GREEN TANK · RESEARCH ADDITIONS · 13 OCTOBER 2026

Housing choices, connected floating communities and environmental stewardship

A voluntary transition can build working communities with local infrastructure, housing choice and resident stewardship, then relieve pressure on existing settlements. This note identifies documented technologies and case studies for that programme.

AL’s settlement concept starts at approximately 5,000 residents, with the final development envelope reserved for a maximum of 50,000. Permanent green zones and transport or utility corridors are allocated from the start. Housing and business opportunities, local renewable energy, water management, sewage treatment, food production and environmental care are intended to develop together.

Evidence status: peer-reviewed research, completed projects, manufacturer documentation and proposed concepts are identified separately. A built example establishes that a system exists; it does not establish its affordability, universal suitability or environmental performance in a different location. The previous town maps were geographic scenarios, not ecological site assessments.

1. A phased transition with responsibility and opportunity

Establish a working pilotUse an allocated development plot selected through ecological, ground, flood and service assessments. Test local housing, power, water and sewage systems before expanding occupancy.

Enable voluntary movesOffer secure housing and livelihood opportunities. Assess whether each group of moves actually releases capacity in the older settlement’s housing and infrastructure, rather than relying on a population count alone.

Restore and improveWhere former urban land becomes available, assess reuse, removal of redundant hard surfaces, habitat restoration and public space. Track the construction impacts and transport effects of the transition.

Proposed stewardship condition: each household belongs to a resident-led environmental cooperative with a funded habitat management plan. Contributions can include planting, monitoring, maintenance, administration or a cooperative contribution, according to ability. Qualified staff handle specialist work. Existing wildlife, native species, habitat corridors, water quality and soil condition are surveyed before occupation and monitored afterwards.

Resident ownership should be accompanied by training, tools, transparent costs and accessible participation. It should not depend on every resident being able to undertake physical labour. This is a proposed governance approach, not a claim that a particular legal tenure already delivers it.

2. Concrete foundations are a choice within an engineered support design

Wall material, building form and foundation are separate decisions. A timber or straw building may use concrete; a lightweight modular building may use removable screw piles or pads. A floating home uses a buoyant hull plus moorings. Foundation selection must account for ground conditions, loads, wind uplift, drainage, durability and accessibility. Concrete remains an option where suitable and chosen.

WikiHouse’s technical guides explicitly describe ground screws and several other support systems. Wikkelhouse’s maintenance manual identifies removable concrete beams or screw piles, correcting the impression that a light building has no supporting foundation at all. [1] [2]

3. Housing alternatives to add to the study

“Tree ships” and “land boats” are treated here as working names for design families, not established regulatory categories. Tree ships mean elevated living among trees, including independently supported woodland cabins. Land boats mean relocatable dwellings on a chassis, skids or removable supports. Earthships are included as a distinct, established building concept.

OPTION	DOCUMENTED EXAMPLE / EVIDENCE	WHAT TO LEARN OR TEST FOR GREEN TANK
Open timber building systems	Technical system WikiHouse: CNC-manufactured timber components; guides cover screw piles, pads and other foundations. [1]	Study local fabrication, resident assembly, repairs and reuse. Specify the structure and support system for the site; open files are not a substitute for engineering checks.
Straw-and-timber homes	Built homes + experiments LILAC, Leeds: 20 households in a resident-managed development. University of Bath research tested prefabricated straw panel insulation. [3] [4]	A strong UK case for combining local material supply, shared facilities and resident management. Design drying, rain protection, ventilation and fire performance as part of the complete wall system.
Hemp-lime with timber framing	Experimental research Bath’s HemPod research assessed whole-building thermal and moisture behaviour. Hemp-lime is commonly used as insulating infill around a load-bearing frame. [5]	Investigate local manufacture of panels or infill. Keep structure and insulation functions explicit; do not assume hemp-lime replaces every structural element.
Improved earth/cob construction	Research demonstrator CobBauge, Plymouth/France: dual-layer earth construction. A 2026 study monitored drying and shrinkage in the first UK building. [6]	Explore locally available soil and fibre. Programme drying time, protection from rain and movement around openings; the published monitoring demonstrates why these details matter.
Earthships	Built demonstration Earthship Brighton is a community centre demonstrating solar energy, rainwater capture and onsite wastewater treatment. [7]	Study integrated household systems and local maintenance. The Brighton example is not proof that every Earthship design provides year-round comfort or sufficient water in every UK setting.
Removable modular houses	Commercial built system Wikkelhouse, Netherlands: assembled segments, documented relocation and removable supports. [2]	Useful for phased settlements and later relocation. Compare completed dwelling costs and lifespan, including services, maintenance and the site works.
“Land boats” / mobile homes	Commercial mobile dwellings Land Ark produces designed RV/trailer dwellings in the US. It is an example of the form, not evidence of UK residential approval. [8]	Define a locally manufactured, insulated, repairable dwelling with its own service module. Assess usable space, year-round moisture control, towing or relocation requirements and secure anchorage.
“Tree ships” / elevated homes	Built visitor accommodation Treehotel’s 7th Room, Sweden: a built elevated cabin with bedrooms and sanitary facilities. [9]	Provides a form to study, not proof of affordable permanent housing at settlement scale. Protect roots and tree health; assess access, emergency evacuation and services. Independent supports can be considered as a separate design choice.
Amphibious homes	Built flood-adaptation examples BACA’s Thames house rests on land and rises in floodwater. Maasbommel is another documented case. [10] [11]	A site-specific response to flooding. Some examples use concrete buoyancy hulls; amphibious does not automatically mean concrete-free. Flood access and flexible services are essential design questions.
Connected floating neighbourhoods	Occupied community Schoonschip, Amsterdam: 46 households on 30 floating units with solar generation, batteries and shared electricity exchange, occupied from 2020. [12]	The closest existing reference for shared floating housing and energy systems. It occupies sheltered canal water and remains connected to wider systems; it does not establish open-ocean autonomy.
Networks of ships / floating platforms	Research + proposals Peer-reviewed wave-tank and numerical studies investigate connected floating modules. OCEANIX is a design reference, rather than a verified operational city used as evidence here. [13] [14] [15]	Use the carbon-bond analogy as inspiration for a modular network. Determine connector forces, mooring loads, waves, motion comfort, damage isolation, utilities and access through marine engineering. Begin by studying sheltered sites.

4. What the scientific studies actually establish

Straw panels: Shea, Wall and Walker’s laboratory testing and modelling gave an approximate panel U-value of 0.178 W/m²K for the investigated system. That result applies to the tested construction, not every straw house. DOI 10.1177/0143624412450023. [4]
Hemp-lime: Shea, Lawrence and Walker compared experimental building co-heating tests with laboratory measurements and transient modelling. DOI 10.1016/j.conbuildmat.2012.04.123. [5]
Earthen construction: Fox and colleagues’ 2026 CobBauge monitoring recorded average vertical shrinkage of 43 mm over five months in the studied walls. This is evidence for designing drying and movement allowances, not a defect rate for all earthen housing. DOI 10.1016/j.cscm.2026.e06380. [6]
Connected floating modules: Choi and colleagues used a 1:63 wave-tank model with two modules and different connectors. Park and Nam’s 2025 research examined modular island motions and connector loads numerically. Together these support engineering investigation; they do not certify a residential fleet. DOIs 10.12989/ose.2024.14.3.277 and 10.1007/s13296-025-00934-y. [13] [14]

5. Giving back to the ocean: nutrient recovery rather than uncontrolled disposal

Food waste does not have to be buried in landfill. Composting returns nutrients and organic matter to soil; authorised anaerobic digestion can recover energy and nutrients. The food-waste hierarchy prioritises prevention and human redistribution before lower-value routes. [16]

Directly discharging food or other nutrient-rich waste into coastal water can increase nutrient pollution. Excess algae and decomposing organic matter consume oxygen, potentially harming or killing aquatic life. A local concentration of waste can therefore undermine the wildlife it was intended to help. [17]

A suitable marine research direction is integrated multi-trophic aquaculture (IMTA): fed species are combined with organisms such as shellfish and seaweed that use some of the particles or dissolved nutrients in the surrounding water. Species, stocking, flows, sanitation, nutrients and oxygen need to be monitored. This is controlled cultivation, not a disposal licence for domestic scraps or sewage. [18]

Well-sited shellfish and seaweed cultivation can also supply habitat and remove excess nutrients. NOAA’s research summary stresses that benefits depend on the local context and responsible site selection; installing farms over existing sensitive habitats could diminish the benefits. [19]

UK feed constraint: official guidance prohibits feeding catering waste and kitchen scraps to farmed animals. Some eligible former foodstuffs can enter a registered, compliant feed supply chain. The waste stream and intended species must be checked; an unapproved household-waste-to-fish loop should not be assumed. [16]

Ships also operate under rules restricting garbage discharges, including food-waste provisions. MARPOL is not a general permission to dispose of a settlement’s waste at sea. [20]

A practical Green Tank resource pathway to assess

Prevent waste and redistribute safe surplus food for people.
Route eligible food-processing by-products into a validated feed or material supply chain.
Use authorised digestion or composting for suitable remaining organic material.
Assess marine food production separately: native or appropriate species, suitable sites, monitored water quality and nutrient uptake.
Fund habitat restoration, litter removal and water-quality monitoring alongside floating habitation. Measure changes against a baseline; do not infer ecological benefit from the presence of the development alone.

6. Comparison criteria before choosing a pilot

Compare total delivered cost, resident comfort, accessibility, moisture control, fire performance, service independence during defined outages, maintenance skills, repairability, useful lifespan, embodied impacts, transport needs and biodiversity effects. Keep actual measurements distinct from proposed targets. An unusual form or natural material does not automatically make a home cheaper, greener or independent.

Sources and further reading

Open Systems Lab, WikiHouse: foundation guide and site preparation. Technical guidance for a building system.
Wikkelhouse: maintenance and relocation manual. Manufacturer evidence for removable supports and upkeep requirements.
LILAC cooperative: community overview and construction and energy description. First-party evidence of an existing community.
Shea, A.D., Wall, K. and Walker, P. (2013), prefabricated natural plant-fibre panel thermal testing, Building Services Engineering Research and Technology 34(4), 369–380. Peer-reviewed study.
Shea, A., Lawrence, M. and Walker, P. (2012), experimental hemp-lime building performance, Construction and Building Materials 36, 270–275. Also Bath structural research on timber framing and hemp-lime.
Fox, M., Carfrae, J., Morewood, J., Boutouil, M., Streiff, F. and Goodhew, S. (2026), CobBauge drying and shrinkage monitoring, Case Studies in Construction Materials 25. Project background.
Low Carbon Trust: Earthship Brighton. Community-centre demonstration.
Land Ark: mobile dwelling portfolio. Manufacturer information, not an independent performance assessment.
Treehotel: 7th Room. Existing visitor accommodation, not evidence of a permanent mass-housing scheme.
BACA architects: Thames amphibious house. First-party project account.
European Climate-ADAPT: Maasbommel case study. Adaptation example; its legal and cost history is location- and date-specific.
Schoonschip: community site; EPRI: completed project account. Evidence for sheltered floating housing and shared energy.
Choi, D.H., Jeon, J.M., Maeng, M.J., Kim, J.H. and Nam, B.W. (2024), wave-tank study of connected floating structures, Ocean Systems Engineering 14(3), 277–299.
Park, H.J. and Nam, B.W. (2025), wave-motion and connector-load computations for a modular floating island, International Journal of Steel Structures 25, 306–314. Open access.
UN-Habitat (2022): OCEANIX Busan design announcement. A proposal is not treated here as verified completion or occupied open-ocean housing.
UK government: food and drink waste hierarchy and animal-feed requirements. Current guidance checked for this note.
NOAA National Ocean Service: nutrient pollution and oxygen depletion.
NOAA Fisheries: integrated multi-trophic aquaculture. Includes links to a scientific workshop white paper.
NOAA Fisheries: global study of shellfish and seaweed ecosystem services. Research-team account addressing benefits and site selection.
International Maritime Organization: MARPOL Annex V and garbage from ships.