Monday 19 April 2010

Towards a New Garden City


Argument
The opposite pulls of living in either the city or country have changed since the proposition of the Garden City Movement in the 1890s.

The countryside is no longer available to accommodate significant populations on an agrarian model, and is now more a recreational resource as well as supporting intensive farming.

Cities are regenerating and expanding to become conurbations of regional proportion, generating stress, pollution and alienation, as well as providing a place of work, excitement and opportunity.

However, the values of the Garden City at their lowest level have produced an endless suburbia, quite different to the vision of Ebenezer Howard. Suburban development now accounts for approximately 70% of the population in the UK but suffers from being monotonous, restrictive and conformist.

The three magnets famously illustrating the concept of the Garden City have been reduced to two: The City versus Suburbia.


City Versus Suburbia
However, both paradigms require radical overhaul as desirable models for living. In this proposal the focus is on low to medium density development, now typified by suburbia and hence the need for a vision of Tomorrow’s Garden City.

In this transformation of suburbia, a sense of community and variety of opportunity must be proposed in the organisation of the physical environment. Similarly, the erosion of available land must be arrested as currently typified by the wasteful sprawl of repeated on plot detached or semi-detached houses or the rise of mini gated estates and increasing car densities.
Our proposal aims are therefore to:

- Create a better distribution of land
- Create a balance between private and communal space
- Engender a sense of community and active participation
- Create a framework for a variety of life styles and live/work
   opportunities
- Provide a fully sustainable and energy efficient environment

Demography and Housing Demand
Within the overall demand for housing there is a trend for smaller scale dwellings, of one and two bedroom accommodation. This is partly due to the decreasing size of the nuclear family, the needs of single parent families, the rise of young working couples or partners and an ageing population of active couples downsizing.

The categories of lifestyles requiring one/two bedroom apartments, include therefore a mixture of cash-rich, time-poor young professional single people or couples; cash-poor, time-poor single parents; and cash-neutral, time-neutral retired couples. Common to all these lifestyles is a limit of either time or energy to support the maintenance and upkeep of excessive private outdoor space, that can be generated in the front and rear garden. However, the individual’s ability to input to and benefit from outdoor space is vital, whether in gardening, recreation or the enjoyment of greenery and open space.
In our proposal we explore the possibility of a rich and inclusive community drawn from these categories of families, hence the concentration on a mixture of one and two bedroom units. However, our concept is not exclusive to small scale accommodation, and we indicate how the model can also accommodate a percentage of larger family units without prejudice to the concept.
  
Town Planning Issues
The need for buildings in scale with the community they serve is essential for a sense of community, rather than the repetitive expression of the smallest unit of living as the sole means of space making. The scale of a large detached or semi-detached house is a well loved and familiar element in a setting akin to the Garden City. This scale of development is something that our proposal wishes to emulate, i.e. the Villa or group of cottages.

Secondly, the rise of private transport and the need to accommodate the motor car associated with housing has further lead to the erosion of space and scale of building. We therefore propose to create more flexible accommodation for the car, anticipating a change of attitude toward private transportation and the growth of live/work activities.

The Concept

Basic unit
The basic living unit in our proposal (as stated above) is a one/two bedroom L-shaped apartment. These units are interlocked to form a central space from which each apartment is entered. The apartments are arranged over three storeys making a generic block of six units.

Atrium space
The central space created becomes a dynamic top lit enclosed communal threshold space, mediating between the outside public realm and internal private space. By combining opening lights at ground and first floor levels with opening roof lights this space becomes a cool ventilated interior space in summer, and with windows and roof lights closed in winter becomes a passive preheated area. Furthermore, the enclosing walls that form this space are proposed as unfired brick, providing a large area of exposed mass, to control the fluctuations in temperature.


Within this space, rainwater from inward sloping roofs is collected in high-level sumps to irrigate vertical planting on two internal walls, creating attractive green walls of complimentary planting, dependent on orientation. The choice of plants can range from scented and flowing shrubs, edible fruits and herbs, to mosses - all supported on frames of compost-less mats requiring minimum upkeep and maintenance. At ground level in this space a shallow pond is created to additionally provide a thermal store and to generate atmospheric moisture to promote the growth of the green walls, creating a micro garden for the benefit of the occupants. This pond also symbolises the fact of underground rainwater storage tanks used to supply private apartments with WC flushing water and to irrigate outside communal
garden areas.

The Villa
The six-apartment atrium is mirrored on plan to become the Villa, containing twelve apartments with two atria. This is the principal architectural housing component, which can be grouped to form communities of up to five or six villas in size, yielding between sixty to seventy apartments. In this manner, exploiting the need for smaller units combined in compact groups reconciles the perceived view of garden cities comprising low-density housing and the current national planning policy for higher densities. 

Each Villa of twelve apartments is provided with a simple and efficient method of household waste and refuse disposal accessed from the apartment’s kitchen door. At each floor level a screened communal recycling drum is formed with six waste chutes (noise insulated) for segregated waste disposal (household, green/organic, glass, metals, plastics, paper) that are collected at ground floor into 360 litre capacity bins for collection. Green waste is intended for making compost used in communal allotments and gardens.

  

Internal Apartment Organisation
The dwelling is intended to be built ‘airtight’ to control unwanted air leakage, is to be well insulated thermally to reduce energy consumption together with sufficient exposed thermal mass, combined with night time ventilation to act as a thermal flywheel. Opening windows to all spaces are triple glazed (2+1) metal-faced timber assemblies to provide controlled natural ventilation, incorporating integral night-time trickle vents. Trickle vents to the atrium space work in conjunction with solar powered rooflight actuators utilising the atrium’s stack effect to further ventilate the apartments in hot conditions. All WCs are low flush and grey water flushing and low energy lighting is to be pre-installed within dwellings as well as for communal lighting. 

Heating
Given the levels of thermal insulation, heating demand is minimal, to be provided by radiators supplied from central solid biomass (wood chips or pellets) boilers. 

Hot Water
50% of domestic hot water is provided by south facing roof mounted evacuated glass tube solar thermal panels, supplemented with hot water from the biomass boilers.
Under the strategy of 100% of the space heating demand being provided by the biomass boilers and 50% of the hot water heating demand being undertaken by the solar thermal panels the scheme will save 72,242 kg of CO₂/yr. This represents a reduction in CO₂ emissions from a Building Regulations compliant scheme of 42.3%. The reduction in CO₂ emissions from Energy Efficient base case (i.e. % reduction from renewable) is 37.8%. The biomass boiler will cope with 178,400 kWh/yr of space heating demand, whilst the solar panels will cope with 80,200 kWh/yr of hot water demand. 

Cooking
As an option to natural gas, electric induction cookers are to be proposed, both from energy and safety points of view. Induction cookers consume half as much electricity as electric cookers and are more efficient in heat transfer, achieving an absolute efficiency of 84% (compared to a typical 40% for a gas cooker). Induction cooking power savings of 40-70% are realistically achievable in comparison to conventional cooktops. 

Site Planning Opportunities
Due to a definitive site not having been established, our proposal is necessarily diagrammatic at this stage. Given the imperative to make efficient use of land, we have tended toward higher density levels than existing densities in Letchworth Garden City.


Vehicular Provision and Live/Work Units
We intend that space allocated for car parking is a positive element, that can be adapted and changed by a series of add-on’s from a kit of parts, into an extension of many lifestyle activities. The basic provision is a covered space with side-walls of unfired brick. Roof-mounted photovoltaic panels provide electricity for the batteries of hybrid or electric powered cars. The enclosed volume, within each ‘car-port’ allows for a mezzanine to be added with steps up for additional space, which combined with enclosing the front and rear elevations, in either glazed or solid panels, with doors and screens as necessary allow the spaces to adapt organically into storage areas, workshops, or studio and office spaces.

Particular end units in the parking terraces are given over to communal enclosed space, to facilitate community centres associated with allotments, play groups, tenants meeting spaces, garden stores etc. Other uses for these end units are as the central biomass boiler plant and solid fuel storage. 

Pedestrian and Cycle Routes
Pedestrian and cycle routes are separate from the vehicular routes, and lead to all communal spaces. Cycle parking is associated with each Villa, provided in covered, secure shelter. The car-port/workshop units offer additional bicycle storage space. 

Private / Communal Open Space and Allotments
Private space is specific to each apartment, comprising south or southwest / southeast facing balconies. These balconies are covered to provide solar control in summer, but to allow low angle winter sunlight into the apartment. Movable planting boxes on the balconies provide the occupant with flexible, close-to-hand planting options.

The remaining released land is designated for communal use. The range of uses is open ended, but typically space for picnics, parties, sitting areas, toddlers play and landscaping are imagined. The management and upkeep of these spaces would be administered and funded by a tenants and house owners trust, who would contribute a small annual ground rent in the property deeds, combined with an equal stake in the control and management of their own local community, of say up to around 60 to 80 dwellings. Clearly, these small associations could combine if they wished to share costs of landscape maintenance or upkeep.

In addition to the shared landscaped communal space, allotments are initially provided in a ratio of approximately 1 for every 3 apartment, to provide space and stimulate active gardeners. These allotments would be leased by rotation if necessary to cater for wider demand. Recycled organic household refuse for compost is built into the system. Again, the proposal is open-ended, and can be tailored to each community’s changing needs, with the proportion of landscaped to ‘farmed’ space being evolved by the trust.

Pond, Reed Beds and Coppices
An exciting spin-off use of harvested rainwater, grey and black water recycling is the creation of a large central pond, which is designed to filter water through a maze of gabions with floating reed beds and microorganisms into a clear water pond. The pond would be fit to support wildlife and fish, and to provide a wetland habitat for locally endangered species referred to in the Hertfordshire Biodiversity Action Plan, such as the white-clawed crayfish. This pond can also support fish that can be harvested annually. In swathes of communal areas, coppice willow is proposed, as a contribution toward the fuel for the solid biomass boilers, providing additional filter beds for pond water, as well as providing habitat for biodiversity of wildlife. We believe that the coppicing can provide fuel on a three-year rotation cycle of growth, maturity, and cropping (providing between 10 to 15 % of the total demand).

Summary
Our strategy is to employ a holistic approach to sustainable development and the creation of an environment to promote a range of activities and lifestyle opportunities for the individual and the community. Our aim is to conserve energy, release time and promote the well-being of inhabitants in an environment akin to the original ethos of the Garden City Movement.


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