Yes it is.
There is no Overnight Allowance for official business at Westminster since the system was revamped in 2010.
If non-salaried Lords need to pay for an overnight stay it must come from the £300 Daily Attendance Allowance (or the £150 reduced allowance if applicable).
Salaried Lords cannot claim Attendance Allowance and their overnight expenses for Westminster business is explicitly covered by LOHA.
http://www.parliament.uk/about/mps-and-lords/about-lords/lords-allowances/
There is accommodation and subsistence expense cover for Parliamentary business away from Westminster
e.g. Brussels, Scottish Parliament, Devolved Assemblies, etc.;
in connection with the Lords Outreach Programme;
or as part of an official delegation to
i) the Council of Europe,
ii) NATO
iii) Organization for Security and Co-operation in Europe