Welcome to our Frequently Asked Questions area
We hope to help you discover our approach to sustainability with a series of questions and answers. We offer more detailed information and guidance in our factsheets. These include data, pictures and drawings and can be purchased from our online shop or from us directly.
We do not charge for the information given below but do ask in return that you sign up to our newsletter which comes out about once a month so we can keep in touch. We hope you will enjoy its content and find the information useful and stimulating. Sign up here.
Basic principles of a sustainable housing development
What is sustainable development?
Sustainability is the creation and maintenance of systems that meets the needs of the present without compromising the ability of future generations to meet their own needs.
There are three key interacting aspects to sustainability: economic, environmental and social. If one of these is lacking, people will find it difficult to meet their needs.
What is the energy hierarchy?
The energy hierarchy places different energy services in order of their cost-effectiveness at curbing carbon emissions, and is key to our decision-making at Hockerton Housing Project.
- Conservation, or behaviour change, is the cheapest way to reduce energy use
- Energy efficiency, or ‘fabric first’ builds energy saving in, so energy savings are sustained over the life of a building or product for a relatively small upfront cost, More information available when we talk about choice of materials.
- Domestic or community-owned renewable energy can then be used to meet remaining energy demand; the less demand there is, the less you have to spend on renewable energy and heat systems
- The grid: the Government intends to decarbonise the national grid, but at present it is highly reliant on polluting fossil fuels.
Design and build
How did it all begin?
Members of the Hockerton Housing Project came together in 1993 to draft a proposal for five earth-sheltered houses to be built on a 25-acre site outside the village of Hockerton. The houses were to be the centre of a sustainable development using minimal energy and with little environmental impact.
How was planning permission achieved?
In August 1996 the Project made UK post-war planning history by obtaining special permission to build a sustainable housing development on agricultural land.
Planning permission was achieved despite a number of hurdles, including a comprehensive legal document, a section 106 agreement (see next question), attached to planning consent.
The wind turbine had to be applied for separately as there was not a specific model available at the time.
The fact that the houses would be energy efficient was not sufficient on its own. The project had to be viewed in its entirety, as “a move towards Sustainable Development”, which “could be seen as complimenting the council’s (Newark & Sherwood District Council) own energy / environmental activities”. Account was taken of the social provisions of the scheme – “(it) is not just for the houses in an isolated situation but as a whole living project…the occupants of the dwellings will work on the site towards a system of self-sufficiency through sustainable employment with low impact on the environment”.
A section 106 is a tool used by Development Control as a way of binding the applicants to carry out the development in the way specified in the agreement.
Associated with the agreement are two key documents which include most of the detail:
• Background Document
• Land Management Plan
Copies of the Section 106, Background Document & Land Management Plan can be purchased via the Shop.
Who were the designers/ architects?
Prof. Brenda and Dr. Robert Vale were the architects for the houses. They are internationally renowned for their work, including the New Autonomous House. They worked closely with Nick Martin, project member, who led the build of the autonomous house. David Leigh designed the water systems. Project members in conjunction with Newark & Sherwood District Council developed landscaping of the site.
How was the design chosen?
The intention was to achieve low construction costs by using a repetitive modular structure to simplify the construction and to make use of off-the-shelf components. This combined with minimal or even zero running costs could then reduce immediate and future potential financial burdens.
Nick Martin (one of the project members), combined his interests in renewable energy and low impact developments to consider various concepts that lead him to the earth-sheltered option. In the meantime he won the tender in 1993 to build the home of Prof. Brenda and Dr. Robert Vale, the UK’s first sustainable town house. It is an autonomous house with ‘net zero CO2’ emissions, of low embodied energy, deriving power from photovoltaic arrays and passive solar heating.
Nick Martin was so convinced by many of the construction principles that he commissioned Dr. Robert Vale to design a rural hamlet of 5 earth sheltered sustainable dwellings at the Hockerton site, to similar energy and environmental performance standards – autonomous and with ‘net zero CO2’ emission.
How were materials chosen?
Every effort has been made to use natural, traditional materials to their full potential. The use of standard off-the-shelf materials and products has been balanced with the benefits of ease of construction, cost effectiveness and reliable performance. The single storey, modular layout of the houses with repeating units allows for constant spans and economies of scale for fitments such as doors and windows.
Key factors:
• Physical properties including high thermal performance.
• Minimal embodied energy balanced by long-term energy savings.
• Minimization of environmental and health hazards by use of non-toxic products and materials.
• Minimal impact on land and resources.
• Environmental policies of manufacturers.
• Readily available, low to medium technology materials.
• Local supplies where possible to minimize transport energy.
More information is available in our factsheet on our choice of materials
Why earth-sheltering?
Five hundred tons of earth has been spread on the main part of the houses. There are a number of reasons for the earth sheltering:
• It reduces the visual impact of a development making the homes almost invisible from roads or points of public access
• It allows for the return of most of the ‘green footprint’ of the area taken up by the homes – much of the roof has been re-colonised by grass and local wild plants, as well as frogs, small mammals & their predator the kestrel! The stinging nettles are also an important plant for a number of British butterflies including tortoiseshell, that are particular abundant on site.
• Provide a temperature buffer for the homes due to its insulation properties and the fact that soil temperature lags air temperature by several months.
How is the energy used in the homes reduced so significantly?
The houses use about one tenth of the energy of a comparable conventional house i.e. approx. 8-10kWh/day.
This is achieved primarily by removing the need for space heating, saving over 50% of a conventional house’s energy requirements. More information is available in our factsheet on thermal design and energy conservation.
Hot water was initially produced via a heat pump and or super-insulated thermal stores saving over 50% of energy used by normal conventional hot water systems. Low energy appliances and light bulbs reduce the demand further.
How are the homes designed to keep warm?
The development has, as one of its main criteria, a requirement for extremely low energy consumption. This has led to a design in which there is an absolutely minimal need for space heating, thus eliminating altogether the need for capital expenditure and ongoing maintenance for a heating system. The houses therefore have no central heating system or any other form of secondary heating.
The houses are of a high thermal mass construction, which is able to store and release heat energy over a long period of time, thus maintaining a stable internal temperature somewhat akin to a storage heater. As air temperature drops heat is released. The materials that provide the bulk of the thermal mass are concrete blockwork, concrete beams and clay tiles.
The energy to heat the houses comes from the sun, human body heat and electrical appliances and the homes are designed to operate with an internal temperature remaining in the comfort zone of 19-21 degrees C all year round.
How was the self-build managed?
The project was managed by HHP as a self-build. Hockerton Housing Partnership was set up as a temporary legal entity to manage the construction of the development. All families involved had one adult represented as a partner.
Project members were responsible for about 50% of build, the remaining work being contracted to local labour and specialists. One of the project members, Nick Martin, an experienced builder of low-energy buildings, acted as a project manager.
How much did the build cost?
The estimated construction costs were approx. £450/m2, which is very favourable compared to conventional build)
Legal issues & Finance
What is the legal set up for house occupancy?
Due to the unusual nature of the project, the legal status of occupation needed to incorporate elements of the innovative set up of the project.
Each dwelling has an associated 999-year lease. These have a lot in common with standard leases, but with provision for the nature of the project. These include specific conditions, such as restriction on fossil-fuelled cars and an obligation to contribute a minimum number of hours to the cooperative.
How was the project financed?
Primarily, the foresight, willingness and flexibility of Co-operative Bank & Ecology Building Society to work together overcame the challenge of financing the project. The Co-operative Bank initially provided loans, which were later converted to mortgages with Ecology Building Society. These two organisations specifically support projects with environmental aspects.
Due to the unusual nature of the development and the fact that it was a self-build, many conventional lenders were unwilling to consider financing the project. This is typical of many other self-financed ecological building schemes.
An internal contract was agreed within the group committing each family to provide finance up to a common stage of development. Each family had to separately fund their share of the work. A finance sub-group calculated relative payments and a position of equity were achieved on a monthly basis
Performance
Are the homes really warm enough in the winter?
There are temperature variations between the houses. These are dependent on occupancy rates and desired comfort levels. In one house the temperature has never gone below 18oC in seven winters. More typically the temperatures in most houses during winter are 18-20oC. In homes where occupancy levels drop below those used in the design calculations (e.g. holidays or kids leaving home), short periods of supplementary heating with mobile heaters are used. However because less energy is used in these homes for other purposes the overall energy use is not significantly different from other homes. On the other hand project members are frequently found complaining that stays in more conventional homes are too cold! More information is available in our factsheet on thermal design and energy conservation.
What stops heat escaping from the homes?
There are many ways in which heat can be lost from a home. At Hockerton, the massive insulation and earth covering are key features in this respect. This then leaves glazing and ventilation as potential weak points in the design. The key means to preventing heat loss are:
• High levels of insulation to all external surfaces of the house
• Reduced temperature gradient between inside and outside of house by use of buffer zones, i.e., conservatory and porch
• The roof, rear wall and two end walls are earth covered
• Use of glazing configurations (triple and double glazed, with low E coat and argon fill) with very low heat loss specifications in the main part of the building.
• Careful management of the ventilation of the building through the use of mechanical ventilation with heat recovery.
Data, pictures and drawings on construction is available in the construction factsheet.
Is the choice of glazing important to energy efficiency?
Glazing is an important feature of the houses both in terms of energy performance and aesthetics. At Hockerton, the homes are SW facing, which gives a slight emphasis to afternoon light. The elevational design, enhanced by the roof angling upwards makes good use of low winter sun penetrating to the back of the dwellings. This design, therefore, both provides good internal daylight and maximizes passive solar gain through the conservatories.
Double-glazing has been used for the conservatories and triple glazing for the doors and windows to the main part of the houses. Importantly, they are all made using ‘low emmissivity glass’, or low E glass. This allows the sun’s heat and light to pass through the glass into the building but at the same time it is highly reflective of the energy emitted from within, such as from warm surfaces. This considerably reduces heat loss and adds the equivalent of one pane of glass in terms of thermal performance, so that double-glazing becomes as effective as triple.
Are the homes dark and dingy?
Absolutely not! A common vision conjured up by an earth-shelter is a dark & dingy one, where hobbits and troglodytes might be more at home.
The homes have been designed to maximise light input when occupants most need it in the depths of winter; the pitch of the ceiling matches that of the shallow sun at its winter equinox. This allows sunlight to penetrate fully to the back walls. Conversely at the summer equinox there is minimal light penetration through the building self shading itself from the high sun. This however helps prevent over-heating of the building.
The conservatories are obviously well lit, whilst the very large windows and doors that open onto them provide good lighting to those rooms where it is desired, such as lounge, kitchen and bedrooms. The back of the houses where natural daylight is reduced, have been reserved for areas that such lighting is not an issue – such as bathroom, shower, and utility room.
How is over-heating prevented?
Due to the very high levels of glazing and house orientation, typical of passive solar homes, some consideration has been required to ensure that at certain times of the year this does not lead to over-heating.
During the summer, self-shading is created within the homes due to the high angle of the sun. This reduces thermal gain and brightness inside. This shading is augmented by the use of blinds within the conservatory. The houses are also ventilated through a large opening light in each bay adjacent to a corresponding light in the conservatory roof.
On what basis were interior finishes chosen?
The interior finishes were selected in keeping with the principles used for choosing building materials. This included choosing products from sustainable sources, of minimal embodied energy, recycled materials where possible and of low potential toxicity.
Wood products were sourced from sustainable timber sources. Paints were chosen that were low in ‘Volatile Organic Solvents (VOC’S)’. PVC wiring and pipework were substituted with alternatives. Clay tiles were used rather than carpets (tiles are more natural, have a lower embodied energy and last longer). Where possible formaldehyde compressed boards were avoided. Many items, such as kitchen units were made from recycled materials.
Are the homes comfortable to live in?
The Hockerton homes have been lived in by five families for more than seven years. The houses were in many ways a new design concept, so there was some uncertainty about how comfortable they are to live in.
The independent monitoring of the homes concluded – “The houses at Hockerton are a successful experiment in low energy design. They are attractive and pleasant to live in.”
(New Practice Profile 119 – The Hockerton Housing Project – design lessons for developers and clients, BRESCU- Energy Efficiency Best Practice Programme.)
From the occupants perspective the homes have proved to be comfortable and attractive, as well as interesting. They have performed well, with occupants only using 10% the amount of energy used in their previous homes, whilst remaining comfortably warm in the winter.
Most visitors comment on how pleasant the homes are and how warm in the winter – indeed often warmer and more comfortable than their own. Anyway why not come and visit us and judge it for yourself! See HHP Events & Tours
Services
How is water heated?
The second biggest consumer of energy in a home after space heating, is generating hot water. Because at Hockerton there is no need for space heating, our hot water has become our biggest user of energy. It was therefore important to find ways of minimising this.
Initially all homes were fitted with ‘Air to Water’ heat pumps to provide hot water. This system utilizes excess heat created in the south facing conservatories. The hotter the air, the more efficient the system becomes – however they are capable of providing hot water energy efficiently at relatively low temperatures. There is a high capacity for storing such gains during hot periods or via excess wind energy, due to the very large hot water tanks, which have a capacity of 1,500 litres. Overall the combined system of heat pumps and super-insulated thermal water stores reduced the energy requirements for hot water by about 75%.
However more recently, with the failure of some of the heat pumps (and no replacement/repair available) HHP members have been researching how effective smaller scale super-insulated stores can be developed as more energy-efficient systems compared to conventional hot water tanks. The ‘Hotsi’ tank has been installed in a number of homes. They have been integrated with conventional immersion units and have proved to be very energy efficient.
Data, pictures and drawings on our hot water system are available in the Hot Water Systems factsheet.
How important is ventilation?
For the full picture see our factsheet on ventilation and house construction. At Hockerton the houses are remarkably well sealed. There is therefore the potential for humidity and pollutants to reach much higher levels without adequate ventilation. What is required is a balance between energy conservation and adequate ventilation.
Mechanical ventilation and heat recovery in each house at Hockerton is by means of an air management system. This extracts stale air from wet areas (toilets, bathrooms and kitchens) while at the same time introducing an equivalent volume of pre-heated, clean filtered fresh air to the main area of the house where heat gain is the highest. Up to 80% of heat is recovered in this way.
In keeping with Hockerton’s ecological principles, clay has been used for the supply and return air pipework to the ventilation units. Suspended from the ceiling they make an interesting design feature.
How is water conserved?
The houses use about 25% volume water compared to a conventional home. This has not been achieved however through any discernible loss of convenience or comfort, but by simple conservation measures. ‘Building Services Research Association’ (BSRIA) monitored the water use in the homes for almost a year.
Water conservation measures include; low flush toilets, flow restrictors in showerheads and showers are used in preference to baths.
Is the project self-sufficient in water?
Drinking water is collected from the five conservatories with an estimated annual catch of at least 90’000 litres, i.e. 90m3 (based on approx. 50% average rainfall).
If each person uses 5 litres of drinking water per day and there are 20 people, then our annual consumption will be 36’500 litres. Therefore, potentially we could collect three times as much as we need in a poor year! However at any one time we can store up to 25’000 litres, which when full would last approx. 250 days. In practice we rarely fall very far below full. A comprehensive description of our water systems is available in our water supply fact sheet.
Non-drinking water is collected from the back of the houses, the road and surrounding fields. It is then channeled into a sump from which it is pumped to a reservoir for storage. The reservoir stores 150m3 of water, which is equivalent to approx. 100 days use by the project members. Again in practice this store has proved to be more than sufficient rarely going below half-full.
There is also a separate collection and storage system for water supply to the food growing area.
How is collected rainwater made safe to drink?
Although it is common throughout the world to drink water untreated, we are filtering and treating the drinking water to a very high standard. The water systems have been monitored independently by Building Services Research Association & more recently by Loughborough University proving their quality.
Collected water is stored in underground cool, dark tanks that provide a clean environment. The water is then passed through a 5 mm string filter to remove any remaining small matter, and then through a combined carbon/heavy metal filter to remove any dissolved chemicals & heavy metals. Finally it is subjected to ultra violet light to kill bacteria or viruses.
Non-drinking water goes via a sand filter before reaching the houses. This removes particles and has some bacteriological action. However this is not designed for drinking purposes. Filtration and data on microbiology is available in our water supply factsheet.
How is wastewater treated on site?
A reed bed system cleans up the outflow from septic tanks by supporting a highly active eco-system. Their roots supply oxygen to bacteria in the water, which digest the pathogens in the sewage. The lake water into which the reed bed flows has been tested independently and shown to meet bathing water standards. It also looks good, supplies nutrient-rich water to the lake (and fish) and the waterfowl love it!
What forms of renewable energy are used on site?
HHP erected a 6kW Proven wind turbine in early 2002 and in August 2002 complemented this with the installation of a 7.65kWp array of photovoltaics (generation of electricity from solar power). The HHP wind turbine was one of the first examples in the UK of a community owned wind turbine, whereby the owners are supplied directly with the ‘clean’ renewable energy produced. The original photovoltaic system was funded through a DTI photovoltaic domestic field trial grant, with some match-funding from Powergen. we have a lot of further information on all our renewable energy systems in two of our factsheets, Energy Generation a and b.
The new offices and visitors centre was designed to meet the same high standards as the homes and is powered using energy generated from a second wind turbine on site. This turbine is from a local company Iskra, and is of a similar size to the Proven machine. Additional PV panels were added in 2012 as energy use is higher than predicted due to the level of work onsite, and to prepare for electric cars.
What is the most effective form of renewable energy?
Wind power is the most cost-effective way for HHP to produce renewable energy, generating power at about half the price/kWhr compared to the photovoltaics. It uses minimal land, has very low embodied energy and can be easily decommissioned at the end of its life. For other sites this may not be the case, but in general wind power is very cost-effective compared to other forms of renewable energy.
What happens if the renewable energy systems do not produce enough power?
All of the systems are grid linked, which allows for both import of energy during periods of supply shortfall, and export for periods of excess energy production. The excess exported offsets the imported energy from the grid. The process is therefore seamless, with occupants unaware of when the system moves from import to export or vice versa.
How much energy do the renewable energy systems produce?
The wind turbines were expected to produce around 12,000kWh each annually with the wind conditions on site, whilst the roof-mounted photovoltaics a further 6,000kWh and 5000kWh.
In practice the wind turbines have produced only 40-50% of their projected output. The photovoltaics have however generated very similar amounts of energy to those estimated. The energy generated by the wind turbines have cost only half the amount per kWh compared to the initial photovoltaic panels. The new PV system is more comparable in cost.
There are a number of possible reasons for the lower energy production from the wind turbines:
• More turbulence than expected from the line of trees to the south west affecting energy capture from that direction
• Lower wind speeds generally than expected
• Initially inverters not optimized for wind turbines as they were designed for photovoltaics. (New chips were installed in the Proven inverters in 2004 that more closely reflected wind turbine profiles, the Evance ISKRA now also has dedicated chips for turbines).
Is enough renewable energy produced to meet the site’s energy needs?
Due to the very low energy requirements of the homes at HHP (about 10% of an average UK home) relatively small renewable energy systems were expected to be able to produce enough energy to offset the occupant’s energy use. However the wind turbines have underperformed (see previous question) and the energy use on site is higher than originally envisaged (in particular the growth of the on site business and purchase of an electric car). However most of the increased use can be justified by offsetting less efficient (& non-renewable) use elsewhere, such as working off site & fossil-fuelled transport. This situation persisted for a while until we installed more renewables on site.
The approximate usage and production breakdown can be found in the factsheets. With the systems installed by 2013 all the house energy is produced over a year by the onsite renewables.
Why do the homes have a higher energy demand than planned?
• Those homes with teenagers have observed a significant increase in energy use, which disappears when the teenagers depart!
• Failure of ‘water to air’ heat pumps (no longer available) in 4 out of 5 homes to heat water. The replacement energy efficient systems use more energy than the heat pump systems.
• Food processing for cooking and storing site grown fruit and vegetables has increased over the years – however this offsets shop bought food which is much more energy intensive through manufacturing, packaging and transportation.
• More work from homes than initially expected.
• The water supply and treatment systems use energy via pumps (this offsets energy that is used to supply homes on mains systems, but is a hidden cost in water bills).
Community Set up
How did the members of the project come together?
Nick Martin, current landowner, builder, member and ex-resident of Hockerton Housing Project first became interested in a sustainable development in the early 1990’s. His family acquired the site and with other family and friends formed the nucleus of the group. Other project members joined the project through advertising for new families whilst some early members left for various reasons, including length of time to gain planning permission.
Were there any difficulties in the early stages?
It was difficult at times in the early stages to keep project members motivated. For many years the project was at a concept stage and went through a long period of deliberation over planning permission. This is typical of many similar projects. It can also be difficult to find potential members and gain commitment (mainly time, but also financial) for something that may not be successful. The main ways the group held together in the early years was through developing the organics area together and regular meetings (of course spiced with a little wine!).
How was the project constitution developed?
A constitution is a document that provides the framework for the way an organisation operates. It explains what the organisation is, what its purpose is and what the rights and responsibilities for members are. This is particularly important when money becomes involved. The constitution also states the basis of how decisions are to be made by members. However these often do not cover more practical aspects of living and working together as a community.
Hockerton Housing Project Ltd was set up as a company responsible for the overall running and maintenance of the project. The management team is made up of all the adult occupants who are its directors. It is a co-operative company and so has a set of ‘Memorandum and articles of association’ in line with other co-operatives.
Over the last few years the group has developed a more detailed set of ‘secondary rules’ used to cover other aspects of living as a community, such as leaving & joining procedures. This is an evolving process as we add new elements and fine-tune others.
What are the community aspects of the project?
Project members have as a condition of their lease to contribute towards communal project activities. Each adult is required to spend a minimum of 300 hours per year on such work. Where payment is involved there is equal pay.
The main issues are distributing work and finding sufficient time to do all these activities. It is also important that everyone remains committed to the aims and success of the project.
There is a communal responsibility to maintain utility services, such as water and energy systems. The group has a communal organics area for vegetables, fruit and beehives and an aquaculture lake stocked with fish for consumption. A small range of animals are kept for eggs and meat.
The group also has a separate ‘Trading’ company to manage all income generating activities.
There are also numerous social aspects, such as regular meetings, parties, shared car and child-care arrangements.
Is the project self-sufficient in food?
The project has as one of its key aims to grow organic foods, including vegetables, fruit, honey, eggs, fish and some meat. There is a limit to how economically sustainable it is to grow our own food or grow excess for sale.
The group is about two-thirds self-sufficient in vegetables and less for fruit and meat. The hives meet our honey requirements most years. Wine and cider making makes use of some fruit/vegetable excesses.
We aim to supplement what we produce ourselves with mainly locally grown, in-season food to minimise on ‘food-miles’ and support local economy. This is not always easy (particularly bananas)!
A large proportion of other general foods and household products are bought as bulk purchases from ‘SUMA wholefoods’.
Business aspects
Why is there a trading part to the project?
When considering the application for the Project, the planning authority expressed concerns about its sustainability claims; In particular that the project would not create employment on site, but that the occupants would be most likely to commute to centres of employment and require significant transport journeys for shopping etc. They wanted the application to define clearer ways of ensuring that occupants would have employment opportunities on site or nearby, thereby reducing the need to travel.
Creating employment is therefore a key project principle. Finding sufficient paid work to make it viable is the challenge, but with increasing success as environmental issues grow, HHP has become more established and credible.
What is the business?
Hockerton Housing Project Trading Ltd is a separate company set up with responsibility for all the commercial ventures associated with the project. All members of the management team of Hockerton Housing Project Ltd. are directors of this company. It is a not-for-profit co-operative company, with clear environmental objectives. Its mission statement is:-
“By practical example, act as a catalyst for change towards ecologically sound and sustainable ways of living”, now summarised as “bringing sustainability to life”.
Tours are offered to members of the public and well as bespoke visits for larger groups, more information here.
We also offer design advice to help people create low energy houses and commercial buildings and we help them to save money when they come to build their own designs by reducing costs of construction at the design stage.
We also support communities to install and run renewable energy generators.
Other
What is the transport policy?
As a condition of the lease each household is only permitted one fossil-fuelled vehicle.
This is supported by having a wide range of bikes for different uses, and two families share a car. The Project had an early electric car but unfortunately the manufacturer (Peugeot) stopped supporting its maintenance in 2008. We are now waiting for EVs to drop in price, but have invested in additional solar panels in part to fuel future electric cars.
Whenever possible bikes are used for short journeys, despite poor provision for cyclists on local roads. The Project members are campaigning for a cycle and foot path to link Hockerton to the local schools and shops in Southwell and to the Sustrans network.
Is there a policy on recycling materials?
Materials are recycled wherever possible. However this is supplemented by re-using as many waste materials again on site, or avoiding unnecessary materials in the first place. Growing our own food reduces a lot of food packaging. As a result our bins are emptied only about once a month. All organic waste is composted on site.
Tin, plastic, cardboard and paper that cannot be reused is placed in council ‘silver’ bins and collected fortnightly for recycling.
Many of excess building materials were saved and have gradually been used by project members for homes and gardens.
Have the changes to the land improved its biodiversity?
There was concern that the Project would have an adverse affect on wildlife, through the disruption of building work and occupation. Prior to the construction the land was basically low grade agricultural with a typical mix of farmland birds. However the land did have a good range of wildflowers and grasses due to minimal use of chemical sprays.
The construction of the homes was associated with the development of a lake and several ponds. Over 4,000 trees have been planted around the site, including willow for coppicing, wild cherries for birds, and oak and hazel.
Rather than having a negative impact on wildlife, the site has experienced a flourishing of wildlife, with an increase in biodiversity, primarily via the lake, ponds and maturing trees planted. There are now 5-6 regular breeding waterfowl on the lake, including little grebe. A number of passing bird migrants have been seen including green sandpiper, hobby and water rail. The ponds are monitored by the local agricultural college (Brackenhurst) with particular interest in a flourishing population of the endangered water vole. Many species of dragonfly are now regulars and new species of water plants colonise the new water habitats.
Is it ok to have a TV and dishwasher?
HHP is not necessarily about avoiding modern technology for labour intensive methods or sacrificing comfort and convenience. It maybe that sometimes this is the case if a new technology is particularly poor from an environmental perspective. The project is more interested in harnessing appropriate technology.
Most families have TV’s, computers, microwaves, etc, although leaving them or any other appliance on standby is frowned upon!
Dishwashers are used by some families as their water and energy efficiency has improved in recent years, but there are no tumble-dryers – these are not needed since clothes dry very effectively on racks suspended in conservatories.
How much money is saved by living in these homes?
Energy and water reductions have resulted in savings of over £1’000 per year per household. This is likely to grow significantly in real terms as energy prices increase.
It is harder to assess other savings, but there is no doubt that there are economic benefits from the food self-sufficiency activities, recreational facilities and sharing of equipment and other resources.
Can the principles at Hockerton Housing Project be replicated?
From the very outset the Project has been recognized as a possible model for sustainable living. The massive interest that it has attracted indicates that there is a desire to seek new ways of living that reduce their impact on the environment.
HHP has been very encouraged with the interest from developers, housing associations, and district councils, architects and planners, who are eager to learn more.
“The project could be easily replicated with its communal philosophy although the house design could be quite different and still have the ultra low energy features. Such a communal enterprise could be extensively repeated as there have been, and exist, many successful small communities. The biggest factor for its continuance will always be the will of its participants. Overall the Hockerton housing scheme shows a refreshing combination of boldness and realism in taking on the seemingly insurmountable Agenda 21 challenge of the next century.”
BRE interim report as part of a monitoring programme on behalf of the ‘Energy Efficiency Best Practice Programme’ – now managed by Energy Savings Trust