Householders who have signed up to solar rent-a-roof schemes may come a cropper unless there has been compliance with Council of Mortgage Lenders guidance.
Even so, there is a giant let-out as the guidance warns consumers that individual lenders may have their own specific requirements.
The CML guidance specifies that installers must have obtained all necessary consents, including that of the lender, before proceeding; installation must be carried out to an accredited standard; and the panels be properly maintained.
Any fees charged for repairs or maintenance must be no more than £60 per year.
Lenders must also be allowed to have the panels removed if the property is taking into possession and the installation of the panels is affecting attempts to sell the property or its resale value.
Peter Ambrose, of conveyancing firm The Partnership, has warned that owners of properties whose roofs have been leased out to solar energy firms may find their homes impossible to remortgage or to sell because prospective buyers cannot raise a mortgage.
His firm is dealing with one live case, but Ambrose thinks more are in the pipeline.
Meanwhile, a spokesman for Skipton Building Society clarified its lending position: "Skipton is prepared to lend, and indeed we have done, on homes subject to solar panel roof rental schemes.
"However, given the lack of standardisation in roof rental contracts, such applications do not qualify under our basic lending criteria. Nevertheless, we will consider applications on a case by case basis and are prepared to lend where the lease agreement meets our rigorous requirements for clarity regarding transfer of ownership, responsibility for maintenance costs of the panels, the expected shelf life of the panels and any damage their installation may cause to the property.
"We believe these factors are necessary to protect the value and saleability of the property, for the protection of both the borrower and us as lender."