all the time of the urgency of the need to tackle climate change.  Scientists are telling us that we must achieve an 80% reduction in carbon dioxide emissions by 2050, and in the recent Budget the Chancellor committed the UK to the world’s first carbon budgets which fix binding limits on greenhouse gas emissions over five-year periods, including carbon dioxide reductions of 34% by 2020. 

What Does This Mean?…     As a recent energy report pointed out, if we are to meet our carbon targets, virtually all 24 million existing buildings in the UK would need converted to reduce their carbon emissions by that sort of amount, and to do that job over the next 40 years we would need to refurbish an entire city the size of Cambridge every month.  That’s about 23,000 teams of people working on each building for a two week period and keeping that rate of refurbishment going non-stop for the next 500 months.

But is this truly sustainable development? How much carbon will be released if we go on using current / dated building methods during the refurbishment programme above? The answers lie in using green construction methods, materials and processes.

Any Comments? Add them below.