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Owned by residents.
Open to the world.

TRAPEZIUM Community Investment began as a handful of neighbours determined to own their homes together. Today it is a thriving cooperative and a forum where what we learn locally informs a global conversation on housing and health.

Our Mission

Two missions,
one platform.

We exist to give residents secure, affordable, healthy homes through cooperative ownership — and to share what we learn so others, anywhere, can do the same.

Our content is local: the gardens, the bylaws, the maintenance rotas, the retrofits. Our analysis is global: how those local solutions speak to climate resilience, housing rights and environmental health far beyond our street. We call it the glocal approach.

Since 2019From a neighbourhood idea to an international forum.
Who We Serve

One platform, three
audiences.

Trapezium is built to serve the people who live here and the people learning from us around the world.

01

Our Members

Residents who need voting rights, maintenance requests, document access and a genuine voice in how the cooperative is run.

02

International Peers

Other cooperatives, NGOs, academics and urban planners exchanging research and lived experience across borders.

03

Policy Makers

Officials and institutions seeking practical, evidenced case studies on social housing and environmental health.

Our Story

How a street became
a movement.

19

Founded

Neighbours pool resources and form a resident-owned cooperative built on one-member-one-vote.

21

Going Green

First retrofits and shared gardens turn environmental health into a founding principle.

23

The Forum

We open our case studies to the world, launching an international forum for shared learning.

Now

Scaling Up

The Collecting Project channels members and donors into funding the next generation of homes.

Governance

Run democratically.
Held accountable.

Every member has an equal say. Our governance is designed to be transparent, participatory and resilient — the same model we research and share with the forum.

General Assembly

All members vote on budgets, bylaws and major decisions — one member, one vote.

Elected Board

A volunteer board, elected from and by members, stewards day-to-day operations.

Open Accounts

Finances are published to members in full — the Collecting Project is auditable by all.

Shared Bylaws

Our rulebook is open-source — free for other cooperatives to adapt and improve.

Meet the people

Elected by members.
Accountable to members.

Our board is volunteer, term-limited and elected at the General Assembly. Every member can stand and every member can vote.

HO

Helen Okafor

Chair

Founding resident. Twenty years in tenant-led housing in South Yorkshire.

Term: 2025–2028
MO

Mark Olembo

Treasurer

FCA Mutuals specialist accountant; treasurer of two community-benefit societies before Trapezium.

Term: 2025–2027
RM

Dr. Rosa Mendoza

Secretary & Forum Lead

Lecturer in Housing Health, UCL. Author of the network's first damp-and-health protocol.

Term: 2024–2027
CM

Cllr Catherine Mason

Independent NED

Local councillor and former Director of Housing; chairs our complaints sub-committee.

Term: 2025–2026
PA

Priya Ahmed

Member Director

Open Member representative. Leads the inclusion working group and Saturday community kitchen.

Term: 2026–2028
TC

Tomás Cabral

International NED

Chair of Cooperativa Habitar (Lisbon). Brings cross-border governance practice to the board.

Term: 2025–2027
JK

Jonas Keita

Member Director

Investor Member representative; runs our quarterly investor briefings.

Term: 2026–2028
AS

Adaeze Imafidon

Membership Secretary

Co-op secretary 12 yrs. Runs the General Assembly, voting platform & member onboarding.

Term: staff officer
Board size8 members · 6 elected, 2 independent NEDs
Quorum5 directors, at least 3 elected members
Director payVolunteer · vouched expenses only
AuditIndependent annual audit · accounts published
Conflicts of interestPublished register · reviewed at every AGM
Partners & affiliations

Who we work with.

Local councils, peer cooperatives, universities and regulated service providers — all named, none anonymous.

Local authority

Your Borough Council

Housing & Wellbeing partnership covering retrofits, damp surveys and allocations.

Academic

UCL Housing Health Lab

Joint research on indoor air quality, ventilation and respiratory outcomes in social housing.

Peer cooperative

Cooperativa Habitar, Lisbon

Sister housing co-op — bylaws partner, joint case studies, board exchange programme.

Network

Confederation of Co-operative Housing

National membership body. We follow their model rules and submit annual returns.

Payments

Stripe & Zeffy

Stripe for member fees (PCI-DSS, FCA-authorised). Zeffy for fee-free donations.

Insurance

FairLet Insurance Brokers

Co-op landlord insurance and trustee indemnity at a member-negotiated rate.

Audit

Atlas Surveyors & Mutual Audit Co-op

EPC & structural surveys (Atlas) and independent annual statutory audit (Mutual Audit).

Retrofit

NorthGas & GreenLeaf Roofing

PAS 2035 retrofit contractors for the Phase 1 cavity-wall and roof programme.

Community

Sheffield Tenants Co-op & Lambeth Pickleball

Local member groups that grow social wellbeing alongside the housing work.

Procurement principle. We prefer local, cooperative and member-owned suppliers wherever rates and quality match. Tender outcomes for contracts above £20,000 are published in the annual report and on the forum.

We started by trying to fix the damp in our own homes. We ended up with a blueprint that cooperatives on three continents now use.

HO
Helen OkaforFounding resident · Chair, Allocations Committee
Be Part Of It

Join a community that thinks globally and acts locally.

Whether you want to live cooperatively, research with us, or simply fund the mission — there is a place for you here.