Company lists · Data refreshed September 2026

Top 25 Retrofit contractors based in the United Kingdom

Name: Retrofit contractors based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 17, 2026 911 companies tracked

RevenueBase identified 911 company matches for retrofit contractors associated with the United Kingdom as of September 2026 and tracks 7,833 professional contacts across them, including 2,739 with verified work emails. London is the largest hub.

This list covers company matches for retrofit contractors associated with the United Kingdom, found by RevenueBase SmartSearch using the meaning of business descriptions in its company graph at Exact. Ranked by professionals tracked, largest first. Rows show recorded descriptions where available, Exact search membership and the snapshot date. Data refreshed September 17, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, 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 RevenueBase SmartSearch · Exact Recorded Sep 17, 2026 How this list was built

911Companies

7,833Contacts tracked

2,739Verified emails

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The 25 largest retrofit contractors based in the United Kingdom

Ranked by team size

Top 25 of 911 company matches for retrofit contractors based in the United Kingdom, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Sep 17, 2026. The RevenueBase SmartSearch column shows Exact match membership in this saved search. Click a contact count to view that company's people. Totals use company locations recorded by RevenueBase; the displayed preview is a smaller selection.
#	Company	RevenueBase SmartSearch	Headquarters	Employees	Contacts
1	SJS	Exact match	Musselburgh, United KingdomHQ recorded Sep 17, 2026	51-200	123 contacts →
	Exact match “SJS is a professional and well established fit-out and refurbishment contractor based in Musselburgh, with a reputation for affordable quality and exceptional service.” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
2	Instagroup LTD	Exact match	Finchampstead, United KingdomHQ recorded Sep 17, 2026	51-200	104 contacts →
	Exact match “Established in 1980, InstaGroup are a UK leader in the energy efficiency industry, covering commercial and residential projects.” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
3	Modutec	Exact match	Aberdeen, United KingdomHQ recorded Sep 17, 2026	51-200	103 contacts →
	Exact match “Repair, Conversion and New Build of Marine and Offshore Living Quarters and Technical Buildings.” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
4	Livgreen	Exact match	Bristol, United KingdomHQ recorded Sep 17, 2026	201-500	90 contacts →
	Exact match “We are a leading provider of retrofit residential decarbonisation across the UK.” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
5	Taylor And Fraser	Exact match	Paisley, United KingdomHQ recorded Sep 17, 2026	51-200	88 contacts →
	Exact match “As a leading contractor within the construction and engineering industry, and now a proud subsidiary of Suir Engineering, we deliver projects across a range of markets to our…” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
6	Gloster MEP LTD	Exact match	Southwark, United KingdomHQ recorded Sep 17, 2026	51-200	85 contacts →
	Exact match “Gloster MEP Ltd are a dynamic driven Mechanical and Electrical Contractor, well known within the industry for successfully delivering building services solutions to the Central…” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
7	Purdy Part Of Sureserve	Exact match	London, United KingdomHQ recorded Sep 17, 2026	201-500	85 contacts →
	Exact match “Who are we?” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
8	Sustainable Building Services UK LTD	Exact match	Skelmersdale, United KingdomHQ recorded Sep 17, 2026	51-200	82 contacts →
	Exact match “Are you looking for a specialist retrofit decarbonisation & energy efficiency contractor?” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
9	Next Energy	Exact match	Knowsley, United KingdomHQ recorded Sep 17, 2026	51-200	68 contacts →
	Exact match “Established in 2016, we have grown to become one of the most reputable and reliable specialists within the renewable, heating, and insulation sectors in the United Kingdom.” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
10	21 Degrees	Exact match	Nationwide, United KingdomHQ recorded Sep 17, 2026	201-500	65 contacts →
	Exact match “At 21 Degrees, we believe buildings should be designed for lower energy use, healthier spaces and better comfort.” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
11	Scis Group	Exact match	Fareham, United KingdomHQ recorded Sep 17, 2026	51-200	60 contacts →
	Exact match “Hello.” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
12	The Improveasy Group	Exact match	Altrincham, United KingdomHQ recorded Sep 17, 2026	51-200	58 contacts →
	Exact match “Energy solutions made easy.” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
13	AMBIT	Exact match	London, United KingdomHQ recorded Sep 17, 2026	51-200	58 contacts →
	Exact match “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…” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
14	Broad OAK Group	Exact match	Kingsley Moor, United KingdomHQ recorded Sep 17, 2026	201-500	58 contacts →
	Exact match “Delivering Excellence in Housing Decarbonisation Broad Oak specialises in delivering high-quality decarbonisation and retrofit solutions.” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
15	Primech Building Services LTD	Exact match	Gillingham, United KingdomHQ recorded Sep 17, 2026	51-200	57 contacts →
	Exact match “Primech is a specialist mechanical and electrical design and build contractor, with a strong focus on retrofit and upgrade projects across existing buildings and live environments.” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
16	IZ Energy Services LTD	Exact match	Barking, United KingdomHQ recorded Sep 17, 2026	51-200	57 contacts →
	Exact match “IZ Energy is pioneering a sustainable future.” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
17	Forcia Limited	Exact match	London, United KingdomHQ recorded Sep 17, 2026	51-200	55 contacts →
	Exact match “Forcia Limited is a construction company based out of Park Hill, London, United Kingdom.” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
18	ECO Providers	Exact match	Clitheroe, United KingdomHQ recorded Sep 17, 2026	51-200	51 contacts →
	Exact match “ECO Providers is a trusted leader in renewable and energy efficiency solutions, helping homeowners, businesses, and social housing organisations reduce energy costs, improve…” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
19	MP Group UK	Exact match	Glasgow, United KingdomHQ recorded Sep 17, 2026	201-500	47 contacts →
	Exact match “Construction group specialising in energy efficiency, fit out, M&E, fire & security and renewables.” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
20	Green Home Systems	Exact match	Irvine, United KingdomHQ recorded Sep 17, 2026	51-200	47 contacts →
	Exact match “At Green Home Systems, we deliver whole-house retrofit solutions that make homes warmer, more energy efficient, and lower cost to run.” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
21	Cotswold Energy Group	Exact match	Stonehouse, United KingdomHQ recorded Sep 17, 2026	51-200	45 contacts →
	Exact match “Secure your greener future with renewable energy solutions!” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
22	Sureserve Energy Services North	Exact match	Brighouse, United KingdomHQ recorded Sep 17, 2026	1,001-5,000	43 contacts →
	Exact match “Sureserve Energy Services North is a leading national installer of insulation, heating solutions and renewable technologies.” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
23	Avonside Energy	Exact match	Rearsby, United KingdomHQ recorded Sep 17, 2026	201-500	42 contacts →
	Exact match “Avonside Energy: Your Partner in Sustainable Building Solutions At Avonside Energy, we are dedicated to delivering best-in-class services across: New Build Insulation…” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
24	Malcolm Building Services Limited	Exact match	London, United KingdomHQ recorded Sep 17, 2026	51-200	40 contacts →
	Exact match “Malcolm Building Services are a London based Mechanical and Electrical contractor specialising in Commercial & residential new build mixed use schemes.” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase
25	B-Engineering Group Certified B Corp	Exact match	Warrington, United KingdomHQ recorded Sep 17, 2026	51-200	39 contacts →
	Exact match “We are a purpose driven engineering business, passionate about our people and the environment.” Recorded in the RevenueBase company graph · Sep 17, 2026 · View company records in RevenueBase

RevenueBase SmartSearch

Describe a niche business in your own words. RevenueBase SmartSearch compares the meaning of your description with company business descriptions compiled in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit.

This list uses Exact for “retrofit contractors”. Each Exact match badge shows membership in that saved search; it is not an individual similarity score or a service-quality rating. Recorded descriptions are shown where available.

Showing 25 of 911 retrofit contractors based in the United Kingdom

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Retrofit contractors based in the United Kingdom at a glance

As of Sep 17, 2026

35.0%Verified-email coverage

8.6Average contacts per company

11-50Median size (employees)

10.5%Largest-city concentration · London

Sep 17, 2026Page data refreshed

Companies by employee count

1-10

424

11-50

369

51-200

201-500

1,001-5,000

5,001-10,000

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 911 companies.

How this list was built

The recorded descriptions help you assess these company matches. Check a company’s website for its current services and locations.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
What qualifies: Company records associated with the United Kingdom whose business descriptions match “retrofit contractors” by meaning at the Exact setting. Descriptions are compiled in the RevenueBase company graph from public websites, profiles and company information where available; they are not guaranteed quotations from the company's website.
RevenueBase SmartSearch: Describe a niche company in your own words to find businesses by meaning. Exact, Similar, Related and Broad control the breadth of RevenueBase SmartSearch. This saved list uses Exact. Each row's Exact match badge shows inclusion in that search, not an individual score or a service-quality judgment.
Public preview: The public preview omits records without a verified work email. Where headquarters information is recorded, preview rows are also filtered to this page’s location. Dataset totals and geographic summaries describe the full matched records before these preview filters.
Match quality: RevenueBase's August 25, 2026 study assessed 4,198 description/company pairs across matching settings. The publisher reports 86% good or better at Exact. This evaluates the method across queries; it does not audit this individual list. Recorded company descriptions, where available, help you judge each match yourself. Read the full methodology: how the lists are built and what the study measures.
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 displayed company carries at least one verified work email. RevenueBase tracks 2,739 professional contacts with verified work emails across the full matched dataset. 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 17, 2026. Lists refresh periodically as the graph is re-checked.
Record context: Company records and descriptions can change. Check the company's website for its current services and locations.

Frequently asked

What is RevenueBase SmartSearch?

RevenueBase SmartSearch finds niche companies by the meaning of their business descriptions in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit your description. This list uses Exact for “retrofit contractors”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many retrofit contractors are there based in the United Kingdom?

RevenueBase identified 911 company matches for retrofit contractors associated with the United Kingdom as of September 2026, using the meaning of business descriptions at Exact. This is the recorded matched set in the RevenueBase company graph.

What is the largest company on this list?

SJS tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which city has the most retrofit contractors?

London leads with 96 company records, followed by Manchester (17) and Glasgow (16).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work limited free results with 500 credits to start. Upgrading provides access to the 2,739 professional contacts with verified work emails tracked across these 911 companies; direct dials are available where recorded.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 17, 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 SmartSearch, 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.