Interpave has published another issue of its digital magazine e:Pave covering the latest developments in urban design, architecture, landscaping, sustainability and civil engineering – all with a paving focus. e:Pave takes over from Interpave's popular hardcopy magazine Pave-It.
Simply download this issue as a PDF file now and by registering you will be sure to receive future issues automatically via email. Back-issues of Pave-It can also be viewed here with a summary of articles covered in each issue.
IMPLEMENTING SUDS NOW
Implementation of new legislation to make sustainable drainage systems (SUDS) mandatory on all new developments is threatened with delays. But there is no reason why concrete block permeable paving, an established SUDS technique, cannot be used more extensively now to satisfy existing planning policies and other requirements.
The Draft Flood and Water Management Bill will apply to new surface water drainage from buildings and roads in England and Wales. The Bill is intended to replace current arrangements for approval, construction and maintenance of conventional piped drainage with similar procedures applying to SUDS techniques. A new set of National Standards is planned by 2011, developed in conjunction with trade associations and other stakeholders, to deal with the different SUDS techniques.
The Bill does, however, cover a much wider range of issues affecting flooding and water than just SUDS, many of which have raised concerns. The Commons environment, food and rural affairs committee recently warned the government that rushing the draft Bill would render it ineffective. It recommends delaying until after the general election to allow time for draft plans to be rethought – and putting the 2011 implementation date at risk.
So, how does this situation affect concrete block permeable paving? Without doubt, it is the most versatile SUDS technique - but it does differ from others, such as swales and other soft landscaping features. In particular, detailed guidance for design, construction and maintenance is already in place for concrete block permeable paving from Interpave, based on decades of experience both here and abroad, which should form the basis for National Standards.
There is therefore no reason why concrete block permeable paving should not be used more extensively now, in place of impermeable surfaces, gulleys and pipes, to meet existing planning policies and satisfy a range of sustainability criteria. It is worth remembering that current planning policies across the UK strongly prioritise SUDS and place responsibilities on local planning authorities to further their use. Building Regulations also already favour source control measures such as permeable paving. And the Code for Sustainable Homes and BREEAM assessment methods for other building types include various requirements which permeable paving satisfies.
SUSTAINABLE RESPONSE
The Draft Flood and Water Management Bill aims to make sustainable drainage systems (SUDS) mandatory on all new developments, with major potential for expanding the use of concrete block permeable paving. As part of the consultation process for the Draft Bill, Interpave has submitted a detailed response highlighting two particularly important considerations.
Firstly, as permeable paving us fundamentally unlike other SUDS techniques, National Standards related to the design, detailing, construction, maintenance and adoption of concrete block permeable paving should be developed in conjunction with Interpave and based on the existing Interpave Guide.Secondly, although most SUDS techniques fall outside the immediate highway area, permeable paving simply provides a sustainable alternative to conventional paving with its piped drainage, but on the same footprint. So, at adoption it will itself become the highway, along with impermeable areas draining onto it.
The limited maintenance requirements that apply to concrete block permeable paving, such as sweeping, are similar to those for conventional highways. It should, therefore, be treated similarly to conventional highways and associated drainage using Highways Act 1980, Section 38 adoption agreements with highway authorities. In any event, it is essential to remove any barriers to Section 38 adoption of concrete block permeable paving as a highway - as distinct from a drainage system as considered in the Draft Bill. To achieve this aim, it is recommended that the new National Standards also be applied to Highways Act Section 38 adoption.
Just as with conventionally paved areas, by applying correct details, design, specifications and guidance - all available from Interpave – developers, designers and adoption authorities can have confidence in the long-term performance and life span of concrete block permeable paving as an essential, mainstream technology.
Interpave’s detailed consultation response can be downloaded here.
SUDS MANDATORY WITHIN 2 YEARS
New draft legislation will make sustainable drainage systems (SUDS) mandatory on all new developments within 2 years, and use of concrete block permeable paving – the most versatile SUDS technique – is set to grow rapidly to satisfy this requirement.
The Draft Flood and Water Management Bill, issued for consultation on 21 April, will apply to new surface water drainage from buildings and roads in England and Wales. It takes on board many of the proposals of the Pitt Review into 2007 flooding events and the government’s Water Strategy for England, and aims to make SUDS happen on the ground, helping to avoid flooding and reduce water borne pollution.
In general terms, the Bill will replace current arrangements for approval, construction and maintenance of conventional piped drainage with similar procedures for SUDS. In particular, it expects that: “In new developments, permeable paving, swales or French drains should take the place of traditional impermeable roads and pavements draining to sewers.” Also, highway authority drainage must comply with the same standards - a new requirement that goes beyond the 2008 consultation proposals.
A new role for unitary and county authorities as ‘SUDS Approving Bodies’ (SABs) will be established and they will be required to adopt – i.e. take over ownership and maintenance of – SUDS schemes. At the same time, developers will be required to demonstrate compliance with National Standards and pay a financial bond to SABs, just as the current regime for conventional piped drainage. National Standards for construction and maintenance of SUDS systems will be developed with stakeholders by 2011.
But in the case of concrete block permeable paving, detailed guidance from Interpave is already in place, based on decades of experience both here and abroad. So, there is no reason to prevent concrete block permeable paving being used now in place of impermeable surfaces, gulleys and pipes – bearing in mind that current national planning policies already require SUDS and Building Regulations favour them. This initiative also opens up the market for concrete block paving generally on lower speed roads, shared surfaces and other areas where visual appeal, sustainability, accessibility and long-term performance are demanded.
NEW FRONT GARDEN RULES
Originally part of the government’s water strategy launched in February, new planning rules will apply in England from 1st October. They aim to encourage homeowners to use permeable paving, rain gardens and similar sustainable methods when installing new or replacing existing paving in front gardens.
Homeowners will no longer be allowed to pave their front gardens without planning permission - unless permeable surfaces such as concrete block permeable paving are used or water is otherwise able to soak into the ground, for example using rain gardens. Otherwise, planning permission will be required for hard surfaces over 5m2, involving drawings, application forms, a fee of £150 and around 8 weeks for a decision. And, of course, permission may well not be granted anyway.
These measures form part of the fight against flooding and move towards sustainable drainage systems. Interpave has already recognised the need to address this issue. Straightforward guidance is available to homeowners, garden designers, contractors and others involved in domestic paving, on sustainable drainage to avoid water discharge into sewers when using concrete block and flag paving for an attractive, safe and firm surface. It is important to remember that loose materials such as gravel do not meet Building Regulations requirements for safe access of disabled people to homes.
Concrete block permeable paving can be used to allow rainwater to filter through gaps between the blocks, and eventually into the ground or to drains. The same principle applies to conventional concrete block and flag paving installed to channel water into a ‘rain garden’ where the water has time to soak into the ground. Both methods are covered in the Interpave guidance which aims to provide a straightforward, step-by-step design procedure - based on design calculations using sound engineering principles – together with advice on construction and plants.
The government guidance stresses the importance of using experienced contractors and refers to trade associations including Interlay to find suitable companies. Further information >>
For paving contractors, the Hard Landscape Training Group is holding a series of courses in October and November on how to design and construct concrete block paving to meet the new planning rules. Further information >>
GREEN PAVING
The recently launched BRE ‘Green Guide to Specification’ provides independent endorsement of the low environmental impact of precast concrete paving, particularly in comparison with imported materials.
The Green Guide rates a wide range of elements from ‘A+’ for best environmental performance to ‘E’ for the worst. Three different paving scenarios are considered covering: Pedestrian Areas, including communal spaces, walkways and garden paving; Lightly Trafficked Areas, such as car parking; Heavily Trafficked Areas, for heavier vehicles or repetitive car traffic.
The summary environmental ratings for a range of precast concrete paving specifications – covering blocks, flags and ‘grass concrete’ units - are generally ‘A’ or ‘A+’ across all three scenarios. These ratings reflect the on-going environmental investments and improvements made by Interpave manufacturer members, as well as by the cement industry generally. Local material sourcing and product supply is also important, and equivalent paving products shipped into the country bear a substantial CO2 emission load. Some imported stone paving products are also included in the Green Guide – generally with much poorer environmental ratings than their precast concrete equivalents and half with the worst ‘E’ rating.
CUTTING
In response to concerns about the impact of dust generation resulting from cutting building materials on site, Interpave has produced guidance for precast concrete paving products following discussion with the Health and Safety Executive. Click here >>
PAVING TRAINING
A programme of training courses covering all aspects
of paving and hard landscaping is being run by The
Hard Landscaping Training Group, an initiative funded
by CITB and supported by industry. The paving programme,
which runs to the end of November, includes individual
courses covering setting-out and installation of
paving blocks, flags, kerbs and channels. Of particular
importance is the permeable paving course, with this
essential sustainable drainage technique rapidly
growing in popularity. For information on this latest
programme of courses, the HLTG and other training
visit: www.hardlandscapetraininggroup.co.uk
RESPONSIBLE
RAINWATER MANAGEMENT
Interpave’s new guide
offers straightforward information for home-owners,
designers and contractors on sustainable rainwater
management for domestic paving – such as
driveways, patios and paths. Two basic techniques
are covered: conventional precast paving draining
onto rain gardens and concrete block permeable
paving.Click here >
SUDS
LAW
With the recent publication
of the government’s PPS 25 Flooding guidelines,
a brand new Interpave brochure examines each of
the stages in development control to highlight
the clear requirements for SUDS - and hence Concrete
Block Permeable Pavements. Essential reading for
all those involved in planning and development. Click
here >
PERMEABLE
PAVEMENT DESIGN GUIDE UPDATED
Interpave’s definitive
technical document Permeable Pavements – guide
to the design, construction and maintenance of
concrete block permeable pavements, Edition 4 has
now been published and is available to download.
It provides comprehensive and detailed information
for planners, designers, engineers and other decision
makers.
Click
here >
MMC
AND MODERN METHODS OF PAVING
Concrete block paving meets
today’s ‘Modern Methods of Construction’ requirements
for fully engineered, prefabricated products and
the increasing use of efficient, fully mechanised
site processes adds to this. A new Interpave document
highlights three recent examples of machine laid
concrete block paving projects.
Click here >
Download Interpave's new Environmental Impact of 
