(what is this?)

(For Google Reader and iGoogle users)

Welcome to the NHER's Zero Carbon Blog.

Let me introduce myself. I'm Heather Stamp and my new role within the NHER is Zero Carbon R&D Manager. The industry is agreed that moving to zero carbon within the timeframe is going to be tough. From my initial investigations it is clear that we do have the capability to reach the 2016 goal, but we must draw on lessons learnt from the UK, Europe and beyond if we are to accelerate our learning.

The NHER is committed to supporting the move to zero carbon, and currently see that the main barrier is the gathering and dissemination of knowledge. To bring information together for this webpage I will be attending events, presenting case studies, and talking to people involved in low carbon developments - sharing the theory and practical experiences, problems and successes.

28 November 2007
Code for Sustainable Homes outputs from Plan Assessor

In Plan Assessor v3.1 there is an amended and expanded CSH report:

• Code Level 6 calculation - The algorithms for the calculation of carbon dioxide emissions due to cooking and appliances have been amended to be in line with the latest version of the Code Technical Guide (October 2007)
• Item Ene 3 has been added to the report to assign the credits for Internal Lighting
• The credits assigned to Ene 2 Heat Loss Parameter have been bug fixed

We still plan to expand this report to produce an output for Ene 7 in future versions of the software.

For reference the October version of the Technical guide for the Code can be found by clicking here.

22 October 2007
Low Carbon Case Study - Tree House

NHER Low Carbon Case Studies are real-life examples of low carbon homes that can serve as examples of what is achievable. Some will be one-offs, some will involve extensive refurbishment, but all demonstrate large carbon savings, going beyond the minimum required by regulations.

Examples of this nature are vital if we are to really understand what is possible in the real world. We need to share experiences, good and bad, to prompt debate and to inform design decisions on the road to 2016.

More case studies are needed to spread the word… If you are working on a low carbon development then please do get in touch. Your project could be become an NHER low carbon case study!

To see the case study, click here.

23 July 2007
The Future of the Code For Sustainable Homes

The consultation 'The future of the Code for Sustainable Homes – making a rating mandatory' on proposals to make the Code mandatory has been published on the CLG website. Click on the image below to access it.

The consultation seeks views on:

• Making a rating against the Code mandatory for new homes
• The connection between the Code and EPCs
• Using HIPs as the mechanism for communicating Code rating to homebuyers
• When to update the Code
• Future content of the Code, including the introduction of minimum standards for Liftime Homes

Closing date for responses is 23 October 2007.

2 July 2007
DTI Low Carbon Buildings Programme

The Low Carbon Buildings Programme replaced the DTI Clear Skies grant programme for existing homes some time ago, but they have some clear guidance for adopting appropriate micro-generation technologies (generally also applicable to new-build) and they offer the following advice…

PV:

You can use PV systems for a building with a roof or wall that faces within 90 degrees of south, as long as no other buildings or large trees overshadow it. If the roof surface is in shadow for parts of the day, the output of the system decreases.

Solar panels are not light and the roof must be strong enough to take their weight, especially if the panel is placed on top of existing tiles.

Biomass:

You should consider the following issues if you're thinking about a biomass boiler or stove. An accredited installer will be able to provide more detailed advice.

• Fuel: It's important to have storage space for the fuel, appropriate access to the boiler for loading and a local fuel supplier.
• Flue: The vent material must be specifically designed for wood fuel appliances and there must be sufficient air movement for proper operation of the stove. Chimneys can be fitted with a lined flue.
• Regulations: The installation must comply with all safety and building regulations (see Part J of the Building Regulations).
• Smokeless zone: Wood can only be burnt on exempted appliances, under the Clean Air Act. This mainly applies to domestic appliances.
• Planning: If the building is listed or in an area of outstanding natural beauty (AONB), then you will need to check with your Local Authority Planning Department before a flue is fitted.

Wind turbines:

Wind speed increases with height so it's best to have the turbine high on a mast or tower. Generally speaking the ideal siting is a smooth-top hill with a flat, clear exposure, free from excessive turbulence and obstructions such as large trees, houses or other buildings.

Small-scale building-integrated wind turbines suitable for urban locations are also available to install in homes and other buildings.

But… electricity generated at any one time by a wind turbine is highly dependent on the speed and direction of the wind. The windspeed itself is dependent on a number of factors, such as location within the UK, height of the turbine above ground level and nearby obstructions. If you are considering a domestic building mounted installation and electricity generation is your main motivation, then the guidance is that you only consider a wind turbine under the following circumstances:

• The local annual average windspeed is 6 m/s or more. An approximate figure for your location can be checked on the DTI website.
• There are no significant nearby obstacles such as buildings, trees or hills that are likely to reduce the windspeed or increase turbulence.

For more information from the LCBP on micro renewables see:
http://www.lowcarbonbuildings.org.uk/micro

7 June 2007
Analysis of Consultation Responses

CLG have now placed the analysis report for the Consultation 'Building a Greener Future: Towards Zero Carbon Development' on their website - click here to read it.

Some points of interest:

Qn2: It is clear that at the time of the consultation nobody really knew what the cost implications of the Code would be.

Qn4: Consultees mentioned a whole host of other areas that policy should be addressing to tackle climate change.

Qn7: 61% of consultees supported the proposal of all new homes being assessed under the CSH.

Qn8: More than half respondents believed that the 2016 timescale was achievable, subject to education and technological developments. However, this was in contrast to the developers (half of them believed timescales were not achievable).

23 May 2007
All Energy '07 (Aberdeen)

This renewables conference (the 7th year of the event) was eye-opening - offering a chance to study all the latest renewable generation innovations in on place. With 4000 visitors compared with 2850 last year and over 350 exhibiting companies, there was plenty to discuss.

Wind (on- and off-shore), wave, tidal, hydro, hydrogen and fuel cells, solar and biofuels were all represented.

As the day wore on I set myself the challenge of sourcing smaller biomass boilers – I had noticed that the vast majority on show were far too large for the heat demands of low carbon dwellings (on an individual basis at least, but the other side of the coin is obviously shared boiler schemes). I wasn’t too successful in my quest, but I did manage to find an interesting room heater/wood pellet boiler hybrid but it was still in final product testing.

But it wasn’t just all talk and presentations; there were technical tours to a wind farm and biogas plant, both fully operational. The trips received good feedback from the people I met that had attended, and I hope there are more of these visits next year.

The conference covers all aspects of renewables, so to drill down to the micro-level of scheme that could be designed to supply a small site or single dwelling was a challenge. The future for larger scale renewable projects seems rosy, there was a very positive air at the conference that barriers to/perceptions of the technologies were changing. In contrast, micro-generation still seems to be suffering from performance and installation issues at the moment, and this just made me realise how important the role of off-site generation will be in helping us achieve 2016.

The website is still active and dates for next year are already set, so read all about it here.

17 May 2007
Environmentally beneficial nanotechnologies

And now for something completely different…

This is a short entry to link to something more blue-sky and far reaching than your immediate concerns over the practicalities of constructing low/zero carbon housing - but some of you might find the time to digest something slightly off-beat.

Defra has commissioned research into the opportunities and potential obstacles to adopting particular nanotechnologies for use in these areas: insulation, photovoltaics, electricity storage, engine efficiency (fuel additives) and the hydrogen economy.

In this context nanotechnology refers to the use of materials at the molecular and atomic level to bring environmental benefit. The report is available in pdf format by clicking here.

14 May 2007
The EQuilibrium Challenge

The Canda Mortgage and Housing Corporation (CMHC) is leading a national design and demonstration initiative called 'EQuilibrium Housing', bringing together the private and public sectors to develop zero-impact sustainable homes in communities across Canda.

EQuilibrium Housing state: "Faced with rising energy costs, a greater concern for the environment and an incressed focus on the health of their families, more and more Candians are looking for housing options that are healthy, energy-efficient, environmentally friendly and less expensive to operate and maintain."

EQuilibrium Housing considers the five key principles for sustainable design as Health, Energy, Resources, Environment and Affordability.

12 EQuilibrium demonstration process have now been selected. Construction will soon begin and the progress of the sites can be tracked online.

More info on EQuilibrium and the 12 demonstration projects can be found by clicking here.

28 April 2007
English Partnerships assess the cost of achieving new CSH levels

English Partnerships and the Housing Corporation have adopted Level 3 of the Code as the minimum standard for all newbuilds. Researchers at Cyril Sweett found that the additional costs involved in achieving Code Level 3 of the CSH will be around 3% more than the previous standard of EcoHomes 'Very Good' although it could be as low as 0.4% for some dwellings and as much as 6.2% for others.

You can find the English Partnerships press release by clicking here. Click on the image below to read the cost review.

26 April 2007
Zero Carbon Housing - Ibis Hotel, London

This conference run by Construction News was endorsed by the Construction Products Association (CPA).

John Tebbit (CPA) firmly believes that the key to building zero carbon dwellings that perform in the real world is workmanship. 'Design the details' so that joints can be reliably constructed onsite and will perform as they have been designed.

He then urged planning authorities to accept a variety of solutions for zero carbon housing, and not to go about inventing their own set of rules for their area. Building zero carbon homes to the zero carbon definition is enough of a challenge to the industry without being presented with different goalposts in different areas of the country.

The public "just want their house to work" so control systems must be "designed for human beings, not geeks!"

Lastly he said that there are examples out there, and we need to study them and understand what worked and more importantly, what didn’t work.

The CPA website can be viewed at http://www.constprod.org.uk/

Following a "keep things simple" approach, Andy Von Bradsky (PRP Architects) urged the industry to "build long term energy efficiency into the design" for example building south facing roofs at optimum pitch for retro-fitting PV or solar thermal at a later stage. He recognised that the last 20% of carbon is currently very expensive to displace.

He described 3 prioritised steps for low carbon design:

1. Energy efficient construction – Good fabric insulation, super insulation, building airtightness and controlled ventilation
2. Passive design solutions – Orientation, large glazed areas facing south, passive ventilation and low water usage
3. High technology solutions – Renewables, mechanical ventilation with heat recovery and combined heat and power

Incidentally, PRP have also won the Architectural Practice of the Year Award at the Building Awards 2007.

Overviews of projects can be viewed in the Sustainability category of their website.

Michael Shwartz (Zedhomes) explained that he had found the different approaches by different local authorities very difficult to work with and plan for (similar solutions could be seen as ideal or totally unacceptable depending on the planning approach in the area).

Particular interesting is the Harrow ZED development which is zero energy, but looks identical to the traditional development next door – proving that low and zero carbon homes don’t have to be out of place with what we think of as traditional British designs. He estimated that the public are willing to pay 10-15% more to buy into developments such as Harrow ZED.

He believes we should embrace new technologies – by starting small economies of scale with follow.

On a different note, he warned that in fact it will be water (not energy or carbon emissions) that will become the biggest challenge in the South East of England in the coming years.

The Zedhomes website has a section of Zero (Fossil) Energy developments.

11 April 2007
Technical Guide for the Code for Sustainable Homes published

The Technical Guide can be found on the Planning Portal website by clicking here. The guide explains how the CSH is calculated from credits under each category. These are then converted to points per category by applying an environmental weighting, before being converted again into a Code Level. The guide also contains a definition of a True Zero Carbon Dwelling (Page 29) to achieve Code Level 6.

A True Zero Carbon Dwelling is one where the net carbon emissions resulting from ALL energy use is zero. This is to be shown through the SAP calculation and includes:

• Space heating/cooling
• Hot water
• Ventilation
• Internal lighting
• Cooking*
• All electrical appliances*

The contribution from renewables can be included provided that:

• Renewable or low carbon technologies are installed on/in the dwelling
• Provided by an ESCO (Energy Services Company) on or off site (but only if it directly supplies the dwelling)
• Estimate from Accredited external renewables** (NB some ESCOs offer these)
• Heat Loss Parameter must be shown to be no more than 0.8W/m²K
• Heat and power (individual dwelling or community heating) must not be fossil fuelled

* This will be calculated by a later revision of SAP, in the interim, a procedure has been published in the Guidance document.
** These are offsite renewables which are accredited under the Energy Act 2004 (i.e. Renewable Energy Guarantee of origin (REGO) Certified) OR new installed capacity designed specifically to meet the loads of the dwelling OR are additional to capacity already required under the Renewables Obligation.

22 March 2007
What can we learn from the Canadians?
The House that Bjorn built, Towards a zero carbon home - British Library, London

He presented some key lessons from Canada's 'house as a system' approach, considering interactions between constructional elements, technology and behaviour:

1. It is essential to translate technical features into tangible benefits that motivate homeowners.
2. Careful application of passive solar design with attention to summer overheating, shading and ventilation.
3. Increased insulation levels should be accompanied by a major reduction in air leakage.
4. Minimise air leakage by developing clear construction details and test for buildability so that builders do not need to improvise on site.
5. Training, explain what to do but more importantly why to do it.
6. Check products for verified performance.
7. Test every house for air leakage to check that the design is being carried successfully into the build.
8. Avoid natural draught combustion equipment because of low efficiency and health and safety concerns.
9. Improve air quality by sourcing finishes that emit fewer contaminants.
10. Use continuous mechanical ventilation with heat recovery 'build tight, ventilate right'

He also gave some indication of what a Net Zero Energy Healthy Home will look like:

1. Very high levels of insulation – average U-value of 0.11 for walls and 0.09 for ceilings.
2. High performance windows – The weak link in the building envelope, will need to be triple of quad glazing in fibreglass frames (the extra steel reinforcement required in uPVC frames would cause to much additional thermal bridging loss). Warm edge spacers need to be low conductivity such as silicon or foam and units should be gas filled and have good low-e coatings (different coatings can have very different performance). To take advantage of solar gain it can be useful to install windows of different specifications on different orientations.
3. Aggressive targets for minimising air leakage – to as low as 0.5 air changes per hour. Canadian experience is that we should not be discussing 'air permeability' as they deem any loss of heat in this way as unwanted 'air leakage' to be minimised.
4. Mechanical ventilation with heat recovery – two units set in-line with efficiency of 70%, equals 70% of heat recovered followed by 70% of the remaining 30% = 91% of heat recovered.
5. Passive solar heating and cooling, often with added mass.
6. Renewable energy systems – including solar domestic hot water system, approx 5.5kWp of PV, ground source heat pumps (although these are not always suitable for very low demand houses).
7. Drainwater heat recovery – pre-heating incoming water supply can save up to 20% of water heating load.
8. Daylighting techniques.
9. Very energy efficient lighting and appliances.
10. Whole house kill-switch to minimise stand-by power loss (taken from technologies used in hotel industry).
11. Advanced metering – ensure energy use is visible to occupants.
12. Healthy housing materials and finishes – higher internal air quality.
13. Building materials with lower embodied energy e.g. timber frame, cellulose insulation etc).
14. Water conservation and re-use.

This blog will be updated will all the latest news on low and zero carbon development. If you would like to contribute, don't hesitate to email me.