Low Impact Development (LID) is commonly defined as: 'Development which, by virtue of its low or benign environmental impact, may be allowed in locations where conventional development is not permitted' (1).  More understandably, this means that LID housing is temporary in nature, made of natural / locally sourced materials, and is set within a greenbelt, farmland or a forest.  LID lifestyles are linked to the working of the land, and while this is a very romantic notion, being a carpenter or farmer probably isn't everyone's occupation of choice.  Given that the  62% of the US population is urban based (70% for europe), LID desperately needs to break away from its hippie and alternative lifestyle image. 

The Essentials of Low Impact Urban Living…

Sustainable living is at the very heart of LID, and some initiatives have already begun to make their way into our suburbs.  Community allotments, city farms, on-site power generation, green roofs, and brownfield development are all aspects of LID that are increasingly being demanded by designers and authorities.  However LID aims for higher standards and a more comprehensive approach that considers all aspects of sustainability.  The basics framework of Low Impact Development includes: 

1. Housing Affordability: LID housing must cater to a variety of budgets and ownership models that promote social equality.  Dr. Larch Maxey has written much on this subject and states that affordability is central to LID.  Authorities should consider establishing Community Land Trusts and designating areas of urban land specific for LID projects (2).
2. Transportation Links:  LID must be located near public transport and active travel (walking : cycling) routes.  It will always work towards a major reduction in private motor vehicle usage through vehicle sharing schemes.  This is becoming less of an issue in many european cities as electric car rental schemes appear, even in less dense urban areas;
3. Green Infrastructure: Integrate LID with open space networks and encourage good connections to recreation and nature.  Use LID as part of a land management strategy that works to restore or enhance wildlife habitats.  Promote SUDS to negate any flood contribution from development.  Promote food production at a scale that is appropriate.  This could be managed through on-site community management groups to ensure efficiency and share work loads;  
4. Energy Efficiency:  LID should promote off-grid self-sufficiency, for heating and electricity.  Initiatives that promote natural insulation, alternative energy sources and maximization of solar gain are critical, and tie into the wider issues of fuel poverty;    
5. Waste Reduction: LID housing must be low-carbon in both construction and use, with on-site materials re-used or recycled wherever possible.  Specialist housing items (ie: windows) should be locally sourced.  Initiatives such as rain water harvesting, grey water capture for landscape and food production, communal composting and on-site sewerage treatment should be considered where appropriate;
6. Economic Development: LID should promote a variety of local employment options, such as shared offices, ground floor retail, dedicated work-from-home spaces.  Every effort must be made to reduce commuting distances and create thriving local communities;
7. Management: Promote governance models that are participatory and empowering.  As noted by the Nobel prize winner Elinor Ostrom, such models take advantage of local knowledge / communication networks that usually already exist.  Tap into 'social capital' and give people a sense of control for housing developments that they are investing in.

Urban Examples of Low Impact Developments…

 

Fig 03 - Greenbridge, Chapel Hill (USA) is ranked amongst the top sustainable developments. Yet it fails as an example of LID, in terms of affordability & management. (Image: Greenbridge Dev.)

A Restrictive Planning Approach?

So why isn't Low Impact Development part of our daily urban experience?  There is a solid base of grass-roots activism within the community, yet LID lifestyles are far from the norm.  One reason for this is that planning policies are seen as a barrier and don't offer offer flexibility for LID housing types, lifestyles, land management processes or settings.  While policies need to be stringent to safeguard our natural resources and ensure a high quality of sustainability, there very little active promotion by local governments for such schemes.  Even if guidance exist, planners can over-interpret policies, causing undue grief to applicants and making the process excessively long and overly rigorous, something big developers will always shy away from. 

Policy Development - The First Step Forward

If cities and local authorities are to develop comprehensive LID policies, this will be a major step forward in urban living.  While land economics are different between the UK and the USA, there are similarities in approaches to policy development.  The requirements and supporting evidence for LID needs to be easy to understand and not overly burdensome, with clear assessment methods that empowers applicants to choose LID over conventional methods of living.  LID policy should emphasize the process as much as content, and consider the following:

1. Encourage a diversity of LID housing types, sizes, and locations (ie: Promote a variety of locations, including brownfield sites or dedicated LID zoning.  Also allow for self-build homes, industry build, and for the upgrading of existing / regular housing stock);
2. Offer variety and flexibility in LID lifestyle choices (ie: LID needs to accommodate a diversity of income sources, household sizes, management options, construction budgets and sustainability approaches, the responses which will be unique to each site); 
3. Balance high expectations and realistic approaches for sustainability (ie: Standards and targets need to be gradually phased in.  If too ambitious, LID housing will not occur at all.  If too lax, policies will have no meaningful impact); 
4. Provide a clear purpose, direction and commitment, with co-ordination at local /  national level (Approaches for sustainability and Co2 reduction need to link to other policies related to building codes, economic development, environmental protection and social equity); 
5. Policies, Targets and Assessment needs to be developed in an inclusive and relevant manner (Policies must be developed with LID practitioners, the construction industry, building suppliers, designers and planners). 

In conclusion, there is a major imbalance in LID expectations, planning policies and assessment methods.  This creates a culture where developers and commercial design practices stick to standard construction processes to maintain their profit margins.  Of the few schemes that have appeared, the most successful take into account environmental and social considerations, with an emphasis on affordability and long-term management.  This is critical to understand, as LID housing is not just regular developer housing with expensive technical solutions added in the name of sustainability.  Promoters of LID point out that Low Impact Development needs to be 'easy, attractive and affordable' (3).  Until we reach that point, our cities will never come close to meeting sustainability targets that national governments have committed us to.  

Sources

1. Fairlie  - Cited in Pickerill (2009), p.2
2. Larch Maxey, L. (2009) p. 71
3. Bioregional (2009) BedZED Toolkit, p. 3