Company lists · Data refreshed September 2026

Top 23 Building efficiency venture firms based in the United Kingdom

Name: Building efficiency venture firms based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 16, 2026 91 companies tracked

RevenueBase identified 91 building efficiency venture firms headquartered in the United Kingdom as of September 2026 and tracks 635 professional contacts across them, including 267 with verified work emails. London is the largest hub.

This list covers building efficiency venture firms headquartered in the 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 16, 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 16, 2026 86% judged on-target in blind review

91Companies

635Contacts tracked

267Verified emails

Explore this list → Free signup · no credit card · 500 free credits

The 23 largest building efficiency venture firms based in the United Kingdom

Ranked by team size

Top 23 of 91 building efficiency venture firms based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 16, 2026. RevenueBase Smart Search rates how each company's information relates to building efficiency venture firms: 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.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Greenfield	Indirect evidence	Kings Cross, United KingdomHQ checked Sep 16, 2026	11-50	41 contacts →
	Indirect evidence “Greenfield specialise in the investment, development and delivery of sustainable and renewable-led infrastructure projects.” Source: RevenueBase Database · checked Sep 16, 2026
2	Haydale	Strong evidence	Ammanford, United KingdomHQ checked Sep 16, 2026	51-200	32 contacts →
	Strong evidence “Haydale is an advanced materials and technology company focused on improving the efficiency, performance and sustainability of buildings and infrastructure.” Source: RevenueBase Database · checked Sep 16, 2026
3	Asper Investment Management	Partial evidence	London, United KingdomHQ checked Sep 16, 2026	11-50	32 contacts →
	Partial evidence “Asper Investment Management is a leading specialist investment management firm focused on building large-scale sustainable energy platforms.” Source: RevenueBase Database · checked Sep 16, 2026
4	PI Labs	Indirect evidence	London, United KingdomHQ checked Sep 16, 2026	11-50	28 contacts →
	Indirect evidence “The VC backing the innovators who are transforming our relationship with the built world and its impact on people, business, and the environment.” Source: RevenueBase Database · checked Sep 16, 2026
5	Zestec Renewable Energy	Indirect evidence	Bournemouth, United KingdomHQ checked Sep 16, 2026	11-50	28 contacts →
	Indirect evidence “Owned by funds advised by Octopus Energy Generation, one of Europe’s largest renewable energy investors currently managing renewable assets totalling more than £5bn, we are…” Source: RevenueBase Database · checked Sep 16, 2026
6	Larkfleet Group Part Of Phoenix Sustainable Investments	Indirect evidence	Bourne, United KingdomHQ checked Sep 16, 2026	11-50	26 contacts →
	Indirect evidence “Larkfleet Group is now a part of Phoenix Sustainable Investments - an award-winning developer of sustainable energy projects.” Source: RevenueBase Database · checked Sep 16, 2026
7	Making Energy Greener	Indirect evidence	Southport, United KingdomHQ checked Sep 16, 2026	51-200	21 contacts →
	Indirect evidence “With over 20 years of experience in the energy services sector, Making Energy Greener are committed to transforming our community's homes with innovative energy-saving products…” Source: RevenueBase Database · checked Sep 16, 2026
8	Taranis	Indirect evidence	London, United KingdomHQ checked Sep 16, 2026	1-10	19 contacts →
	Indirect evidence “Taranis is an investment and asset management company owned by the Perenco Group.” Source: RevenueBase Database · checked Sep 16, 2026
9	Tallarna	Indirect evidence	London, United KingdomHQ checked Sep 16, 2026	11-50	15 contacts →
	Indirect evidence “Tallarna is a climate tech and finance platform for sustainable impact.” Source: RevenueBase Database · checked Sep 16, 2026
10	Reef Origin	Indirect evidence	London, United KingdomHQ checked Sep 16, 2026	11-50	14 contacts →
	Indirect evidence “Core Areas- Real estate & knowledge infrastructure - Digital & clean energy systems - Life sciences, research & innovation hubs - Logistics, automation & advanced manufacturing -…” Source: RevenueBase Database · checked Sep 16, 2026
11	United Capital	Partial evidence	London, United KingdomHQ checked Sep 16, 2026	501-1,000	14 contacts →
	Partial evidence “United Capital Group invest in consolidating the fragmented UK building and home services market, with a primary focus on the de-carbonisation of the sector.” Source: RevenueBase Database · checked Sep 16, 2026
12	HYCAP	Indirect evidence	Oxford, United KingdomHQ checked Sep 16, 2026	11-50	13 contacts →
	Indirect evidence “HYCAP is a global investment firm leading the energy transition through strategic investments across Private Equity, Technology, and Infrastructure.” Source: RevenueBase Database · checked Sep 16, 2026
13	Clean Growth Fund	Strong evidence	London, United KingdomHQ checked Sep 16, 2026	1-10	13 contacts →
	Strong evidence “CGF invest in tech innovations that reduce greenhouse gas emissions or improve resource efficiency across power, transport, industry, buildings, waste and water.” Source: RevenueBase Database · checked Sep 16, 2026
14	NOA	Indirect evidence	London, United KingdomHQ checked Sep 16, 2026	11-50	13 contacts →
	Indirect evidence “noa is Europe's largest built world VC firm, backing the founders rebuilding the physical world.” Source: RevenueBase Database · checked Sep 16, 2026
15	Buckthorn Partners LLP	Partial evidence	London, United KingdomHQ checked Sep 16, 2026	1-10	11 contacts →
	Partial evidence “Buckthorn invests in industrial businesses providing products and services that support the growth and integration of renewable energy, lower emissions, energy efficiency and…” Source: RevenueBase Database · checked Sep 16, 2026
16	Susten	Indirect evidence	London, United KingdomHQ checked Sep 16, 2026	11-50	11 contacts →
	Indirect evidence “We invest in new energy technologies.” Source: RevenueBase Database · checked Sep 16, 2026
17	Telis Energy	Indirect evidence	London, United KingdomHQ checked Sep 16, 2026	1-10	11 contacts →
	Indirect evidence “Telis Energy is a UK-based green energy projects developer and investor.” Source: RevenueBase Database · checked Sep 16, 2026
18	HG Ventures	Indirect evidence	Chipping Campden, United KingdomHQ checked Sep 16, 2026	51-200	10 contacts →
	Indirect evidence “We identify markets where we look to make a meaningful and positive difference.” Source: RevenueBase Database · checked Sep 16, 2026
19	Sabien Technology Group PLC	Partial evidence	London, United KingdomHQ checked Sep 16, 2026	11-50	8 contacts →
	Partial evidence “Sabien Technology Group is a company focused on building a portfolio of solutions, in the heating, cooling and transportation sectors, that deliver immediate reductions in CO2…” Source: RevenueBase Database · checked Sep 16, 2026
20	Econest	Indirect evidence	London, United KingdomHQ checked Sep 16, 2026	1-10	8 contacts →
	Indirect evidence “Econest is an AI-enabled asset manager that sources and purchases energy inefficient properties to retrofit and manage at scale for large investment portfolios.” Source: RevenueBase Database · checked Sep 16, 2026
21	Sustainable Future Ventures	Indirect evidence	London, United KingdomHQ checked Sep 16, 2026	1-10	6 contacts →
	Indirect evidence “Investing in technology companies that enable a more sustainable built environment.” Source: RevenueBase Database · checked Sep 16, 2026
22	Oasthouse Ventures Limited	Partial evidence	Brighton, United KingdomHQ checked Sep 16, 2026	1-10	5 contacts →
	Partial evidence “Oasthouse Ventures develop businesses which have a positive impact on the world.” Source: RevenueBase Database · checked Sep 16, 2026
23	Columbus Energy Partners Companies	Partial evidence	Glasgow, United KingdomHQ checked Sep 16, 2026	11-50	5 contacts →
	Partial evidence “Columbus Energy Partners® companies provide venture fixer and venture builder services to develop pioneering companies into replicable commercially sustainable branded businesses.” Source: RevenueBase Database · checked Sep 16, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: building efficiency venture firms. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names building efficiency venture firms.
Partial evidence: Its own public description names part of building efficiency venture firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name building efficiency venture firms. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 23 of 91 building efficiency venture firms based in the United Kingdom

See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 267 reachable decision-makers.

Free signup · no credit card

View the full list →

Building efficiency venture firms based in the United Kingdom at a glance

As of Sep 16, 2026

42.0%Verified-email coverage

7.0Average contacts per company

1-10Median size (employees)

71.4%Largest-city concentration · London

Sep 16, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

501-1,000

Email recency for this list is measured worldwide rather than for United Kingdom, so it is reported there. Company counts and contact totals on this page are exact for United Kingdom, over 91 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 building efficiency venture firms, 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 the United Kingdom whose own description of what they do matches “building efficiency venture firms”. 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 building efficiency venture firms), 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 building efficiency venture firms, and records with no verified work email. Companies headquartered outside United Kingdom 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, 267 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 16, 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.

Building efficiency venture firms by metro

Building efficiency venture firms in London65

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 building efficiency venture firms, 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 building efficiency venture firms are there based in the United Kingdom?

RevenueBase identified 91 building efficiency venture firms headquartered in the 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?

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

Which city has the most building efficiency venture firms?

London leads with 65 headquartered companies, followed by Glasgow (3) and Birmingham (2).

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 267 verified decision-maker contacts tracked across these 91 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 16, 2026.

Ready to reach these companies? Verified emails and direct dials for all 91 building efficiency venture firms based in the United Kingdom. Start with a free account, no credit card.

Download this list →

Related lists

Building efficiency venture firms by geography

Browse the directory

Browse: Companies home · All United Kingdom lists · All Building efficiency venture firms lists · New lists

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.