The five-point plans includes low deposit lending, with £10bn earmarked for first-time buyer mortgages, converting to new homes for 100,000 borrowers.
Nationwide made the move which it said reflects its “position as the UK’s largest member-owned organisation”.
The pledges include safeguarding the rates on its regular savings accounts, Help to Buy ISA and Save to Buy products to accelerate home ownership. The mutual will also establish a Brexit support group with representation from leading consumer bodies.
Nationwide’s chief executive, Joe Garner, said: “As a building society, we exist to help people into a home of their own and to help them manage their money and save for the future. Our mutual model means we’re able to plan and operate over the long term.
“In an uncertain economic climate, I believe that responsible and progressive businesses need to do more to help people realise their ambitions. With this in mind, I wanted to set out our five-point plan for how we will stand by our members and customers in uncertain times and help ensure that economic uncertainty doesn’t get in the way of the ladder of opportunity.”
Nationwide’s five-point plan:
1. Minimising costs for first time buyers
2. Maintaining low deposit lending
3. A £10bn a year commitment available to first time buyers
4. A savers’ support package
5. A Brexit consumer support panel