Japanese knotweed and the impact on development

Thomas Williams

It is important that Knotweed is identified on site early; the cost for controlling the plant at the London Olympic Village is estimated to be £70m and in 2010, according to CABI, the annual cost to British Development sites was £150m.

Getting advice quickly can:

• Reduce excessive costs for destroying, disposing or managing knotweed
• Avoid potential prosecution and/or compensation claims
• Prevent further damage to the physical fabric of the building and other hard surfaces
• Provide a better environment

There are many different types of knotweed, such as Giant, Bohemica or Hybrid, Himalayan, Lesser and Japanese. It is a non-native invasive species of plant and has the following identifying factors:

• Mid- green leaf, shield-shaped, varying size
• Leaf stem has distinctive zig-zag, is often pink/purple in colour
• Stem is bamboo-like, hollow and jointed and green, often with a pink/purple speckle
• Crown is a knotty mass often partially visible above ground
• Rhizome underground stem system can spread several metres in any direction, internally orange
• Flowers are small, white, five-petalled, appearing in late August, persisting until late October 

Once these plants move into a new environment they suddenly have none of these factors present and are free to grow and spread, causing significant damage to buildings and landscaping.

  

A variety of solutions are available, from chemical treatment to burial, and costs vary from £10-25+ per m2 with timescales of up to 36 months.

For more information get in touch or try:

• The Environment Agency “Knotweed code of practice” 2006
•  “Japanese Knotweed and Residential Property” RICS Information Paper 1st Edition 2012
• Environmental Protection (Duty of Care) Regulations 1991
• Environmental Protection Act 1990
• Wildlife and Countryside Act 1981

Don't waste the opportunity

Emma Nicholson
Last month the Government announced that Site Waste Management Plans would be scrapped, although they haven’t indicated when.

Isn’t this removal of legislation too soon for an industry still grasping how to improve its waste reduction targets on construction sites? Or has the legislation already done its job?

According to figures from the Constructing Excellence KPIs, construction waste has been cut by a third since the legislation came into place in 2008. What is the government’s intention here – simplification of procedures?  We’re going to have to wait for up to twelve months for an answer.

The DEFRA consultation states that “ministers do not believe these regulations are necessary... because they impose burdens that do not in reality help achieve environmental goals. Removing these regulations should result in a cost reduction for business/others.”

However, the importance of dealing with waste cannot be stressed highly enough. WRAP has encouraged companies to make substantial performance improvements and to prioritise waste reduction during design so that materials are used efficiently and cost savings can be achieved (Halving Waste to Landfill and Designing out Waste).

With uncertainty regarding the future of SWMP legislation, it should be noted that WRAP has also worked closely with LOCOG making pioneering strides with a zero waste policy and vision for the London 2012 Games.
 
This knowledge and insight must be retained by the industry. A number of experts and consultants have been involved in the Zero Waste Games Vision and it is something the whole industry should aspire to. 

For further information about the sustainability of the Games visit http://zerowasteevents.org/ or www.london2012.com/documents/sustainability/london-2012-zero-waste-events-protocol.pdf 

The Green Deal: Good news for RSLs, but concerns for public take-up

Lachlan Fulton 

The Government’s vision to have all practicable cavity walls and lofts, together with up to 1.5 million solid walls insulated by 2020 is dependent on the success of the Green Deal and Energy Company Obligation.

With this in mind, I recently visited The University of Salford’s “Energy House”, a facility performing tests on possible Green Deal energy conservation technologies, to discuss the potential barriers which could prevent the scheme from delivering the results needed.

Following a tour of the testing facility, a traditional pre 1920’s Victorian terrace house reconstructed in a lab, the conversation moved from technology to the market.

Although it appears Registered Social Landlords (RSLs) are positioning themselves well to take advantage of the scheme, there is a valid cause for concern that the public won’t be so keen to jump on board unless they are confident that they won’t get their fingers burnt.

Homeowner’s perceived value in a Green Deal intervention, the integrity and capability of Green Deal assessors and installers, and Green Deal charge repayments affecting saleability – are all key factors raised which could jeopardise the success of the Green Deal.

With the Green Deal targeted to be available in Autumn 2012, it will be interesting to see how things develop over the coming months.