We’re expanding our offering for unique off-site construction mortgages.

Ecology Building Society sustainable mortgages and savings logo 2

We’re teaming up with more suppliers for our unique off-site build mortgages.

These unique mortgages support borrowers who want to build their own home using off-site construction.

Our latest suppliers are:

  • Beattie Passive
  • SIP Build
  • SIPS@Clays

They join our existing partners:

  • Agile Homes
  • HebHomes
  • Nhouse
  • R. House

We were the first UK lender to introduce dedicated mortgages for off-site construction homes. This is where modular sections of a property are made indoors in a factory and assembled on-site. The technique is sometimes called Modern Methods of Construction (MMC).

We were also the first lender to offer our mortgages in partnership with leading manufacturers. We’re now working with seven businesses across the UK and are looking for further partners.

Borrowers can choose from two different Ecology products:

  • Off-site Build mortgage, with staged release of funding as the project progresses
  • Off-site Build mortgage (Advance Payments), where a part of the mortgage advance can be secured against the modular components before construction starts.

At the end of their build, borrowers can benefit from our unique C-Change discount. This reduces their variable mortgage rate by up to 1.50% in recognition of the work they’ve done to cut their carbon footprint.

Dan Capstick, Ecology Building Society’s Mortgage Product Manager said:

“More than half of all self-builders use off-site construction* so we wanted to develop mortgages which specifically supported this growing group of borrowers.

With that in mind, we created the unique Advance Payments option, as we understand this type of self-build can have high upfront costs to buy the modular kit, just at a time when homebuyers may have spent much of their savings on buying the land, planning costs and utility connections.

Finding a site is the biggest challenge facing self-builders but managing cash flow during the project can be daunting so we looked at ways we could ease this process for borrowers during their build.

Working with the modular construction suppliers through our Off-site Build mortgages potentially opens up self-build to more borrowers who might have thought this wasn’t possible for them.

We also hope our innovation in this sector will support moves to scale up modular construction, which could help to deliver more homes more quickly to reduce the UK’s housing shortfall.

Off-site construction offers the opportunity to build high-quality homes to a more consistent standard, which also are more energy efficient. Construction has a lower carbon footprint, generally takes less time than a conventional building and creates less waste.

Ron Beattie, Managing Director, Beattie Passive said:

With a desire for their homes to have energy efficient, net zero credentials combined with fast delivery and high quality, more and more of our Self Build clients are looking for offsite solutions to deliver their dream homes.

We are pleased to be partnering with Ecology Building Society to enable our clients to access mortgages that are tailored to their needs.

Chris Duckworth, Managing Director, SBUK Group said:

SIP Build UK is excited to partner with Ecology Building Society, as their innovative new mortgages will empower more individuals to fund and build their dream homes.

Ian Clay, Founding Partner, SIPS@Clays said:

We’ve been at the heart of the SIPs industry for the past 20 years and we are mindful of the difficulties that some self-builders experience with funding their projects and accessing cash through traditional mortgages.

As such, we’re delighted to become one of Ecology’s selected partners and to be able to confidently point our customers to a lender whose specialised products are uniquely tailored to the off-site construction sector.

*2022 report, NaCSBA, the National Custom & Self Build Association

About our partners

Beattie Passive

Beattie Passive was the first company in the UK to be awarded Passivhaus certification for a complete build system. They have since become a leading provider of modular Passivhaus homes in the UK, committed to building high performing homes that can help reduce energy requirements and cut carbon. Their flexible, high performance build system delivers a range of products across self-build, residential and commercial markets.


SIP Build

SIP Build UK is part of the market-leading SBUK Group. For over a decade SIP Build UK take great pride in the design and manufacture of high performance, thermally efficient buildings delivered and installed within budget on site on time. With extensive knowledge and years of experience they cover the length and breadth of England and Wales. Offering SIP, Timber Frame, Cladding and Light Steel Frame Systems they pride themselves on a consultative approach.



SIPS@Clays: Established in 2003, SIPS@Clays is the UK’s leading provider of Structural Insulated Panels (SIPs). As the original delivery partner of the market leading Kingspan TEK® Building System, SIPS@Clays designs, fabricates and installs SIPs for self-build and commercial projects across the country.


Published: 14 December 2023

Author: Chris Meadows