Company lists · Data refreshed September 2026

Top 25 Net-zero retrofit consultants based in London, United Kingdom

RevenueBase identified 82 net-zero retrofit consultants headquartered in London, United Kingdom as of September 2026 and tracks 879 professional contacts across them, including 379 with verified work emails. Across the United Kingdom, London is the largest hub for this category.

This list covers net-zero retrofit consultants headquartered in London, United Kingdom, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 29, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 29, 2026 86% judged on-target in blind review
82Companies
879Contacts tracked
379Verified emails
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The 25 largest net-zero retrofit consultants based in London, United Kingdom

Ranked by team size
Top 25 of 82 net-zero retrofit consultants based in London, United Kingdom, ranked by team size, largest first. Data refreshed Sep 29, 2026. RevenueBase Smart Search rates how each company's information relates to net-zero retrofit consultants: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Partial evidenceLondon, United KingdomHQ checked Sep 29, 202651-200115 contacts →

Partial evidence

“Longevity Partners is a multidisciplinary energy and sustainability consultancy.”

Source: RevenueBase Database · checked Sep 29, 2026
2Strong evidenceLondon, United KingdomHQ checked Sep 29, 202651-20069 contacts →

Strong evidence

“Planet Mark is a sustainability certification and net zero provider for organisations and the built environment.”

Source: RevenueBase Database · checked Sep 29, 2026
3Partial evidenceLondon, United KingdomHQ checked Sep 29, 202651-20058 contacts →

Partial evidence

“We deliver retrofit and decarbonisation projects across London and the Thames Corridor, with the capability to operate nationally through the support of the Workplace Futures…”

Source: RevenueBase Database · checked Sep 29, 2026
4Indirect evidenceLondon, United KingdomHQ checked Sep 29, 202611-5048 contacts →

Indirect evidence

“Energy Industry Experts We are subject matter experts in the energy sector.”

Source: RevenueBase Database · checked Sep 29, 2026
5Partial evidenceLondon, United KingdomHQ checked Sep 29, 2026n/a37 contacts →

Partial evidence

“Mitie’s knowledge of customer estates, combined with our ability to execute a zero carbon strategy from assessment through to delivery is, we believe, unrivalled.”

Source: RevenueBase Database · checked Sep 29, 2026
6Partial evidenceLondon, United KingdomHQ checked Sep 29, 202611-5035 contacts →

Partial evidence

“Founded in 2010, Syzygy is the leading specialist low carbon technology consultancy for the real estate sector.”

Source: RevenueBase Database · checked Sep 29, 2026
7Strong evidenceLondon, United KingdomHQ checked Sep 29, 202611-5034 contacts →

Strong evidence

“Envision is a specialist sustainability, energy and net zero design consultancy offering strategic and technical advice within the built environment and to businesses wishing to…”

Source: RevenueBase Database · checked Sep 29, 2026
8Partial evidenceLondon, United KingdomHQ checked Sep 29, 202611-5034 contacts →

Partial evidence

“We’re helping to create a world where every building is truly zero carbon.”

Source: RevenueBase Database · checked Sep 29, 2026
9Partial evidenceLondon, United KingdomHQ checked Sep 29, 202611-5024 contacts →

Partial evidence

“Elevate is a leading engineering consultancy transforming urban infrastructure to revolutionise energy production and consumption.”

Source: RevenueBase Database · checked Sep 29, 2026
10Partial evidenceLondon, United KingdomHQ checked Sep 29, 202611-5023 contacts →

Partial evidence

“RetrofitWorks is a ‘not for private profit’ co-operative, matching communities & homeowners who want to retrofit their homes, with local, quality assured SME assessors and…”

Source: RevenueBase Database · checked Sep 29, 2026
11Indirect evidenceLondon, United KingdomHQ checked Sep 29, 202651-20018 contacts →

Indirect evidence

“At Domna, we are on a mission to make every home in Great Britain green and sustainable.”

Source: RevenueBase Database · checked Sep 29, 2026
12Partial evidenceLondon, United KingdomHQ checked Sep 29, 202611-5017 contacts →

Partial evidence

“We are at the forefront of retrofit design services for PAS 2035 & PAS 2038, delivering solutions that drive sustainability and efficiency through our vast combined retrofit…”

Source: RevenueBase Database · checked Sep 29, 2026
13Indirect evidenceLondon, United KingdomHQ checked Sep 29, 202611-5012 contacts →

Indirect evidence

“We design mechanical and electrical systems, advise on all aspects of energy, carbon reduction and building physics.”

Source: RevenueBase Database · checked Sep 29, 2026
14Indirect evidenceLondon, United KingdomHQ checked Sep 29, 202611-5010 contacts →

Indirect evidence

“At Henriksen Studio, our mission is to enhance the performance of both new and existing buildings.”

Source: RevenueBase Database · checked Sep 29, 2026
15Partial evidenceLondon, United KingdomHQ checked Sep 29, 20261-108 contacts →

Partial evidence

“TF Energy is a leading force in the UK retrofit sector, recognised for delivering property upgrade projects to the highest standards.”

Source: RevenueBase Database · checked Sep 29, 2026
16Strong evidenceLondon, United KingdomHQ checked Sep 29, 202611-507 contacts →

Strong evidence

“ep group brings global experience to businesses, investors and governments to deliver net zero and regenerative infrastructure.”

Source: RevenueBase Database · checked Sep 29, 2026
17Strong evidenceLondon, United KingdomHQ checked Sep 29, 20261-107 contacts →

Strong evidence

“We (Smart Green Shift Ltd) are a consulting firm that provides a wide range of services in net-zero carbon building design and Excellence in Design for Greater Efficiencies (EDGE)…”

Source: RevenueBase Database · checked Sep 29, 2026
18Partial evidenceLondon, United KingdomHQ checked Sep 29, 202611-505 contacts →

Partial evidence

“Cast Contracts specialise in commercial office low carbon retrofit and associated decarbonisation services.”

Source: RevenueBase Database · checked Sep 29, 2026
19Indirect evidenceLondon, United KingdomHQ checked Sep 29, 202611-505 contacts →

Indirect evidence

“Marie Claire Sustainability Technology Award Winner 2023.”

Source: RevenueBase Database · checked Sep 29, 2026
20Strong evidenceLondon, United KingdomHQ checked Sep 29, 20261-105 contacts →

Strong evidence

“Founded by Longevity Partners, Longevity Power is an independent sustainability and renewable energy consulting company that can support your Net Zero strategy with projects…”

Source: RevenueBase Database · checked Sep 29, 2026
21Partial evidenceLondon, United KingdomHQ checked Sep 29, 20261-105 contacts →

Partial evidence

“The ZED-Power team can offer consultancy in architecture, construction detailing and cost-effective delivery, product design, master planning, renewable energy and the development…”

Source: RevenueBase Database · checked Sep 29, 2026
22Strong evidenceLondon, United KingdomHQ checked Sep 29, 20261-104 contacts →

Strong evidence

“Susesco is a specialist boutique consultancy in net zero carbon and renewable energy.”

Source: RevenueBase Database · checked Sep 29, 2026
23Indirect evidenceLondon, United KingdomHQ checked Sep 29, 20261-103 contacts →

Indirect evidence

“Studio MASH is an architecture and design practice based in London.”

Source: RevenueBase Database · checked Sep 29, 2026
24Indirect evidenceLondon, United KingdomHQ checked Sep 29, 20261-102 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 29, 2026
25Indirect evidenceLondon, United KingdomHQ checked Sep 29, 20261-102 contacts →

Indirect evidence

“Are your costs increasing each time you renew your company's energy contracts?”

Source: RevenueBase Database · checked Sep 29, 2026

Showing 25 of 82 net-zero retrofit consultants based in London, United Kingdom

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Net-zero retrofit consultants based in London, United Kingdom at a glance

As of Sep 29, 2026
43.1%Verified-email coverage
10.7Average contacts per company
1-10Median size (employees)
Sep 29, 2026Page data refreshed

Companies by employee count

1-10
50
11-50
23
51-200
6
201-500
1
10001+
1

Email recency for this list is measured across the whole United Kingdom list rather than for London, so it is reported there. Company counts and contact totals on this page are exact for London, over 82 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among net-zero retrofit consultants, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in London, United Kingdom whose own description of what they do matches “net-zero retrofit consultants”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names net-zero retrofit consultants), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among net-zero retrofit consultants, and records with no verified work email. Companies headquartered outside London are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 379 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 29, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names net-zero retrofit consultants, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many net-zero retrofit consultants are there based in London, United Kingdom?

RevenueBase identified 82 net-zero retrofit consultants headquartered in London, United Kingdom as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Longevity Partners, headquartered in London, tops this list with the largest team on record.

Which city in the United Kingdom has the most net-zero retrofit consultants?

London leads the United Kingdom with 82 headquartered companies, followed by Manchester (14) and Bristol (13).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 379 verified decision-maker contacts tracked across these 82 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 29, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.